RIDGID K-750 User manual

Drain Cleaning
Machine
OPERATOR’S
MANUAL
K-750
WARNING!
Read this Operator’s Manual
carefully before using this
tool. Failure to understand
and follow the contents of
this manual may result in
electrical shock, fire and/or
serious personal injury.
99 Washington Street
Melrose, MA 02176
Phone [phone]
Toll Free 1-800-517-8431
Visit us at www.TestEquipmentDepot.com

ii
Table of Contents
Recording Form for Machine Model and Serial Number............................................................................................1
General Safety
Work Area Safety........................................................................................................................................................2
Electrical Safety...........................................................................................................................................................2
Personal Safety...........................................................................................................................................................2
Tool Use and Care......................................................................................................................................................3
Service ........................................................................................................................................................................3
Specific Safety Information
Drain Cleaner Safety...................................................................................................................................................3
Description, Specifications and Standard Equipment
Description ..................................................................................................................................................................4
Specifications..............................................................................................................................................................4
Standard Equipment....................................................................................................................................................4
Machine Assembly
Instructions For Mounting Handles and Belt Guard ....................................................................................................5
Instructions For Installing Cable..................................................................................................................................5
Machine Inspection .......................................................................................................................................................5
Machine Set-Up..............................................................................................................................................................6
Operating Instructions
Using Power Feed Machine........................................................................................................................................8
Power Feed Adjustment Procedure ............................................................................................................................9
Using Manual Feed Machine.......................................................................................................................................9
Special Procedures
Main Sewer or Septic Tank Overrun.........................................................................................................................10
Starting Cutter Through P-Trap.................................................................................................................................10
Adding Additional Cable – Power Feed Machine......................................................................................................10
Adding Additional Cable – Manual Feed Machine ....................................................................................................10
Reverse Operation....................................................................................................................................................11
Loading the Machine On Vehicle ..............................................................................................................................11
Drum Assembly Removal and Installation.................................................................................................................11
Pigtail Removal and installation ................................................................................................................................12
Draining Water From Drum.......................................................................................................................................13
Loading Cable In Drum – Powerfeed Machine..........................................................................................................13
Accessories ................................................................................................................................................................13
Maintenance
Lubrication.................................................................................................................................................................14
Powerfeed Assembly.................................................................................................................................................14
Cables.......................................................................................................................................................................14
Machine Storage..........................................................................................................................................................14
Service and Repair ......................................................................................................................................................14
Troubleshooting ..........................................................................................................................................................15
Wiring Diagram............................................................................................................................................................16
Lifetime Warranty..........................................................................................................................................Back Cover
K-750 Drain Cleaning Machine
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com

K-750 Drain Cleaning Machine
Record Serial Number below and retain product serial number which is located on nameplate.
Serial
No.
K-750
Drain Cleaning Machine
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - TestEquipmentDepot.com

K-750 Drain Cleaning Machine
Ridge Tool Company2
General Safety Information
WARNING! Read and understand all instructions. Failure
to follow all instructions listed below may
result in electric shock, fire, and/or serious
personal injury.
SAVE THESE INSTRUCTIONS!
Work Area Safety
•Keep your work area clean and well lit. Cluttered
benches and dark areas invite accidents.
•Do not operate tools in explosive atmospheres,
such as in the presence of flammable liquids,
gases, or dust. Tools create sparks which may ignite
the dust or fumes.
•Keep bystanders, children, and visitors away while
operating a tool. Distractions can cause you to lose
control.
Electrical Safety
•Grounded tools must be plugged into an outlet,
properly installed and grounded in accordance
with all codes and ordinances. Never remove the
grounding prong or modify the plug in any way.
Do not use any adapter plugs. Check with a qual-
ified electrician if you are in doubt as to whether
the outlet is properly grounded. If the tool should
electrically malfunction or break down, grounding pro-
vides a low resistance path to carry electricity away
from the user.
•Avoid body contact with grounded surfaces such
as pipes, radiators, ranges and refrigerators. There
is an increased risk of electrical shock if your body is
grounded.
•Don’t expose electrical tools to rain or wet condi-
tions. Water entering a tool will increase the risk of
electrical shock.
•Do not abuse cord. Never use the cord to carry the
tools or pull the plug from an outlet. Keep cord
away from heat, oil, sharp edges or moving parts.
Replace damaged cords immediately. Damaged
cords increase the risk of electrical shock.
•When operating a tool outside, use an outdoor
extension cord marked “W-A” or “W”. These cords
are rated for outdoor use and reduce the risk of elec-
trical shock.
•Use only three-wire extension cords which have
three-prong grounding plugs and three-pole re-
ceptacles which accept the tool’s plug. Use of other
extension cords will not ground the tool and increase
the risk of electrical shock.
•Use proper extension cords. (See chart.) Insufficient
conductor size will cause excessive voltage drop and
loss of power.
•Before using, test the Ground Fault Circuit Inter-
rupter (GFCI) provided with the power cord to in-
sure it is operating correctly. GFCI reduces the
risk of electrical shock.
•Extension cords are not recommended unless
they are plugged into a Ground Fault Circuit In-
terrupter (GFCI) found in circuit boxes or outlet
receptacles. The GFCI on the machine power cord will
not prevent electrical shock from the extension cords.
•Keep all electrical connections dry and off the
ground. Do not touch plugs or tool with wet hands.
Reduces the risk of electrical shock.
Personal Safety
•Stay alert, watch what you are doing and use com-
mon sense when operating a power tool. Do not
use tool while tired or under the influence of drugs,
alcohol, or medications. A moment of inattention
while operating power tools may result in serious per-
sonal injury.
•Dress properly. Do not wear loose clothing or jew-
elry. Contain long hair. Keep your hair, clothing,
and gloves away from moving parts. Loose clothes,
jewelry, or long hair can be caught in moving parts.
•Avoid accidental starting. Be sure switch is OFF
before plugging in. Carrying tools with your finger on
the switch or plugging tools in that have the switch ON
invites accidents.
•Remove adjusting keys or switches before turning
Minimum Wire Gauge for Extension Cord
Nameplate
Amps Total Length (in feet)
0 – 25 26 – 50 51 – 100
0 – 6 18 AWG 16 AWG 16 AWG
6 – 10 18 AWG 16 AWG 14 AWG
10 – 12 16 AWG 16 AWG 14 AWG
12 – 16 14 AWG 12 AWG NOT RECOMMENDED
Grounding prong
Cover of
grounded
outlet box
Grounding prong

