Jacobs CBRAKE 490 User manual

INSTALLATION MANUAL
Model 490/490A
Installation Manual
ISL98, ISL03, ISL07, ISC07, ISL 2010, ISC 2010,
ISL 2013, L9 2017, L9 2021 Engines

2
INSTALLATION MANUAL FOR 490A
Table of Contents
Section 1: Introduction.............................................................................................2
Housing Identification.........................................................................................2
Engine Identification.............................................................................................2
Special Tools...............................................................................................................3
Automatic Transmissions.................................................................................. 3
Section 2: Engine Preparation......................................................................4-5
Crosshead and Adjusting Screws.............................................................4
Section 3: Engine Brake Housing Installation.................................5-6
Brake Housing Installation..............................................................................5
Slave Piston Adjustment...................................................................................6
Section 4: Electrical System Installation....................................................7
Wiring Installation....................................................................................................7
Section 5: Engine Brake Operation Check.............................................7
Bleed and Operation Check...........................................................................7
Section 6: Engine Brake Maintenance.............................................8 -14
Theory of Operation..............................................................................................8
Exhaust Blowdown...........................................................................................8-9
Control Valve......................................................................................................9-10
Solenoid Valve .......................................................................................................11
Slave Piston Adjusting Screws.................................................................12
Master Piston..........................................................................................................13
Slave Piston.....................................................................................................13-14
SEE DRIVER’S MANUAL FOR PROPER
ENGINE BRAKE DRIVER TECHNIQUES.
THE CBRAKE BY JACOBS®ENGINE BRAKE
IS A VEHICLE SLOWING DEVICE, NOT A
VEHICLE STOPPING DEVICE. IT IS NOT A
SUBSTITUTE FOR THE SERVICE BRAKING
SYSTEM. THE VEHICLE’S SERVICE BRAKES
MUST BE USED TO BRING THE VEHICLE TO
A COMPLETE STOP.
Section 1:
Introduction
Aftermarket Kit
P/N Brake Model Engine Desc.
5708741 490A ISL03 to L9 2021 12VDC Kit
Safety Precautions
The following symbols in this manual signal potentially dan-
gerous conditions to the mechanic or equipment. Read this
manual carefully. Know when these conditions can exist. Then,
take necessary steps to protect personnel as well as equip-
ment.
THIS SYMBOL WARNS OF POSSIBLE PER-
SONAL INJURY.
THIS SYMBOL REFERS TO POSSIBLE
EQUIPMENT DAMAGE.
NOTE:
INDICATES AN OPERATION, PROCEDURE
OR INSTRUCTION THAT IS IMPORTANT FOR
CORRECT SERVICE.
Fuels, electrical equipment, exhaust gases and moving engine
parts present potential hazards that could result in personal
injury. Take care when installing an engine brake. Always use
correct tools and proper procedures as outlined in this manual.
Housing Identification
A nameplate attached to the top surface of the engine brake
housing identifies the model number, part number, front or rear
housing and housing serial number.
For housing part number and other replacement part informa-
tion, refer to Cummins Bulletin No. 3401838, Jacobs Parts
Manual, P/N 026301.
Engine Identification
Prior to engine brake installation, verify that engine is an 2007
ISL engine or newer. The engine identification is on the serial
number plate located on the fuel pump side below the rocker
cover.
Application Notes
Engine Brakes should not be used in combination with an
exhaust brake.
For 24v applications, use front brake housing P/N 5590893
and rear brake housing P/N 5590894.

