Front Brakes - Premature Lining Wear/Hard Pedal

89ford36

Article No. 89-25-16

^ BRAKES - FRONT - PREMATURE LINING WEAR

^ BRAKES - REAR HEIGHT SENSING PROPORTIONING VALVE - INOPERATIVE DUE TO SUSPENSION MODIFICATION

LIGHT TRUCK: 1985-86 F-250, F-350 1985-89 E-250, E-350


ISSUE: High brake pedal efforts or increased front brake lining wear may be caused by aftermarket suspension modifications. The modified suspension may affect the performance of the height sensing proportioning valve.

Figure 2:

Figure 3:

ACTION: Inspect the truck to determine if the suspension has been modified. Compare the rear suspension (springs) to the suspension specifications shown in the Light Truck Facts Book and the spring codes listed on the vehicle certification label, Figure 2 and 3. If the suspension has been modified or will be modified, use the following procedure. If the suspension has not been modified, replace the height sensing proportioning valve as outlined in TSB 88-12-20.

Figure 1:

1. Remove the nut from the valve shaft and remove the leading arm of the linkage assembly, Figure 1. Save the nut.

2. Remove the two (2) nuts from the differential housing bolts and remove the linkage bracket, Figure 1.

3. Return the linkage to the customer.

Figure 4:

4. Rotate the valve shaft one (1) full turn in either direction. Position the shaft with the flat at the bottom and parallel with the ground, Figure 3.

Figure 5:

5. Rotate the valve shaft counter-clockwise 90~ so that the flat of the shaft is vertical, Figure 5.

Figure 6:

6. Place the valve shaft positioner, (E9TZ-2W125-A) over the valve shaft as shown in Figure 6. Make sure the shaft flat fits into the "D"-slot of the positioner and that the shroud is fully seated over the valve casting.

7. Re-install the nut saved in Step 1 on the valve shaft. Hold the shaft positioner and tighten the nut to a torque of 8-10 lb.ft. (11-14 N-m).




8. Install an "Authorized Modification" decal on the brake booster listing the modification as follows: "HSPV REAR BRAKE OPERATION MODIFIED".

Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.

PART NUMBER PART NAME CLASS

E9TZ-2W125-A Valve Shaft Positioner C

OTHER APPLICABLE ARTICLES: 88-12-20
WARRANTY STATUS: Eligible Under Basic Warranty Coverage
OPERATION DESCRIPTION TIME
892516A Modify Height Sensing 0.6 Hr.
Valve
DEALER CODING
BASIC PART NO. CONDITION CODE
2B547 53
OASIS CODES: 3050, 3051