K-750 Drain Cleaning Machine
Ridge Tool Company 3
the tool ON. A wrench or a key that is left attached to
a rotating part of the tool may result in personal injury.
•Do not over-reach. Keep proper footing and bal-
ance at all times. Proper footing and balance enables
better control of the tool in unexpected situations.
•Use safety equipment. Always wear eye protection.
Dust mask, non-skid safety shoes, hard hat, or hear-
ing protection must be used for appropriate conditions.
Tool Use and Care
•Use clamp or other practical way to secure and
support the workpiece to a stable platform. Holding
the work by hand or against your body is unstable
and may lead to loss of control.
•Do not force tool. Use the correct tool for your
application. The correct tool will do the job better
and safer at the same rate for which it is designed.
•Do not use tool if switch does not turn it ON or
OFF. Any tool that cannot be controlled with the switch
is dangerous and must be repaired.
•Disconnect the plug from the power source before
making any adjustments, changing accessories, or
storing the tool. Such preventive safety measures re-
duce the risk of starting the tool accidentally.
•Store idle tools out of the reach of children and
other untrained persons. Tools are dangerous in
the hands of untrained users.
•Maintain tools with care. Keep cutting tools sharp
and clean. Properly maintained tools with sharp cut-
ting edges are less likely to bind and are easier to
control.
•Check for misalignment or binding of moving
parts, breakage of parts, and any other condition
that may affect the tool's operation. If damaged,
have the tool serviced before using. Many acci-
dents are caused by poorly maintained tools.
•Use only accessories that are recommended by the
manufacturer for your model. Accessories that may
be suitable for one tool may become hazardous when
used on another tool.
•Keep handles dry and clean; free from oil and
grease. Allows for better control of the tool.
Service
•Tool service must be performed only by qualified
repair personnel. Service or maintenance performed
by unqualified repair personnel could result in injury.
•When servicing a tool, use only identical replace-
ment parts. Follow instructions in the Maintenance
Section of this manual. Use of unauthorized parts or
failure to follow maintenance instructions may create a
risk of electrical shock or injury.
Specific Safety Information
WARNING
Read this operator’s manual carefully before using
the RIDGID K-750 Drain Cleaner. Failure to under-
stand and follow the contents of this manual may
result in electrical shock, fire and/or severe per-
sonal injury.
Drain Cleaner Safety
•Wear gloves provided with the machine. Never
grasp a rotating cable with a rag or loose fitting
cloth glove. Could become wrapped around the cable
and cause serious injury.
•Never operate machine with belt guard removed.
Fingers can be caught between the belt and pulley.
•Do not overstress cables. Keep one hand on the
cable for control when the machine is running.
Overstressing cables may cause twisting or kinking
and result in serious injury.
•Position machine within three feet of inlet. Use
Front Guide Hose or properly support exposed
cable when it is difficult to locate the machine near
the access or clean out. Greater distances can result
in cable twisting or kinking.
•Machine is designed for one person operation.
Operator must control foot switch and cable.
•Use foot switch to operate machine while main-
taining good footing and balance. Do not operate
machine in (REV) reverse. Operating machine in re-
verse can result in cable damage and is used only to
back tool out of an obstruction.
•Keep hands away from rotating drum and guide
tube. Do not reach into drum unless machine is un-
plugged. Hand may be caught in the moving parts
resulting in serious injury.
•Use kickstand during operation. The kickstand sta-
bilizes machine to prevent tipping.
•Be careful when cleaning drains where cleaning
compounds have been used. Avoid direct contact
with skin and eyes. Serious burns can result from
some drain cleaning compounds.