3
THE 490A BRAKE IS APPROVED FOR USE ON THE
ISC07 AND ISC 2010 ENGINE ONLY. THE 490A
BRAKE IS NOT APPROVED FOR USE ON PRIOR ISC
ENGINE MODELS.
Multiple valve cover options are available. Please contact
your local Cummins dealer for valve cover part numbers for
your specific engine. The valve cover is not included in the
aftermarket kit and should be ordered separately.
Turbocharger Compatibility
When installing an engine brake on the ISL engine a new
turbo actuator is required due to increased backpressure.
Contact your local Cummins dealer for updates regarding the
correct turbo actuator group part number for your engine.
Brake Part
Number Description Engine Brake
Compatible
3945615 Front Oil Fill,
Valve Cover No
3945436 Front Oil Fill,
Valve Cover Ye s
3945834 Rear Oil Fill,
Valve Cover Ye s
3945833 Rear Oil Fill,
Valve Cover No
3945970 Rear Oil Fill,
Valve Cover Ye s
3945971 Front Oil Fill,
Valve Cover Ye s
3945834 No Oil Fill,
Valve Cover Ye s
Special Tools
The following special tools should be available for the instal-
lation:
1. Torque 6 in-lb wrench, Cummins P/N 3376592.
2. Engine Barring tool, Cummins P/N 5299073.
3. Feeler gage/slave piston:
Cummins P/N 3613681, (0.090”)
Cummins P/N 5572956, (0.067”) for L9 2021
Recommended Torque
Values
Mounting Spacer 60 N.m (45 lb-ft.)
Hexagonal Flange Head
cap screw (P/N 3945232) 60 N.m (45 lb-ft.)
Oil Supply Screw 7 N.m (5 lb-ft.)
Hexagonal Flange Head
cap screw (P/N 3927064) 32 N.m (23 lb-ft.)
Cap, Adj Nut 35 N.m (25 lb-ft.)
Nut, Valve Adj 35 N.m (25 lb-ft.)
Nut, D-Lash 35 N.m (25 lb-ft.)
UNLESS OTHERWISE SPECIFIED, THE
TORQUE VALUES LISTED IN THE TEXT
ARE DIRECT VALUES USING NO TORQUE
WRENCH ADAPTERS OR EXTENSIONS.
WHEN ADAPTERS OR EXTENSIONS ARE
USED WITH A TORQUE WRENCH, THE
TORQUE VALUES MUST BE ADJUSTED
FOR THE SPECIFIC TOOLS BEING USED.
FOLLOW THE MANUFACTURER’S RECOM-
MENDED PROCEDURES FOR THE TORQUE
WRENCH AND ADAPTER BEING USED.
Automatic
Transmissions
PRIOR TO INSTALLATION OF THE ENGINE
BRAKE ON VEHICLES WITH AUTOMATIC
TRANSMISSIONS, WE RECOMMEND THAT
THE TRANSMISSION MANUFACTURER
REPRESENTATIVE (DEALER) BE
CONSULTED TO BE SURE OF THE
COMPATIBILITY OF THE ENGINE BRAKE
WITH THE SPECIFIC AUTOMATIC
TRANSMISSION BEING USED.

4
INSTALLATION MANUAL FOR 490A
Section 2: Engine Preparation
Clean engine thoroughly. Remove engine valve cover
and gasket. Retain all parts.
Crosshead and Adjusting Screws
1. Remove the plastic pump drive cover located on
the front of the engine. This will expose the fuel
pump gears and timing marks (Fig. 1).
2. Using the barring tool, Part No. 5299073, rotate
the crankshaft to align the mark on the fuel
pump gear with the top dead center mark on the
gear cover (Fig. 2).
3. Remove Intake rocker lever mounting studs on
cylinders 1 and 4. Replace with new engine
brake oil supply studs. Torque to 60 N•m [45 ft-
lb].
4. Adjust intake lash on cylinders 1, 2, and 4.
NOTE: REFERENCE ENGINE MANUAL FOR INSTRUC-
TION ON SETTING INTAKE VALVE LASH.
5. Remove exhaust rocker lever mounting studs on
Cylinders 1, 3, and 5.
6. Remove exhaust crossheads and replace with
CBrake by Jacobs®Crossheads (Fig. 3).
7. Install new exhaust rocker lever mounting studs
(these will accept the engine brake mounting
bolts). Torque to 60 N•m [45 ft-lb].
8. Remove exhaust rocker adjusting screw locknut
on cylinders 1,3, and 5. Replace lock nuts with
longer lock nut provided in the kit. Do not tighten
at this time.
9. Adjust the exhaust valve lash on cylinders 1, 3,
and 5. Tighten locknut to 25 N•m [20 ft-lb]. In-
stall spherical nut onto long lock nut and torque
to 40 N•m [30 ft-lb].
NOTE: REFERENCE ENGINE MANUAL FOR INSTRUC-
TION ON SETTING EXHAUST VALVE LASH.
10. Check exhaust valve lash on cylinders 1, 3, and
5. Adjustment may have moved when torquing
the spherical nut. Readjust as necessary.
11. Using the engine barring tool, Part No.
5299073, rotate the crankshaft 360 degrees
to align the mark on the fuel pump gear with
the mark on the gear cover that is 180 degrees
away from top dead center (Fig. 4).
12. Adjust intake lash on cylinders 3, 5, and 6.
NOTE: REFERENCE ENGINE MANUAL FOR INSTRUC-
TION ON SETTING EXHAUST VALVE LASH.
FIG. 1
FIG. 2
FIG. 4
FIG. 3

