C30 Hydro-assist Brakes 1983

[chebby uno ton]

Hello to everyone in chevyland. I am having a problem with my Brakes and it is whupping me. The truck is a 1983 C30 crewcab 3+3 with; 350, t400, 14" F.F. rear. All that stuff works. The truck sat for 3 years "former Owner" and the brakes were shot. This truck is from Fleet Body Engineering and was used as railroad truck in South Carolina. It has 9,000# Gvw with the rear axle for 6,250#,s, 10 springs on the rear. ANYWAY! Brakes????? I have replaced the front calipers and master-cylinder (BENDIX) The pedal goes all the way to the floor with no resestance. It has Hydro-assist and when I had the master cylinder off my girlfriend pushed the pedal down. I have tried to bleed the brkelines master was benchbled before install. Is the hydro unit toast? when i pump the pedal i can hear air pushing through the powersteering resevoir cap. What am I missing. Please and THANKYOU
P.S. Truck is in good shape looks like the railroad kept it up, only poor upkeep is from 2nd owner. Should I replace all lines Blah,blah the hydro unit cost 250.00

[Gooseneck]

You may need to purge the Hydro-Boost system. Fill the power steering pump reservoir to the proper level. Start the engine and cycle steering from stop to stop twice and stop engine. Discharge accumulator by depressing brake pedal several times, then recheck fluid level. The fluid may foam due to air in the system if this occurs let it settle untill fluid level can be checked.

[chebby uno ton]

Thanks for the reply gooseneck! I read that in the manuel and tried it. I just tried it again per your suggestion and all it did was push steering fluid out of the cap when I opened it. Is it possible to have a reverse effect? The pedal goes to the floor like nothin' and comes up real slow. I'm sure that I have air in the brakelines but can't get them to bleed because there is just a faint amount of flow in the lines.

[Gooseneck]

Fluid coming out of the steering pump reservoir is probably because of air still in the system, this will not hinder the bleeding of the brakes. Bleed the brakes with the engine off. Start at the master cylinder then move to combination valve then go to the wheel cylinder farthest from the master cylinder and work up to the closest. The Hydro-Boost unit will stoke the master cylinder with the engine off. You have brakes with your engine off just not power brakes.

[chebby uno ton]

Thanks! Will try
Still trying everything. I got a 12lb beater and think it'l do the trick

[chebby uno ton]

Hey Gooseneck,
I,ve tried to bleed the brakes starting from the master. This is not working. The master will not push anough to bleed. Tried with one hole plugged and jug and hose off of a nipple in the other and also no hose, just finger tip over the hole on the return stroke. The power steering pump just keeps gurgling and the pedal keeps going to the floor with NO resistance. I Bleed the power steering pump again (than shut the motor off) and then get one pedal stroke (still with no resistance) where it will push just a little fluid but than it's back to gurgle and no fluid movement. I have bleed brakes before and never had this problem. I have not bleed these brakes before or a hydro-assist system before. I am at a lose. I bench-bled the master before install and there was no air in it. Plugged the holes while installing it also. PS, The power steering pump also sucks air on the return stroke with both MC holes plugged. One thing that got to me was the need to remove the friggin' fan shroud just to get a wrench on the proportioning block. I like working on my 65 alot better than this future rig. If you think I'm crazy , thats O.K. Thanks for taking the time to help. Some other guy is having the same problem on page three.