K-750 Drain Cleaning Machine
Rating...........................1/2HP @ 1725 RPM
Amps............................6.5
Weight (Machine Only)..95 lbs.
Dimensions
Length..........................26″
Width............................21″
Height ..........................43″
Standard Equipment
Machine Options - Autofeed
Machine Options - Manual Feed
Standard 3/4″Tool Set Includes:
•T-406 Spear Blade Cutter
•T-407 Retrieving Auger
•T-411 2″Cutter
•T-413 3″Cutter
•T-414 4″Cutter
Standard 5/8″Tool Set Includes:
•T-403 3″P-Trap Cutter
•T-406 Spear Blade Cutter
•T-413 3″Cutter
•T-407 Retrieving Auger
•T-411 2″Cutter
Catalog No.
115V-60Hz 230V-50Hz
41977 44202
51402 51407
42002 44207
42007 44212
42012 44217
47047 —
Model Weight
No. Description lb. kg.
K-750 Machine with Gloves and 114 51.9
Autofeed - 3/4″Pigtail
K-750 Machine with Gloves and 113 51.3
Autofeed - 5/8″Pigtail
K-750 Machine with One Pair of Gloves, 206 93.6
w/C-75 Autofeed, Standard 3/4″Tool Set,
and C-75, 75′x 3/4″Cable
K-750 Machine with One Pair of Gloves, 234 106.3
w/C-100 Autofeed, Standard 3/4″Tool Set,
and C-100, 100′x 3/4″Cable
K-750 Machine with One Pair of Gloves, 182 82.7
w/C-27 Autofeed, Standard 5/8″Tool Set,
and C-27, 75′x 5/8″Cable
K-750 Machine with One Pair of Gloves,
w/C-24 Autofeed, Standard 5/8″Tool Set,
and C-24, 100′x 5/8″Cable
4
•Do not operate machine if operator or machine is
standing in water. Will increase the risk of electrical
shock.
•Wear safety glasses and rubber soled, non-slip
shoes. Use of this safety equipment may prevent se-
rious injury.
•Use the K-750 to only clean drain lines. Follow in-
structions on the use of the machine. Other uses or
modifying the drain cleaner for other applications may
increase the risk of injury.
Description, Specifications and
Standard Equipment
Description
The RIDGID K-750 Drain Cleaning Machine will clean
drain lines 3″to 10″in diameter and 200 feet in length de-
pending on size of cable. Corrosion resistant cable drum
holds 100 feet of 3/4″diameter cable or 125 feet of 5/8″di-
ameter cable. Cable spins at 200 RPM.
The drum is belt-driven by a 1/2HP electric motor that
has a grounded electrical system. An integral Ground
Fault Interrupter (GFCI) is built into the line cord. A “kick-
stand”base is provided for machine stability during
operation. A pneumatic foot actuator provides ON/OFF
control of the motor.
The cable has a quick change coupling system for con-
necting or disconnecting tools. An optional power feed
advances or retracts the cable at a rate up to 20 feet per
minute. A manual feed option is also available.
Specifications
Line Capacity..................Depends on choice of cable.
Refer to the following chart for
recommendations.
NOTE! Inner-Core Cable is not recommended for use
through P-Traps and severe bends in lines
smaller than 4″.
Optional 24″flexible trap leaders can be added
to aid users through traps and tight clean-outs.
Drum Capacity...............100′of 3/4″Cable or
125′of 5/8″Cable
Motor...............................115V, Reversible, Single
Phase, AC (60 Hz)
Cable Size Recommended Line
and Type Size and Reach
Line Size Reach
All 5/8″Cable 3″to 4″200′
3/4″Hollow Core 3″to 6″200′
3/4″Inner Core 4″to 10″200′
51342 — K-750 Machine with One Pair of Gloves 104 47.3
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com

K-750 Drain Cleaning Machine
Ridge Tool Company 5
Figure 1 – K-750 with Power Feed and C-100 Cable
Machine Assembly
WARNING
To prevent serious injury, proper assembly of the
Drain Cleaner is required. The following proce-
dures should be followed:
Instructions For Mounting Handles and
Belt Guard
Handles –Assemble handles to machine frame and se-
cure with two (2) belt guard screws.
Belt Guard –Check the belt guard to ensure that it is
approximately 1/4″from the drum. Reposition guard if
necessary and tighten bolts (Figure 3).
Gap between belt guard and drum should
not exceed 1/2″to prevent fingers being caught between
belt and pulley. Do not operate machine without belt
guard.
Instructions For Installing Cable
Do not remove bands or staples from
cable shipping carton. Cable is under tension and will whip
causing injury.
Retrieve end of cable through the center hole of carton and
remove enough cable to connect with drum pigtail. Connect
to pigtail by sliding cable couplings together and turning
screwdriver slot in coupler 180°. Couplings are in locked
position when hash mark is on opposite side of screwdriver
slot as shown in Figure 2. Manually feed cable into drum.
Machine Inspection
WARNING
To prevent serious injury, inspect your Drain
Cleaning Machine. The following inspection pro-
cedures should be performed before each use.
1. Make sure the Drain Cleaning Machine is unplugged
and the directional switch is set to the OFF position
(Figure 3).
2. Make sure the foot switch is present and attached to
the Drain Cleaning Machine (Figure 3). Do not oper-
ate the machine without a foot switch.
3. Inspect the power cord, Ground Fault Circuit Inter-
rupter (GFCI) and plug for damage. If the plug has
WARNING
CAUTION
Figure 2 – Disconnecting/Connecting Cable or Tool
QUICK-CONNECT CABLE & TOOLS
Rotate pin one-half turn in either direction
to quickly add cable or tools.
Hash Mark
(Locked position)
Screwdriver Slot
Hash Mark
(Un-locked position) Screwdriver Slot
LOCKED
Hash mark CLOSED aligned with Lstamped on coupling.
UNLOCKED
Hash mark OPEN aligned opposite Lstamped on coupling.
Coupling features stainless steel pin and spring: eliminates need for
punches, stands, or expansion pins.

