STO M-8 Troubleshooting guide

Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone]
Operation and Maintenance Instructions
Sto M-8 Spray Pump
For assistance, please call:
StoMachine Technology HelpLine
[phone]
www.stocorp.com

Sto M-8 Spray Pump Operation and Maintenance Instructions
________________________________________________________________________________________________________________________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 2 of 15
Table of Contents
Performance............................................................................................................... 3
Advantages................................................................................................................. 4
1. Use......................................................................................................................... 5
2. Delivery Condition................................................................................................... 5
3. Description and Function of Including Operating Components............................... 5
3.1 Operation of Control Panel ............................................................................... 6
3.2 Forward ............................................................................................................ 6
3.3 Backward.......................................................................................................... 6
3.4 Overload Protection.......................................................................................... 7
3.5 Control Safety................................................................................................... 7
3.6 Manual Operation............................................................................................. 7
3.7 Remote Control Use......................................................................................... 8
3.8 Regulating Operating Pressure......................................................................... 8
4. Operation of Pump ………….............................................................................9-10
5. Clean-up of Pump................................................................................................. 11
6. How to Change Delivery Washer and Membranes............................................... 12
7. Trouble Shooting .................................................................................................. 13
8. Technical Recommendation ................................................................................. 14
8.1 Service Manual............................................................................................... 14
8.2 Lubricant Recommendation............................................................................ 14
9. Technical Data...................................................................................................... 15
10. Worn Parts.......................................................................................................... 15
10.1 Membranes................................................................................................... 15
10.2 Conveying Disc............................................................................................. 15
10.3 O-Rings ........................................................................................................ 15

Sto M-8 Spray Pump Operation and Maintenance Instructions
________________________________________________________________________________________________________________________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 3 of 15
Performance
The Sto M-8 Spray Pump is a new type of pump technology, protected with three
different patents. This new technology enables a wide range of Sto products that are
capable of being used for spray or roller applications.
The peristaltic technology (similar as a milling operation) conveys the material by
massaging or pushing.
F
Delivery Washer
Material Entry
Material Exit
Rubber Diaphragm

Sto M-8 Spray Pump Operation and Maintenance Instructions
________________________________________________________________________________________________________________________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 4 of 15
Advantages
The conveying of material is smooth and there is no damage to the products.
There is low pressure built-up in the material hose and a wide range of products can be
sprayed or roller applied through the Sto M-8 Spray Pump.
The result: 30 to 40 % less wear on parts due to the smoother conveying!
20 to 50 % savings in labor!
Detailed Advantages:
-Low pressure build-up in hoses
-No damage to products
ÇGentle treatment of materials
-Less worn parts
-Safe to run dry
ÇResult: dependable
-Light and handy (approx. 57 lbs)
-Operates with 110 V
-Quiet
-Perfect spray appearance
Proven and tested for every construction site!!

Sto M-8 Spray Pump Operation and Maintenance Instructions
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 5 of 15
1. Use
The Sto M-8 Spray Pump conveys liquids, aggregated materials up to 2mm, sand
finishes, coatings, concrete, and repair products. When using products for the first time,
we recommend applying on a small test area. We do not recommend the use of R
(rilled) finishes to be spray applied.
2. Delivery Condition
Sto M-8 Spray Pump contains:
Motor with flanged pump housing
Material hopper
24 mm wrench
Start up kit and/or spare parts kit
3. Description and Function of Operating Components
All operating components are located on one side of
the pump housing.

Sto M-8 Spray Pump Operation and Maintenance Instructions
_______________________________________________________________________________________________________________ _________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 6 of 15
3.1 Operating the Control Panel
“OFF“ – M-8 is switched off
3.2 Forward
“FWD“ -- M-8 is switched on (Forward) to pump
material through hose.
3.3 Backward
“REV“ – M-8 runs backwards. Necessary to clean
pump or when blockage occurs in material hose.
When pump is run in REV (reverse) this releaves
pressure from the material hose to allow for safe
removal of hoses.

Sto M-8 Spray Pump Operation and Maintenance Instructions
_______________________________________________________________________________________________________________ _________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 7 of 15
3.4 Overload Protection
Overload Protection:
Automatic overload protection protects motor and
operator.
3.5 Control Safety
24 Volt Circuit Breaker for Remote Control:
Defective remote control cable (short-circuit) engages
circuit breaker automatically.
3.6 Manual Operation
To manually or remotely operate the M-8 for running
or cleaning, either the remote cable or the dummy
plug needs to be connected.

Sto M-8 Spray Pump Operation and Maintenance Instructions
_______________________________________________________________________________________________________________ _________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 8 of 15
3.7 Remote Control Use
Remove the dummy plug and connect the remote
control cable. Set M-8 in FWD position. You will now
have control of the pump at the remote on/off switch
located near the nozzle.
3.8 Regulating Operating Pressure
Operating pressure is adjustable. 1 on scale = lowest
pressure, 13 on scale = highest pressure.
The amount of pressure determines the flow of
material.

Sto M-8 Spray Pump Operation and Maintenance Instructions
_______________________________________________________________________________________________________________ _________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 9 of 15
4. Pump Operation
Check voltage before starting. Pump works with 110
Volts at 60 hz.
Use a 12 gauge extension cord for best results.
Hopper
Connect hopper to M-8 coupling on top of the pump.
Twist and lock into place.
Use for spraying aggregated finishes, coatings and
other Sto products.
Siphon Hose
Not available in the US.
Contact StoMachine Technology HelpLine at (888)
522-0184 for more information.

