1997 Chevy Silverado Z71 350 5.7L V8 200k miles

I'll just get right into the story.

I'll appreciate it very much if you actually take your time and read all this and try to help me out. Thank you.

Checked my brake fluid one time. Put the cover back on. Checked it later to find out the seal wasn't sealed right. (I now know to put the seal on the lid THEN put it on the master cylinder haha.)

I was having some problems with my brakes. Stiff pedal sometimes, then it'd be okay. So I got sick of the problem and my dad seemed to think it was the brake booster. So we went the the junkyard and pulled a booster and master cylinder (PITA), paid $75 and went on our way.

After we bought it my dad was saying how we should try to do a brake bleed just in case. So we did a brake bleed (it needed one, the fluid was very dirty) and it fixed the problem it seemed. Well that lasted roughly a week and the problem started to come back.

So I decided to bleed the brakes again. The brake fluid was just a little dirty, but I figured I'd try it. No change this time. The brake pedal is still very stiff especially at first start up. Sometimes I can barely brake unless I push really hard on the stiff pedal.

So before I go spend a bunch of money on (a) part(s), what do you guys think? Let me know if I need to go further into detail about something.

BTW, the booster holds vacuum and the check valve is working.

Thanks again!

 

Bump!

 

Kohen, I found what looks to be a good checklist for your hard pedal symptom:

HARD PEDAL (Excessive pedal pressure needed to stop vehicle - pedal is high - but hard - on first pump.

• Vacuum hose collapsed (can be internal and not show on outside). Replace vacuum hose.
• Loose or plugged vacuum fittings - repair or tighten fittings.
• Cracked or broken plastic hub - replace unit.
• Engine does not develop enough vacuum - tune up required.
• Faulty vacuum check valve - replace faulty check valve.
• Kinked, collapsed, dented or clogged hydraulic lnes, hoses or connections - repair or replace faulty part.
• Swollen master cylinder cups (by fluid contamination) - flush system with alcohol to remove contaminated fluid and replace cylinder.
• Restricted air filter or manual brake boot is installed (boot without air inlet holes) - replace air filter or boot.
• Damaged diaphragm - replace unit.
• Damaged valve rod and plunger assembly - replace unit.
• Binding pedal linkage - free up and lubricate.

I would check the things that could be fixed w/o replacing the master cylinder and booster first and if nothing found, install your new-used parts.

Gerald

 

I've tried/done most of these. But thanks for this great list! I'll take a look into the rest. Thank you

 

Well a guy on an other forum told me: "to check the booster:

-with the engine off, depressed the brake pedal repeatedly to deplete the vacuum reserve

-keep the pedal depressed and start the engine

with a properly operating booster, the pedal should sink deeper as the vacuum assists brake apply. A faulty booster won't sink deeper."

So I did that and the problem seems to be the booster because I started it and the pedal didn't move. Hopefully that's the only problem.

If anyone else wants to chime in and say something, feel free.