Ridge Tool Company6
been modified, is missing the grounding prong or if the
cord is damaged, do not use the Drain Cleaning
Machine until the cord has been replaced.
Figure 3 – K-750 Drain Cleaning Machine with power feed
4. Inspect the Drain Cleaning Machine for any broken,
missing, misaligned or binding parts as well as any
other conditions which may affect the safe and normal
operation of the machine. If any of these conditions are
present, do not use the Drain Cleaning Machine until
any problem has been repaired.
5. Lubricate the Drain Cleaning Machine, if necessary,
according to the Maintenance Instructions.
6. Use tools and accessories that are designed for your
drain cleaner and meet the needs of your application.
The correct tools and accessories allow you to do the
job successfully and safely. Accessories suitable for
use with other equipment may be hazardous when
used with this drain cleaner.
7. Clean any oil, grease or dirt from all equipment han-
dles and controls. This reduces the risk of injury due
to a tool or control slipping from your grip.
8. Inspect the cutting edges of your tools. If necessary,
have them sharpened or replaced prior to using the
Drain Cleaning Machine. Dull or damaged cutting
tools can lead to binding and cable breakage.
9. Inspect cables and couplings for wear and damage.
Cables should be replaced when they become
severely worn or corroded. A worn cable can be iden-
tified when the outside coils become flat.
Worn or damaged cables can break caus-
ing serious injury.
Machine Set-Up
WARNING
To prevent serious injury, proper set-up of the machine
and work area is required. The following procedures
should be followed to set-up the machine:
1. Check work area for:
•Adequate lighting
•Grounded electrical outlet
•Clear path to the electrical outlet that does not
contain any sources of heat or oil, sharp edges or
moving parts that may damage electrical cord.
•Dry place for machine and operator. Do not use
the machine while standing in water.
•Flammable liquids, vapors or dust that may ignite.
2. Position the Drain Cleaning Machine within 3′of
sewer inlet.
If sewer inlet is greater than 3′from the
front of the machine, the cable will have a greater tendency
to twist or kink. Use a front guide hose or properly support
exposed cable.
3. Tilt machine forward and use your foot to extend “kick-
stands”so that machine rests firmly on them. For
best results, extend one kickstand and rest machine on
it before extending second kickstand. (Figure 4)
Figure 4 – Extending Kickstand
K-750 Drain Cleaning Machine
WARNING
Electrical
Switch
Belt Guard
Feed
Mechanism
Foot
Switch
Loading
Wheel
WARNING

Ridge Tool Company 7
To prevent tipping during use, machine
should rest firmly on the kickstand.
4. Position the air foot switch pedal for easy operator
accessibility. Machine is designed for one person
operation.
5. Make sure FOR/OFF/REV switch is in the OFF position.
6. Select and install the proper tool to the end of the
cable. Put screwdriver in slot, turn 180 degrees and
slide apart. To connect, slide tool or cable together
and turn screwdriver slot in coupler 180 degrees.
Coupling is in locked position when hash mark is on
opposite side of screwdriver slot as shown (Figure 2).
NOTE! Proper Tool Selection
A good rule of thumb is to use a tool at least 1″smaller
than the line to be cleaned. The style of the tool is de-
termined by the nature of the job and is left up to the
operator. A good starting tool is a spear cutter or blade
cutter.
NOTE! Trap Leaders
Inner-Core Cable is not recommended for use through P-
Traps and severe bends in lines smaller than 4″. A trap
leader, which is a flexible 2′length of cable, should be
connected to the front end of the cable.
7. Plug the Drain Cleaning Machine into the electrical
outlet, making sure to position the power cord along
the clear path selected earlier. If the power cord does
not reach the outlet, use an extension cord in good
condition.
To avoid electric shock and electrical
fires, never use an extension cord that is damaged or
does not meet the following requirements:
•The cord has a three-prong plug similar to the one
shown in Electrical Safety Section.
•The cord is rated as “W”or “W-A”if being used out-
doors.
•The cord has sufficient wire thickness (16 AWG
below 50′/14 AWG 50′-100′). If the wire thickness is
too small, the cord may overheat, melting the cord’s
insulation or causing nearby objects to ignite.
To reduce risk of electrical shock, keep all
electrical connections dry and off the ground. Do not
touch plug with wet hands. Test the Ground Fault Circuit
Interrupter (GFCI) provided with the electric cord to insure
it is operating correctly. When test button is pushed in, the
indicator light should go off. Reactivate by pushing the
reset button in. If indicator light goes on, the machine is
ready to use. If the GFCI does not function correctly, do
not use the machine.
Operating Instructions
WARNING
Wear gloves provided with machine. Never grasp a
rotating cable with a rag or loose fitting cloth
glove that may become wrapped around the cable
causing serious injury.
Always wear eye protection to protect your eyes
against dirt and other foreign objects. Wear rubber
soled, non-slip shoes.
Be careful when cleaning drains where cleaning
compounds have been used. Avoid direct contact
with skin and eyes.
Always assume the correct operating
posture in order to maintain proper balance (Figure 5).
Should an unexpected situation arise, this posture pro-
vides you with the opportunity to safely keep control of
the machine and cable.
•Be sure you can quickly remove your foot from the foot
switch.
•Hand must be on the cable to control its twisting action
when it hits an obstruction.
•Keep hands away from rotating drum and guide tube.
Do not reach into drum unless machine is unplugged.
Figure 5 – Proper Operating Position
K-750 Drain Cleaning Machine
WARNING
WARNING
WARNING
WARNING