5
13. Remove exhaust rocker lever mounting studs
on cylinders 2, 4, and 6.
14. Remove exhaust crossheads and replace with
CBrake by Jacobs crossheads (Fig. 3).
15. Install new exhaust rocker lever mounting bolts
(these will accept the engine brake mounting
bolts). Torque to 60 N•m [45 ft-lb].
16. Remove exhaust rocker adjusting screw lock-
nut on cylinders 2, 4, and 6. Replace locknuts
with longer lock nut. Do not tighten at this time.
17. Adjust the exhaust valve lash on cylinders 2,
4, and 6. Tighten locknut to 25 N•m [20 ft-lb].
Install spherical nut onto long lock nut and
torque to 40N•m [30 ft-lb].
NOTE: REFERENCE ENGINE MANUAL FOR IN-
STRUCTION ON SETTING EXHAUST VALVE
LASH.
18. Inspect exhaust valve lash on cylinders 2, 4,
and 6. Adjustment may have moved when
torquing the spherical nut. Readjust as neces-
sary.
19. Install six brake mounting spacer studs into
pretapped holes. Torque to 60 N•m [45 ft-lb].
Section 3: Engine
Brake Installation
Engine Brake Installation
1. Make sure the housing adjusting sleeves are
flush with the bottom of the housing or re-
cessed.
2. Apply oil to the oil supply screw o-rings and
slide housings down and into position.
3. Place 3 mounting bolts in the mounting bolt
holes on the slave piston side of the brake
housing (next to slave piston adjusting screws).
Tighten the three bolts to 7 N•m [5 ft- lb] (Fig.
5).
4. Screw down the three housing adjusting
sleeves until they just make contact with the
rocker arm pedestals.
5. Place the 3 remaining mounting bolts with
hardened washers into the adjusting sleeves
and hand tighten. Brake should be flat on
rocker arm pedestal and spacer. Torque the 6
mounting bolts to 32 N•m [23 ft-lb].
6. Install electrical harness from each engine
brake solenoid to the spacer pass-through
connector.
FIG. 5
For ISL98: Spacer Installation
1. Clean rocker housing. Apply sealant to spacer.
Place spacer on position.
2. Hand start the five spacer bolts (these will
accept the cover screws). Starting from the
center and proceeding outward on both sides
torque the bolts to 32 N•m [23 ft-lb].

6
INSTALLATION MANUAL FOR 490A
Slave Piston Adjustment
NOTE: ADJUST THE SLAVE PISTON CLEARANCE
WITH THE ENGINE STOPPED AND COLD.
STABILIZED WATER TEMPERATURE OF
140° F. (60° C.) OR BELOW. EXHAUST
VALVES, ON THE CYLINDER TO BE ADJUST-
ED, MUST BE IN THE CLOSED POSITION.
1. The TDC mark on the fuel pump gear should
already be at 180 degrees from TDC. The
mark on the fuel pump gear should be in the 6
o’clock position on the gear cover. In this posi-
tion the engine brake slave lash on cylinders 2,
4, and 6 can be set. (Fig. 6)
2. Insert the appropriate brake lash feeler gauge
(P/N 3163681(0.090”) or P/N 5572956
(0.067” for L9 2021)) between the brake slave
piston and exhaust head pin on cylinder one.
(Fig. 7, 8)
If brake lash is set improperly, engine damage
may occur.
3. Using the 6 in-lb torque wrench, P/N
3376592, tighten the adjusting screw until the
torque wrench “clicks” or if not using a torque
wrench, until drag is felt on the feeler gage.
4. Using two wrenches, hold the adjusting screw
and tighten the locknut to 35 N•m [26 ft-lb]. If
a light drag is not felt on the feeler gage read-
just as necessary.
5. Repeat steps 2-4 for cylinders 4 and 6.
6. Using the barring tool, Part No. 5299073,
rotate the crankshaft to align the mark on the
fuel pump gear with the top dead center mark
on the gear cover (12 o’clock) (Fig 9).
7. When the engine is in the top dead center
position, Slave Piston Lash can be set on cylin-
ders 1, 3, and 5.
8. Repeat steps 2-4 for cylinders 1, 3, and 5. (Fig.
7, 8)
9. Install the plastic drive cover located on the
front of the engine.
FIG. 8
FIG. 9
FIG. 7
FIG. 6

