1994 Chevrolet K2500 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...

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 ...

Master Cylinder

Some vehicles use a conventional tandem master cylinder with two hydraulic pistons operating inline. The primary piston controls the front brake system and the secondary piston controls the rear brake system.

Other models use a master cylinder that operates the same as the conventional master cylinder, but also incorporates a quick take-up feature in the rear chamber to reduce excessive pedal travel which may result from increased fluid displacement required to move the low drag caliper piston out against the rotor.

The quick take-up uses a spring-loaded ball check valv...

Accessing Diagnostic Trouble Codes

Except S & T Series w/VCM & VCM-A

1992-95

Diagnostic trouble codes can be read using a TECH 1 scan tool or by jumping terminal "H" to terminal "A" of the Assembly Line Diagnostic Link (ALDL) connector, Fig. , and counting the Anti-Lock lamp flashes. The terminals must be jumped for a few seconds before the diagnostic trouble codes will begin to flash.

1996

Diagnostic trouble codes can only be read by connecting a suitable scan tool to the Data Link Connector (DLC), Fig. . Follow the instructions provided by the scan tool manufacturer.

S & T Seri...

Accessing Diagnostic Trouble Codes

This system has a sophisticated diagnosis system designed to identify any system fault as specifically as possible, including intermittent faults. There are many diagnostic trouble codes used by the system. Each input and output to the system can be monitored with a suitable bi-directional scan tool; monitoring inputs and outputs allows for fault confirmation and repair verification. The scan tool can also be used to manually control components and perform functional tests.

• Connect a TECH 1 or equivalent scan tool to the diagnostic connector,...

Certain general service procedures apply, regardless of whether the brakes are vacuum or hydraulically assisted. Only top quality, clean brake fluid should be used. More seals and valves are used with power brake systems than with ordinary brakes, so an inferior brake fluid will do much more damage. For the same reason, be sure all dirt is kept out of the system. Additionally, care must be taken not to mix the fluids of the booster hydraulic system and brake hydraulic system as the fluids are not compatible.

If the power unit fails, the brakes will still operate, as the conventio...