8
Using Power Feed Machines
1. Loosen feed knob and manually pull sufficient cable
out of drum to start tool and cable into the sewer inlet.
NOTE! Make sure power feed is set for proper cable
size before engaging feed. Also, when running
5/8″cable with 3/4″pigtail, avoid power feeding 3/4″
pigtail through assembly. This practice can
cause premature failure of the bearings. (See
Powerfeed Adjustment Procedure)
2. Move FOR/OFF/REV switch into FOR (forward) po-
sition. Do not step on the air foot switch pedal at this
time.
3. To use feed mechanism, turn feed knob down until
front bearing makes contact with cable - turn one full
additional turn - do not over-tighten (over-tightening the
feed knob can cause premature bearing failure).
Loosely grasp cable with gloved hand and place right
hand on the feed lever. Feed lever should be in the
neutral position (vertical or 12 o’clock). Exert sufficient
downward pressure on cable to maintain control while
depressing foot actuator to start drum rotation. Do not
force the cable. Allow it to feed itself into the drain.
(See Special Procedures for negotiating traps.)
WARNING
Before starting machine, operator’s gloved hands
must be on the cable.
4. To power feed cable into line, move feed lever in
same direction as rotating drum and cable. Rate at
which cable is fed (0′- 20′per minute) into sewer is
controlled by position of feed lever away from neutral
(vertical) position.
WARNING
Always keep hand on the cable to feel tension.
5. Continue to feed the cable into the line until resis-
tance or obstruction is encountered. The condition will
generally become apparent to the operator as the
cable will have a tendency to twist sideways in the op-
erator’s hands.
6. Operator should immediately respond to this condition
by moving feed lever into full reverse (opposite di-
rection of drum rotation). This should release the
twist in cable and reduce size of cable loop.
7. Once free of this obstruction and the load is relieved
from the cable, gradually feed cable forward.
Remember, when using the feed mechanism the rate
of cable advance is controlled by the power feed han-
dle. Allow cutter to advance slowly and work through
the obstruction. If cable shows signs of loading (gen-
erally apparent by growing loop between machine
and drain), immediately back cutter from obstruction by
reversing feed.
NOTE! At this point, progress depends upon the sharp-
ness of the tool and the nature of the obstruction.
Continued operation should be in manual feed
mode until the obstruction has been cleared.
8. Manually pull back sharply on the cable to free the
cutter and relieve the load on the cable. Slowly ad-
vance cable back into the obstruction. Repeat this
process until the obstruction is clear. Remember,
make sure the cutter is rotating at all times and never
force the cable.
WARNING
Do not allow tension to build up in the cable. This
will happen if the cutting tool hits a snag and stops
turning, but the motor and its drum continue to ro-
tate. Torque builds until the cable suddenly twists,
potentially wrapping around your hand or arm. This
can happen quickly and without warning so pro-
ceed slowly and carefully as you feed the cable
into the drain. If tool gets hung up in an obstruction,
refer to Reverse Operating Instructions in the “Spe-
cial Procedures” section.
9. Several passes at a thoroughly blocked drain line
are recommended. After establishing flow, increase
cutter size to thoroughly clean line. Flush with strong
flow of water.
NOTE! Additional cable may be added. If required, refer
to “Special Procedures”.
10. To retrieve cable from sewer line, move the feed
lever in opposite direction of drum rotation. The cable
should now feed itself back into machine.
NOTE! It is recommended that a continuous flush of
water be used to clean cable and tool as they
are retrieved.
11. When the tool is just inside the sewer inlet, release the
air foot switch pedal and allow the machine to come to
a complete stop.
Never retract tool from sewer inlet while
cable is rotating. Tool can whip causing serious injury.
13. Turn FOR/OFF/REV switch to OFF position and re-
move cord from power source.
14. Loosen feed knob. Hand feed the cable into the
machine.
15. Disengage the kickstands by tilting the machine for-
ward.
K-750 Drain Cleaning Machine
WARNING
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com