7
Section 4: Electrical Installation
ISL Wiring Installation
Refer to Cummins service manual or contact your local Cummins service center for wiring installation infor-
mation.
Section 5: Brake Operation Check
The CBrake by Jacobs engine installation is now
complete. The following procedures and adjust-
ments should be made.
Recheck the housing installation. Be certain no for-
eign objects have been left behind and all correct
clearance requirements have been met.
Bleed and Operation
Check
WEAR EYE PROTECTION AND DO NOT
EXPOSE YOUR FACE OVER ENGINE AREA.
TAKE PRECAUTIONS TO PREVENT OIL
LEAKAGE DOWN ON THE ENGINE. WHEN
ENGINE IS RUNNING AND VALVE COVERS
ARE REMOVED, OIL SPLASHING IN THE
ENGINE BRAKE AREA COULD CAUSE PER-
SONAL INJURY.
1. Assure that the control wires are connected to the termi-
nal assemblies in engine brake spacers.
2. Bleed brake housings and check their operation. Start
engine and allow to run 5 to 10 minutes, or until the en-
gine has reach proper operating temperature. Accelerate
engine to approximately 1800 RPM and release throttle.
Both solenoid valves should operate.
3. Repeat this procedure several times to bleed brake hous-
ings for immediate operation.
FIG. 10
Replace Rocker Lever Cover
1. Install the new gasket and cover on the spacer. Tighten
the cover capscrews starting from the center and working
out to 12 N•m [9 ft-lb]. (See Fig. 10)

8
INSTALLATION MANUAL FOR 490A
Section 6: Brake Maintenance
Theory of Operation
Energizing the engine brake effectively converts
a power-producing diesel engine into a pow-
er-absorbing air compressor. This is accomplished
through motion transfer using a master/slave
piston arrangement which opens cylinder exhaust
valves near the top of the normal compression
stroke, releasing the compressed cylinder charge
to exhaust.
The blowdown of compressed air to atmospher-
ic pressure prevents the return of energy to the
engine piston on the expansion stroke. The effect
is a net energy loss, since the work done in com-
pressing the cylinder charge is not returned during
the expansion process.
Exhaust Blowdown
Referring to Fig. 11, exhaust blowdown occurs as
follows:
1. The energized solenoid valve permits engine
lube oil to flow under pressure through the
control valve to both the master piston and the
slave piston.
2. Oil pressure causes the master piston to move
down, coming to rest on the exhaust rocker
arm adjusting screw.
3. The exhaust rocker arm adjusting screw begins
upward travel (as in normal exhaust cycle),
forcing the master piston upward and direct-
ing high pressure oil to the slave piston. The
ball check valve in the control valve imprisons
high-pressure oil in the master/slave piston
system.
4. The slave piston, under the influence of the
high-pressure oil moves down, momentarily
opens one exhaust valve while the engine
piston is near its top dead-center position, re-
leasing compressed cylinder air to the exhaust
manifold.
5. Compressed air escapes out to the atmo-
sphere, completing a compression braking
cycle.
FIG. 11
OIL IN
SOLENOID
VALVE
CONTROL
VALVE
ADJUSTING
SCREW
HIGH
PRESSURE
OIL
MASTER
PISTON
EXHAUST
PUSHROD
SLAVE
PISTON
BALL
CHECK
VALVE
EXHAUST VALVES
EXHAUST
ROCKER
LEVER
GUIDELESS
CROSSHEAD
LOW
PRESSURE
OIL