Sto M-8 Spray Pump Operation and Maintenance Instructions
________________________________________________________________________________________________________________________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 10 of 15
Connect material hose to M-8. Connect air supply to spray nozzle. Material hoses must
be primed prior to spraying Sto products. Contact StoMachine HelpLine for proper hose
lubricant to be used to prime hose.
Fill material hopper first, turn switch on lowest
pressure level (1). Before turning on pump, make
sure the spray nozzle is open. Turn on the pump.
Note: To operate pump the dummy plug or the
remote cable must be connected.
If M-8 is not pumping material turn pressure switch to next setting, moving only one
setting at a time, until desired material flow is achieved.
Important: Do not stress pump and hoses. Please
use only as much pressure as needed.
Pump aggregated finishes, coatings and other Sto products at maximum flow rate with
lowest possible pressure. To achieve best spray appearance please try first on a small
area.
Float all finishes; some coatings require backrolling.

Sto M-8 Spray Pump Operation and Maintenance Instructions
________________________________________________________________________________________________________________________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 11 of 15
5. Cleaning of Pump
Pump all material out of hopper; stop M-8 pump.
Disconnect hopper and clean. Place hopper onto
M-8 and flush hoses with water until water comes out
of spray nozzle. Stop pumping and clean hoses,
machine, spray nozzle and orifice.
Note: Ensure that hopper is cleaned first prior to
cleaning pump and hose.
You will find a 24 mm wrench on the right side of
pump housing.
After cleaning we recommend to check M-8 for worn
parts (see section 7, page 13).
To clean hoses: Connect material hose to water
hose, place a sponge ball in material hose and flush
with water. Repeat until water is clear.

Sto M-8 Spray Pump Operation and Maintenance Instructions
________________________________________________________________________________________________________________________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 12 of 15
6. How to Change Delivery Washer and Membranes
Remove cap nut and flat washer at the front side of
pump, 24 mm wrench provided.
Take off connection plate (flange).
Please make sure that the two O rings do not fall out
while taking off connection plate.
Remove delivery washer.
Carefully lift and pull out rubber diaphragm with screw
driver. Install new parts in reverse order.
Note: Ensure that the fingers are lubricated between
the two rubber diaphragms.

Sto M-8 Spray Pump Operation and Maintenance Instructions
_______________________________________________________________________________________________________________ _________
StoCorp.3800CampCreekParkway,Bldg1400,Ste120 Atlanta,GA30331
Phone[phone] Fax[phone] Page13of15
7. Trouble Shooting
M-8 does not pump: Possible cause:
”Cap nut that secures flange is not tightened
enough. There should be no gap between
flange and housing.
”Pressure switch to select pressure is adjusted
too low.
”Rubber diaphragm or delivery washer are
defective.
”O-rings at connection plate are missing.
”Flat washer was placed inside flange instead of
outside under cap nut.
Pumping power fades: Possible cause:
”Plastic delivery washer is worn and has to be
replaced.
”Check rubber diaphragm for cracks and replace
if necessary.
Overload protection shuts off pump:
”Material consistency is too thick
”Power supply fails:
12 ga. cord required
24 V Safety control:
”When remote control cable is defective
îshort-circuit.
”Repair the short and reset circuit breaker.

Sto M-8 Spray Pump Operation and Maintenance Instructions
_______________________________________________________________________________________________________________ _________
StoCorp.3800CampCreekParkway,Bldg1400,Ste120 Atlanta,GA30331
Phone[phone] Fax[phone] Page14of15
8. Technical Recommendation
8.1 Service Manual
Check rubber diaphragm and delivery washer for
damage and cracks after daily cleaning routine.
Exchange rubber diaphragm and delivery washer as
described, if necessary. Please check all electrical
plugs and power supply before starting.
Replace damaged plugs and cables. Replacements
and changes are only to be conducted by trained
operators.
8.2 Lubricant Recommendation
Transmission is filled with oil CLP ISO VG
220 and will last a life-time. It is not necessary to
exchange this oil.
Contact StoMachine Technology HelpLine at
[phone] with ANY questions regarding the
operation or maintenance of the Sto M-8 Spray
Pump.

Sto M-8 Spray Pump Operation and Maintenance Instructions
_______________________________________________________________________________________________________________ _________
Sto Corp. 3800 Camp Creek Parkway, Bldg 1400, Ste 120 Atlanta, GA 30331
Phone [phone] Fax [phone] Page 15 of 15
9. Technical Data
Technical Data
Type of Actuation: Direct Drive: ZV-belt: ¸
Actuation: Alternating current motor: ZFrequency converter: ¸
Current, frequency: 110 volts, 60 hz
Operation Data
Actuation Revolution: 220 RPM
Operation Temperature: Ca. 68 °F (20 °C)
Transmission: 1 : 6.3
Depression Torque: 11.5 ft-lbs (15.6 Nm)
10. Wear Parts
10.1 Membranes
Article No. M900872 - Rubber Diaphragm 3 mm
2 pieces
10.2 Conveyer Disc
Article No. M900820 - Delivery Washer
1 piece
10.3 O-Rings
Article No. M900805 - O-Rings
1 piece