Ridge Tool Company 9
Powerfeed Adjustment Procedure
WARNING
Make sure FOR/OFF/REV switch is in OFF position
and machine is unplugged from power source.
1. Put screwdriver in one of two slotted pins located on
front of power feed assembly (Figure 6). To power-
feed 3/4″cable, turn pin so that slot indicates 3/4mark
on body of assembly.
Figure 6 – Powerfeed Adjustment
NOTE! If pin seems to hit an interference, adjust position
of powerfeed lever until pin rotates freely into
position.
2. Repeat with the other slotted pin.
3. To power feed 5/8″cable, use same procedure to po-
sition slot so that it indicates 5/8mark on body of
assembly.
NOTE! When running 5/8″cable with a 3/4″pigtail, avoid
power feeding pigtail through the power feed as-
sembly. This practice can cause premature failure
of the bearings.
Using Manual Feed Machine
1. Manually pull a sufficient length of cable out of the
drum to start the tool and cable into the sewer inlet.
2. Move FOR/OFF/REV switch into FOR (forward) po-
sition. Do not step on the air foot switch pedal at
this time.
3. Pull 18″- 24″from the machine - enough to form a
slight loop - and apply downward pressure with both
hands on the cable. Do not force the cable. Allow it
to feed itself into the drain. (See “Special Procedures”
for negotiating through traps.)
WARNING
Before starting machine, both operator’s gloved
hands must be on the cable.
4. Exert sufficient downward pressure on cable to keep
it in sewer line while depressing air foot switch pedal
to start cable rotating.
5. Pull cable out of drum and allow cable to feed itself
into the line.
WARNING
Always keep hand on the cable to feel tension.
6. Continue to feed the cable into the line until resistance
or obstruction is encountered. The condition will gen-
erally become apparent to the operator as the cable
will have a tendency to twist sideways in the opera-
tor’s hands.
7. Pull back sharply on the cable to free the cutter and re-
lieve the load on the cable. Slowly advance cable
back into the obstruction. Repeat this process until the
obstruction is clear. Remember, make sure the cutter
is rotating at all times and never force the cable.
WARNING
Do not allow tension to build up in the cable. This
will happen if the cutting tool hits a snag and stops
turning, but the motor and its drum continue to ro-
tate. Torque builds until the cable suddenly twists,
potentially wrapping around your hand or arm. This
can happen quickly and without warning, so pro-
ceed slowly and carefully as you feed the cable into
the drain. If tool gets hung up in an obstruction,
refer to Reverse Operating Instructions in the
“Special Procedures” section.
NOTE! Additional cable may be added if required. Refer
to “Special Procedures”.
8. Several passes through thoroughly blocked drain
lines are recommended. After establishing drain flow,
increase cutter size to thoroughly clean the lines.
9. To retrieve cable from sewer line, pull cable into the
drum with machine in FOR (forward). The machine
should be kept running during the process for thorough
cleaning.
K-750 Drain Cleaning Machine
Neutral
Full
Advance Full
Retrieve
NOTE:
Rate of cable advance
or retrieve varies
by handle movement
from neutral.

K-750 Drain Cleaning Machine
4. Disconnect cable from pigtail. Make sure that it does
not slip down the drain/sewer inlet such that you can-
not reach it.
5. Stretch out additional cable and attach end of new
cable to pigtail and push cable-to-pigtail connection
back through power feed assembly. Tighten knob
and feed new cable into drum.
- or -
Remove empty drum assembly and mount new drum
assembly loaded with cable onto machine. (See Drum
Removal/Installation Procedure)
6. Attach front end of second cable to back end of cable
currently in the drain line and continue the feed op-
eration.
NOTE! Be sure entire cable and blade is rotating in
drain before feeding cable into drain.
NOTE! When you need to know how much cable you
have left in your drum, remember one wrap of
cable in your drum is approximately 4′.
Adding Additional Cable - Manual Feed
Machine
To run a second cable down the drain/sewer line, the fol-
lowing procedure should be followed.
1. Grasp and pull cable until cable-to-pigtail connection
is accessible.
2. Disconnect cable from pigtail. Make sure it does not
slip down the drain/sewer inlet such that you cannot
reach it.
3. Attach end of new cable to pigtail and feed new cable
into drum.
- or -
Remove empty drum assembly and mount new drum
assembly loaded with cable onto machine. (See Drum
Removal/Installation Procedure)
4. Attach front end of second cable to back end of cable
currently in the drain line and continue the feed op-
eration.
NOTE! Be sure entire cable and blade is rotating in
drain before feeding cable into drain.
NOTE! When you need to know how much cable you
have left in your drum, remember one wrap of
cable in your drum is approximately 4′.
Ridge Tool Company10
NOTE! A continuous flush of water should be used to
clean the cable and tool as they are retrieved.
10. When the tool is just inside the sewer inlet, release the
air foot switch pedal and allow the machine to come to
a complete stop.
Never retract tool from sewer inlet while
cable is rotating. Tool can whip causing serious injury.
11. Turn FOR/OFF/REV switch to OFF position and re-
move cord from power source.
12. Pull the remaining cable and tool from the sewer.
Hand feed the cable into the machine.
13. Disengage the kickstands by tilting the machine for-
ward.
Special Procedures
Main Sewer Or Septic Tank Overrun
It is very important to know the approximate distance from
inlet to main sewer or septic tank. Over-running cable
into main sewer or septic tank can cause cables to knot-up
and prevent their return through small lines.
Starting Cable Through P-Trap
A trap leader is recommended. Trap leaders are flexible
2’lengths of cable connected to the front end of cable.
Manual operation is recommended. Before starting ma-
chine, position cutter in bottom of trap (NOTE: Special
P-Trap Cutters are recommended), and pull enough
cable from machine to form a loop between machine and
drain opening. Push down sharply on the bend in cable.
A light tap in the foot pedal or hand turning the drum will
reposition the blade to allow easier passage through
the trap. Operator may choose to use powerfeed after ne-
gotiating trap.
Adding Additional Cable – Powerfeed
Machines
To run a second cable down the drain/sewer line, the fol-
lowing procedure should be followed:
1. Stop power feed operation before cable-to-pigtail
connection reaches power feed rollers.
2. Loosen feed knob.
3. Grasp and pull cable until cable-to-pigtail connection
passes through power feed assembly.
NOTE! When running 5/8″cable with 3/4″pigtail, avoid
power feeding 3/4″pigtail through assembly. This
practice can cause premature failure of the bear-
ings.
WARNING

