HEIGHT SENSING BRAKE PROP. VALVE SETTING PROCEDURE

This bulletin is being published to provide the correct procedure to be followed in setting the height sensing brake proportioning valve on applicable vehicles.

This procedure must be adhered to whenever an existing valve and/or the linkage is disassembled or removed to insure correct valve operation.

1. Raise vehicle, axle must be allowed to hang free (no load condition).

2. Remove nut and disengage lever assembly from valve shaft (Figure 1) .

3. Select appropriate plastic adjustment gage shown in chart below that is available from WDDGM:

ADJUSTMENT GAGE USAGE

PART NUMBER CODE COLOR VEHICLE COMBINATION ------------- ---- ----- -------------------- 14061396 C BLUE K300 LESS RPO G52

14061395 B BLACK C300 LESS RPO G52

14001394 A GREEN CK300 WITH RPO G52

4. Rotate valve shaft to permit installation of plastic adjustment gage. Center "D" shaped hole of gage must seat over "D" shape of the valve shaft and gage tang must be positioned in valve mounting hole (Figure 2).

5. Reinstall lever assembly to the valve shaft utilizing a "C" clamp or channel lock pliers to seat lever nylon bushing to serrations on the valve shaft.

NOTICE: Do not drive the lever onto the shaft using attaching nut. Doing so may result in improper valve setting.

6. Reinstall valve shaft nut and torque to 8-11 N.m (70- 98 in. lbs.).

7. Sever gage tang from body of the adjustment gage to allow the valve assembly to rotate freely (Figure 3).

8. Lower vehicle and test brakes.

Parts indicated in text of bulletin are not currently available. WDDGM will advise dealers through a Sales Information Bulletin when parts are available.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.