Brake Proportioning/Combination Valve: Service and Repair

REMOVAL OF LSP & BV





1. DISCONNECT SHACKLE NO.2 FROM BRACKET





2. REMOVE LSP & BV ASSEMBLY
(a) Using SST, disconnect the brake tube from the valve body.
SST 09751-36011
(b) Remove the valve bracket mounting bolts and remove the LSP & BV assembly.

DISASSEMBLY OF LSP & BV ASSEMBLY





1. REMOVE VALVE BRACKET
(a) Remove the nut and bolt as shown.
(b) Remove the two nuts, and remove the bracket and set plate from the valve body.





2. DISCONNECT SPRING FROM VALVE
Using a pliers, remove the clip, and remove the spring from the valve.





3. REMOVE SHACKLE NO.1 AND NO.2
Remove the nut and bolt, and then remove the shackle No.1 and No.2, and two plate washers from the load sensing spring assembly.





4. DISASSEMBLE LOAD SENSING SPRING
Disassemble the following parts.
(a) Bushings
(b) Collars
(c) Rubber plates
(d) Load sensing valve boot
(e) Load sensing spring boot


INSPECTION OF LSP & BV





INSPECT VALVE PISTON PIN AND LOAD SENSING SPRING CONTACT SURFACE FOR WEAR
Wear limit: 0.7 mm (0.028 in.)


ASSEMBLY OF LSP & BV





1. ASSEMBLE FOLLOWING PARTS TO LOAD SENSING SPRING
(a) Load sensing valve boot
(b) Load sensing spring boot
(c) Bushings
(d) Rubber plates
(e) Bushings
(f) Collars

HINT: Apply lithium soap base glycol grease to all rubbing areas.





Do not mistake the valve side for the shackle side of the load sensing spring.





2. ASSEMBLE VALVE BODY TO BRACKET
Assemble the valve body to the valve body bracket.
HINT: Finger tighten the valve body mounting nuts.





3. CONNECT VALVE BODY AND NO.1 SHACKLE TO LOAD SENSING SPRING

NOTICE: When connecting the shackle to the load sensing spring with a bolt and nut, install the bolt from the front side of the vehicle.


INSTALLATION OF LSP & BV





1. INSTALL LSP & BV ASSEMBLY TO FRAME
Torque: 29 Nm (300 kgf.cm, 22 ft.lbf.)

2. CONNECT BRAKE TUBE
Using SST, connect the brake tubes. (SST 09751-36011)
Torque: 15 Nm (155 kgf.cm, 11 ft.lbf.)





3. CONNECT SHACKLE NO.2 TO BRACKET
(a) Install shackle No.2 to the load sensing spring.
(b) Connect shackle No.2 to the shackle bracket.
(c) Set dimension A.
Initial set: 78 mm (3.07 in.)

4. SET REAR AXLE LOAD
See Testing and Inspection. Testing and Inspection





5. SET VALVE BODY
(a) When pulling down the load sensing spring, confirm that the valve piston moves down smoothly.
(b) Position the valve body so that the valve piston lightly contacts load sensing spring.
(c) Tighten the valve body mounting nuts.

6. BLEED BRAKE LINE





7. CHECK AND ADJUST LSP & BV FLUID PRESSURE
See Testing and Inspection. Testing and Inspection
8. APPLY SEALANT TO SHACKLE NO.2
Apply sealant to the top portion of the shackle No.2 bolt threads not to lose the upper lock nut.
Sealant: Part No.08833-00070, THREE BOND 1324 or equivalent