K-750 Drain Cleaning Machine
Figures 7a and 7b – Use 3/4″Wrench to Remove Autofeed
Assembly
Ridge Tool Company 11
Reverse Operation
Running machine in reverse will cause premature failure
of cable. Use reverse only to free a tool caught in an
obstruction. If this should occur, immediately remove foot
from air foot switch pedal and allow machine to come to a
full and complete stop. Place FOR/OFF/REV switch to
REV (reverse) position. If machine has automatic feed,
loosen feed knob. Grasp cable with gloved hands and pull
while jogging air foot switch pedal. When tool is dis-
lodged and drum has stopped rotating, place FOR/-
OFF/REV switch in FOR (forward) position and follow
normal operating procedure.
Never operate this machine in REV (re-
verse) for any other purpose. Operating in reverse can
damage a cable and cause serious injury.
Loading The Machine On Vehicle
Tip machine backwards and rest handles on truck bed.
Lift up on front of machine and slide onto truck.
Use proper lifting technique - lift with your
legs, not your back.
NOTE! Take care not to damage electrical cord or air
foot switch hose.
Drum Removal & Installation Procedure
WARNING
Make sure FOR/OFF/REV SWITCH is in OFF position
and machine is unplugged from power source.
1. For powerfeed machines, use 3/4″wrench to remove
power feed assembly from front of machine. One
bolt holds assembly to frame. Bolt and assembly will
come off as one (Figures 7a and 7b).
2. Push down on motor table handle to release belt
tension and slip belt off drum (Figure 8).
3. Use 3/4″wrench to remove bolt that fastens drum as-
sembly to machine frame (Figure 9).
WARNING
WARNING

12
Figure 8 – Release Belt Tension
Figure 9 – Remove Bolt Which Fastens Drum Assembly
to Machine Frame
Figure 10 – Lift Drum from Mounting Position
4. Lay machine back so that it rests on handles. Grasp
drum with both hands and lift it out of its mounting po-
sition on machine (Figure 10).
To avoid back injury, be sure to bend
your knees and lift with your legs.
5. To install drum assembly, place it in its mount on
machine frame. Drum assembly should slide onto
shaft mounted on frame.
6. Carefully return machine to its upright position and re-
verse Steps 1 through 3 to prepare machine for
operation.
Pigtail Removal and Installation
WARNING
FOR/OFF/REV SWITCH should be OFF and machine
is unplugged before removing or installing pigtail.
1. Remove all cable from the drum except the pigtail.
2. Remove the bolt anchoring the pigtail. It is located on
the back of the drum (Figure 11).
K-750 Drain Cleaning Machine
CAUTION
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com

K-750 Drain Cleaning Machine
Ridge Tool Company 13
Figure 11 – Removing Pigtail Anchoring Bolt
3. Remove the pigtail from drum by pulling it through the
guide tube.
4. Insert new pigtail by pushing it through the guide tube
into the drum.
5. Align hole in pigtail fastener with the hole in the back
of the drum. Insert bolt, washers and nut and tighten
securely. Push the remainder of the pigtail into drum.
Draining Water From Drum
Orient drum so that drain hole in its back is down. Lay
machine on its back and water will drain from drum.
Remove plug with a flathead screwdriver.
Loading Cable In Drum – Powerfeed
Machines
For power feed machines, the cable can be loaded using
the feed mechanism. Lay entire length of cable on flat
surface in line with drum front. Start machine and adjust
feed mechanism to retract cable into drum. Note, cable
will move sideways on ground while in operation. Loading
with assistance of power feed will ensure cable lays
correctly in drum and eliminate chance of vibration.
Accessories
WARNING
Only the following RIDGID products have been designed
to function with the K-750 Drain Cleaning Machine. Other
accessories suitable for use with other tools may be-
come hazardous when used on the K-750. To prevent
serious injury, use only the accessories listed below.
Solid Core, Integral Wound Cables (IW) are stiffer, less
flexible versions of 5/8″cable.
Cables and Flexible Leaders
Model
No. Description
C-25 25′Flexible I.C. Cable (7,6m)
C-26 50′ Flexible I.C. Cable (15,2m)
C-27 75′ Flexible I.C. Cable (22,9m)
C-24 100′ Flexible I.C. Cable (30,5m)
C-24 IW 100′ IW Solid Core Cable
(Integral Wound) (30,5m)
C-27HC 75′Hollow Core (22,9m)
C-24HC 100′Hollow Core (30,5m)
C-28 25′I.C. Cable (7,6m)
C-29 50′I.C. Cable (15,2m)
C-75 75′I.C. Cable (22,9m)
C-100 100′I.C. Cable (30,5m)
C-75HC 75′Hollow Core (22,9m)
C-100HC 100′Hollow Core (30,5m)
T-458 5/8″x 2′Leader
T-468 3/4″x 2′Leader
—5/8″Pigtail
—3/4″Pigtail
Accessories
Model
No. Description
A-7558 Drum Assembly w/ 5/8″Pigtail
A-7534 Drum Assembly w/ 3/4″Pigtail
A-75 Power feed Assembly
—Front Guide Hose Assembly
—Pair of Work Gloves
A-3 Tool Box
—Cable Rust Inhibitor, 1 Quart
—Cable Rust Inhibitor, 1 Gallon
5/8" (16mm)
3/4" (20mm)
3/4" (20mm)
5/8" (16mm)

