Height Sensing Proportioning Valve - Removal

NO: 05-04-98

GROUP: Brakes

DATE: Jun. 12, 1998

SUBJECT:

Height Sensing Proportioning
Valve Removal

MODELS:

1997 - 1999 (BR/BE) Ram Trucks

NOTE:
THIS BULLETIN APPLIES TO 2500 SERIES 4X4 VEHICLES THAT ARE CONTINUOUSLY OPERATED AT 75% OR GREATER GVW AND HAVE HAD THEIR REAR SUSPENSION ALTERED TO INCREASE RIDE HEIGHT AND ARE BUILT AFTER THE FOLLOWING DATES.

LAGO ALBERTO ASSEMBLY PLANT (11TH POSITION OF VIN = M) -
APRIL 3, 1997 (MDH 0403XX)
ST. LOUIS NORTH ASSEMBLY PLANT (11TH POSITION OF VIN = J) -
MARCH 17, 1997 (MDH 0317XX)
SALTILLIO ASSEMBLY PLANT (11TH POSITION OF VIN = G) - APRIL 3, 1997 (MDH 0403XX)

DISCUSSION:

The vehicles listed on this bulletin are equipped with a rear height sensing proportioning valve that adjusts brake pressure to the rear brakes based upon the distance between the vehicle's frame and rear axle.

In situations in which the vehicle is operated continuously at 75% or greater of GVW and the vehicle's rear suspension has been altered, removal of the rear height sensing proportioning valve may be necessary to help prolong the front brake pad life and provide optimum braking performance. The following Repair Procedure has been provided for the removal of the rear height sensing proportioning valve.

CAUTION:
THIS PROCEDURE SHOULD ONLY BE PERFORMED ON 2500 SERIES 4X4 VEHICLES THAT ARE CONTINUOUSLY OPERATED AT 75% OR GREATER GVW AND HAVE HAD THEIR REAR SUSPENSION ALTERED.

PARTS REQUIRED:

1 52009575AB Hose, Brake

REPAIR PROCEDURE:

This bulletin involves replacing the rear height sensing proportioning valve with a brake hose.

1. Raise and support the vehicle.





2. Remove the link from the axle bracket (Figure 1).





3. Remove the brake line adapter from the rear height sensing proportioning valve bracket (Figure 2).

4. Remove the hose from the axle.

5. Remove the two nuts from the frame mounting bracket and remove the valve assembly.

6. Attach new brake hose p/n 52009575AB to the rear axle and connect the hose to the brake lines.

7. Attach the new brake hose to the brake line bracket on the frame rail.

8. Connect the brake line at the frame to the new hose.

9. Bleed the brake system. Refer to the appropriate Service Manual, Group 5 for information regarding proper brake bleeding procedures.

POLICY: Information Only