1996 Chevrolet C3500 Pickup Brake Service (ONLINE REPAIR MANUALS)

Height Sensing Proportioning Valve

The height sensing proportioning valve must be adjusted whenever the valve and/or linkage is disassembled or removed for service. In addition, adjustment should be checked if excessive front wheel lock-up is experienced with a lower than desired brake application rate when vehicle is at or near maximum GVWR.

• Raise and support vehicle leaving wheels on, and allow axle to hang freely.
• Remove lever retaining nut and disconnect lever from valve shaft, Fig. .
• Rotate valve shaft to permit installation of correct adjustment gauge, Fig. , ensuring that D shape...

Brake System Bleed

1992-95

Electro-Hydraulic Control Unit Brake Pressure Modulator Valve (EHCU/BPMV) Module

The EHCU/BPMV Module should be bled after replacement or if air is trapped in the unit. If bleeding is required, the module must be bled thoroughly before the wheel cylinders and calipers.

There are two bleeders on top of the unit that appear to be normal bleeders, Fig. . These are modulator bleeders and must remain closed when the unit is not pressurized.

The internal bleeders are on either side of EHCU/BPMV module. The valves are used to open the internal passages within the E...

1992

The Rear Wheel Anti-Lock (RWAL) system, Fig. , reduces the occurrence of rear wheel lockup during severe braking by regulating rear hydraulic line pressure. Pressure applied to the rear wheel brakes is regulated by a control valve assembly located under the master cylinder. The control valve consists of a dump valve which releases hydraulic pressure into an accumulator, and an isolation valve which holds rear brake pressure. Operation of the dump valve and isolation valve is controlled by an Electronic Control Unit (ECU) which is mounted next to the master cylinder.

The ECU rec...

Disassemble

• Place accumulator compressor tool No. J-26889 or equivalent, around end of accumulator.
• Install nut onto stud as shown in Fig. , then depress the accumulator with a C-clamp.
• Remove retainer by using a punch.
• Release C-clamp and remove accumulator compressor tool.
• Remove accumulator, O-ring, retainer, plug and spring, Fig. .
• Remove retainer, output pushrod, baffle, piston return spring and retainer.
• Using a suitable saw, cut off eyelet of pedal rod, then remove the boot.
• Remove nut, bracket and bolts, then separate cover from housing.
• Remove piston assembly and seals...

Removal

• Remove caliper assembly as outlined above.
• Remove inboard pad with retainer spring. Dislodge outboard pad and position caliper on the front suspension so the brake hose will not support the weight of the caliper.
• Remove two sleeves from inboard ears of the caliper.
• Remove four rubber bushings from the grooves in each of the caliper ears.

Installation

• Lubricate new sleeves, rubber bushings, bushing grooves and mounting bolt ends with Delco Silicone Lube or equivalent.
• Install new bushings and sleeves in caliper ears. Position the sleeve so that the end toward the pad is flush ...

Removal

• Siphon enough brake fluid out of the master cylinder to bring fluid level to ^1/3 full to avoid fluid overflow when the caliper piston is pushed back into its bore.
• Raise and support vehicle, remove front wheels.
• Using a C-clamp, Fig. , push piston back into its bore.
• Remove two mounting bolts and lift caliper away from disc.

Inspection

Should it become necessary to remove the caliper for installation of new parts, clean all parts in denatured alcohol, wipe dry using lint-free cloths. Using compressed air, blow out drilled passages and holes. Check dust boots for punctures or t...