K-750 Drain Cleaning Machine
Ridge Tool Company14
* Includes Coupling and Fastener
Maintenance Instructions
WARNING
Make sure machine is unplugged from power source
before performing maintenance or making any ad-
justment.
Lubrication
Grease all exposed, moving and rotating parts as re-
quired.
Powerfeed Assembly
Proper cleaning and lubrication of the power feed as-
sembly is advised for long, trouble-free operation. After
each use, hose out power feed assembly with water
and lubricate with lightweight machine oil.
Cables
Drain drum after every use. Flush drum periodically, re-
move sediment that can corrode cable.
Cables should be thoroughly flushed with water to prevent
damaging effects of drain cleaning compounds. Periodi-
cally lubricate cables and couplings with RIDGID Cable
Rust Inhibitor. See Accessories for catalog information.
When not in use, store cables indoors to prevent dete-
rioration by the elements.
Cables should be replaced when they become severely
corroded or worn. A worn cable can be identified when
outside coils of cable become flat.
Machine Storage
WARNING
Motor-driven equipment must be kept indoors or well
covered in rainy weather. Store the machine in a locked
area that is out of reach of children and people unfamiliar
with drain cleaners. This machine can cause serious in-
jury in the hands of untrained users.
Service and Repair
WARNING
The “Maintenance Instructions”will take care of most of
the service needs of this machine.
Tools and Replacement Blades –Fits C-24, C-25, C-
26, C-27, C-28, C-29, C-75, C-100, C-27HC, C-24HC,
C-75HC, and C-100HC
Fastener*
Blade
Blade
Holder
Coupling*
Drum Tool Assembly
Model
No.
T-403
T-404
T-406
T-407
T-408
T-409
T-411
T-412
T-413
T-414
T-416
T-432
T-433
T-434
T-436
Blade(s)
92835
92840
92850
—
92890
—
92815
92820
92825
92830
92855
92860
92865
92870
92875
Holder
92900
92900
92915
—
92915
—
92905
92905
92910
92910
92910
92895
92895
92895
92895
Description
P-Trap Cutter, 3″
P-Trap Cutter, 31/2″
Spear Blade
Retrieving Auger
Sawtooth Cutter
H-D Bulb Auger
Double Cutter, 2″
Double Cutter, 21/2″
Double Cutter, 3″
Double Cutter, 4″
Double Cutter, 6″
3-Blade Cutter, 2″
3-Blade Cutter, 3″
3-Blade Cutter, 4″
3-Blade Cutter, 6″
Replacement
* Identifies components
included with holder

Ridge Tool Company 15
K-750 Drain Cleaning Machine
PROBLEM POSSIBLE REASONS SOLUTION
Cable kinking or breaking.
Drum stops while pedal is
depressed. Restarts when
pedal is re-depressed.
Drum turns in one direc-
tion but not the other.
Ground Fault Circuit Inter-
rupter Trips when machine
is plugged in or when foot
pedal is depressed.
Chart 1 Trouble Shooting
Cable is being forced.
Cable used in incorrect pipe diameter.
Motor switched to reverse.
Cable exposed to acid.
Cable worn out.
Hole in pedal or hose.
Hole in diaphragm switch.
Faulty reverse switch.
Damaged power cord.
Short circuit in motor
Faulty Ground Fault Circuit Interrupter.
.
Do Not Force Cable! Let the cutter do the work.
Use 5/8″cables in 3″to 6″lines, 3/4″cables in 4″to
10″lines,
Use reverse only if cable gets caught in pipe.
Clean and oil cables routinely.
If cable is worn, replace it.
Replace damaged component.
If no problem found with pedal or hose, replace
diaphragm switch.
Replace switch.
Replace cord set.
Take motor to authorized service center.
Replace cord set that includes a Ground Fault
Circuit Interrupter.

K-750 Drain Cleaning Machine
16
Wiring Diagram
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com