9
FIG. 14
The CBrake by Jacobs is a relatively trouble-free
device. However, inspections and routine mainte-
nance will need to be made from time to time. Use
the following procedures to keep the engine brake
in top condition.
This section will cover how to properly remove,
clean and reinstall engine brake components. Use
an OSHA-approved cleaning solvent when wash-
ing parts. Be sure to coat parts with clean engine
oil when reinstalling them.
NEVER REMOVE ANY ENGINE BRAKE
COMPONENT WITH ENGINE RUNNING.
PERSONAL INJURY MAY RESULT.
NOTE: FIG. 12 IS ACTUAL ISL03 BRAKE. FIG. 13-26
ARE TYPICAL BRAKE COMPONENTS AND NOT
SPECIFIC TO 490A.
Control Valve
REMOVE CONTROL VALVE COVERS
CAREFULLY. CONTROL VALVE COVERS ARE
UNDER LOAD FROM THE CONTROL VALVE
SPRINGS. REMOVE WITH CARE TO AVOID
PERSONAL INJURY.
1. Apply pressure on the control valve cover and
remove retaining ring using retaining ring pliers
(see Fig. 13).
2. Slowly remove cover until spring pressure
ceases, then remove the control valve springs
and collar (see Fig. 14).
FIG. 13
FIG. 12

10
INSTALLATION MANUAL FOR 490A
3. Using needle-nose pliers or a magnet, remove
the control valve (see Fig. 15).
4. Wash the control valve with approved cleaning
solvent. Push a wire through the hole in the
base of the valve to ensure that the ball check
is free. The ball should lift with light pressure
on the wire. If the ball is stuck or there is no
spring pressure, replace the control valve. Dry
the valve with compressed air and wipe clean
with a paper towel.
5. Thoroughly clean the control valve bore in the
housing using clean paper towels.
6. Dip the control valve in clean lube oil. Drop the
valve into its bore. If binding occurs, the control
valve should be replaced.
7. Reassemble the parts, reversing the removal
procedure. Be sure retaining ring ears are posi-
tioned opposite the oil drain slot in the housing
(see Fig. 16).
NOTE:
BE SURE THE CONTROL VALVE COLLAR
IS INSTALLED WITH THE LONGER SLEEVE
AREA UP (SEE BELOW). IF THE COLLAR IS
INSTALLED UPSIDE DOWN, THIS BRAKE
CYLINDER WILL NOT OPERATE.
FIG. 15
FIG. 16
UP

11
Solenoid Valve
1. Disconnect the solenoid harness. Using a 3/4”
socket and extension, unscrew the solenoid
valve (see Fig. 17).
DO NOT DISASSEMBLE OR TAMPER WITH
THE SOLENOID VALVE. ENGINE DAMAGE
COULD RESULT.
2. Remove and discard the rubber seal rings (Fig.
18). If the lower ring stays in the bottom of the
housing solenoid bore, remove with a seal pick.
3. Wash out the solenoid valve with approved
cleaning solvent. Use a brush to clean the
oil screen. Clean and dry the valve with com-
pressed air. Replace oil screen, if necessary.
4. Clean out the solenoid valve bore in the hous-
ing. Use clean paper towels. Never use rags, as
they may leave lint and residue which can plug
the oil passageways.
5. Reinstall the solenoid using new seal rings.
Seat lower seal ring (ISL only) in the base of
the solenoid valve bore. Wipe clean lube oil into
and around the bore. Place upper and center
seal rings on the solenoid valve body.
6. Be sure the seals are seated properly and
carefully and screw the solenoid into the hous-
ing without unseating the seals. Torque the
valve to 20 N•m [15 lb.-ft] (see Fig. 19).
FIG. 19
FIG. 18
FIG. 17
Note: 490A only has two seal rings.
UPPER SEAL
CENTER SEAL
LOWER SEAL

