1995 Chevrolet Astro Brake Service (ONLINE REPAIR MANUALS)

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...

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, on models with hydraulic assist brakes, 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 bra...

Duo-Servo Brakes

Removal

• Raise and support vehicle, then remove tire and wheel assembly.
• Remove brake drum. If brake lining is dragging on brake drum, back off brake adjustment by rotating adjustment screw. Refer to individual truck chapter for procedure. If brake drum is rusted or corroded to axle flange and cannot be removed, lightly tap flange to drum mounting surface with a suitable hammer.
• Using brake spring pliers or equivalent, unhook primary and secondary return springs, Fig. . Observe location of brake parts being removed to aid during installation.
• Remove brake hold-down spri...

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...

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

This braking system, Figs. through , is designed to reduce the occurrence of wheel lock-up during severe braking conditions. To accomplish this function, the system regulates hydraulic brake line pressure by using an Electro-Hydraulic Control Unit (EHCU) module or a Brake Pressure Modulator Valve (BPMV). The EHCU/BPMV module has two types of valves: isolation valves, which maintain separate pressure for each front wheel and combine pressure for the rear wheels, and dump valves, which "dump" pressure to each front wheel separately and rear wheels comb...

Manual Bleed

• If vehicle is equipped with power brakes, remove vacuum reserve by applying brakes several times with engine off.
• Fill master cylinder reservoirs with suitable brake fluid. Be sure to always keep master cylinder reservoirs at least half full during entire bleeding procedure.
• If master cylinder is suspected to have air in the bore, it must be bled first, as follows:
• Disconnect forward brake pipe connection at master cylinder.
• Allow brake fluid to fill master cylinder bore until it begins to flow from forward pipe connector port.
• Connect and tighten forward brake pipe at...