Brake Proportioning/Combination Valve: Testing and Inspection

Fig. 31 Type 6, Load Sensing Proportioning Valve Pressure Gauge Test Connection:

WAGON

Prior to performing the following test procedures, park vehicle on a level surface, ensure vehicle is unloaded and at normal curb height.

1. Install suitable gauge set as shown.
2. Bleed the hose and gauge set.

Fig. 33 Type 5, Load Sensing Proportioning Valve Sensor Spring 2WD:

3. On 2WD models, loosen load sensing unit adjusting nuts.

Fig. 34 Type 5, Load Sensing Proportioning Valve Sensor Spring 4WD:

4. On 4WD models, loosen mounting brackets to free operating lever.
5. On all models, while watching pressure gauges, have an assistant depress the brake pedal.
6. Gauge pressure reading should be as follows:
a. When input pressure is 889 psi, output pressure should read 455-526 psi.
b. When input pressure is 1991 psi, output pressure should read 765-879 psi.
c. Output pressure side to side difference should not exceed 57 psi.
7. If pressure readings are as specified proceed to steps 9 or 10 as applicable.
8. If pressure readings are not as specified, replace the proportioning valve and bleed the hydraulic brake system, refer to Brakes and Traction Control/Brakes/Service and Repair.
9. On 2WD models, adjust load sensing spring distance L to 4.10 inch.
10. On 4WD models, adjust load sensing spring distance L to 3.97 inch.
11. On all models, while watching pressure gauges, have an assistant depress the brake pedal.
12. On 2WD models, gauge pressure reading should be as follows:
a. When input pressure is 1991 psi, output pressure should read 1254-1496 psi.
b. Output pressure side to side difference should not exceed 121 psi.
13. On 4WD models, gauge pressure reading should be as follows:
a. When input pressure is 1991 psi, output pressure should read 1249-1491 psi.
b. Output pressure side to side difference should not exceed 121 psi.
14. On all models, if pressure readings are as specified, proceed to steps 16 or 17 as applicable.
15. If pressure readings are not as specified, replace the proportioning valve and bleed the hydraulic brake system, refer to MAINTENANCE PROCEDURES/HYDRAULIC SYSTEM BLEEDING & FLUSHING.
16. On 2WD models, adjust load sensing spring distance L to 3.51-3.59 inch.
17. On 4WD models, adjust load sensing spring distance L to 3.47-3.55 inch.