12
INSTALLATION MANUAL FOR 490A
Slave Piston Adjusting
Screws (D Lash)
Loosen slave piston adjusting screw locknut and
remove adjusting screw from housing (Fig. 20).
Clean adjusting screw in an approved cleaning
solvent.
Inspect the slave piston adjusting screw (D Lash).
The plunger should protrude from the bottom
of the screw, and move freely (Fig. 21). Be sure
the retaining ring is fully engaged in its groove.
Replace the entire screw assembly any defect is
found.
DO NOT READJUST OR TAMPER WITH THE
ADJUSTING SCREW ASSEMBLY. ENGINE
DAMAGE COULD RESULT.
FIG. 21
FIG. 20
SLIDE PLUNGER

13
Master Piston
Remove the button-head screw, washer and mas-
ter piston spring from bottom of housing.
Remove the master piston from its bore using nee-
dle-nose pliers. If binding occurs, check for burrs or
contaminants in the lube oil. Clean in an approved
cleaning solvent (Fig. 22).
NOTE:
DO NOT ATTEMPT TO REMOVE THE MAS-
TER PISTON WITHOUT FIRST REMOVING
THE FLAT SPRING. BENDING THE SPRING
BACK TOO FAR CAN DISTORT THE SPRING
AND WOULD NEED TO BE REPLACED.
Inspect the hard face surface. A pitted, chipped,
cracked or galled piston should be replaced. If the
hard facing is damaged, inspect the corresponding
rocker arm adjusting screws for excessive wear or
pitting. Replace if damaged.
Reassemble in reverse order. When tightening the
capscrew, make certain the two spring tabs do not
interfere with the sides of the master piston center
raised portion (see Fig. 23). Torque the capscrew
to 12 N•m [9ft- lb].
NOTE:
THE TABS SHOULD BE EQUALLY SPACED
FROM THE RAISED PISTON AREA.
Slave Piston
WEAR SAFETY GLASSES. REMOVE SLAVE
PISTON CAREFULLY. THE SLAVE PISTON IS
RETAINED BY SPRINGS THAT ARE UNDER
HEAVY COMPRESSION. IF THE FOLLOWING
INSTRUCTIONS ARE NOT FOLLOWED AND
PROPER TOOLS NOT USED, THE SPRING
COULD BE DISCHARGED WITH ENOUGH
FORCE TO CAUSE PERSONAL INJURY.
Remove the locknut on the slave piston adjusting
screw. Back out the adjusting screw until the slave
piston is fully retracted (screw is loose).
Use the slave piston removal tool and the following
procedure to remove and replace the slave piston:
1. Place the hole in the clamp bracket over the
slave piston adjusting screw (Fig. 24).
2. While holding the tool in position, screw the
holder down over the slave piston stem until
the retainer is contacted.
FIG. 23
FIG. 22
FIG. 24

14
INSTALLATION MANUAL FOR 490A
3. Turn the handle slowly until the retainer is
depressed, about 1/32” (1 mm), relieving pres-
sure against the retaining ring.
4. Remove the retaining ring using retaining ring
pliers. Back out the holder until the springs are
loose. Remove the tool. (see Fig. 25)
5. Remove the retainer, spring and slave piston.
Check for nicks or burrs that could cause bind-
ing. (see Fig. 26)
6. Clean the piston in an approved cleaning
solvent. Run a small wire through any holes.
Replace the piston if the ground surface on the
outside diameter is scratched or scored.
NOTE:
BE SURE ALL COMPONENTS ARE
REASSEMBLED IN CORRECT ORDER.
7. Reassemble in reverse order.
8. Use the removal tool to compress the slave
piston and springs down until the retainer is
about 1/32” (1 mm) below the retaining ring
groove (see Fig. 25).
9. Slide the retaining ring over the threaded rod
of the removal tool and reinstall the retaining
ring in its groove. Be sure the retaining ring is
fully engaged in the groove.
10. Remove the tool slowly to ensure proper seat-
ing of retaining ring.
11. Assemble the locknut; do not tighten.
FIG. 25
FIG. 26

15
Notes:

JACOBS VEHICLE SYSTEMS, INC. I 22 EAST DUDLEY TOWN ROAD BLOOMFIELD, CT USA 06002 I P/N 00-026302 REV E 12/2021 I ©2021 JACOBS VEHICLE SYSTEMS, INC.
CELECT™ is a trademark of Cummins Inc.
CBrake by Jacobs®is a trademark of Cummins Inc. and Jacobs Vehicle Systems, Inc.
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