Hi All,

I just replaced the front brakes on my wifes 87 today. I used a c clamp to close the piston on the caliper. The pedal was to the floor and the brake light is on. I tried to bleed the brakes and I can get the fluid to flow to the front calipers. It seems like the master cylinder is air locked and I cant get a pedal. Single reservoir on master cylinder and its overfull. Do I have to reset the ABS system or something. I have done brake jobs all my life and never had this problem. Does anyone know what the problem is? Thanks.


Joe-Flash man

don't worry about the ABS... it's more than likely in the master.

I would remove the lines on the master and see if that releases it. Also, you might want to remove the master completely and re-bench bleed it.

I just read on another corvette forum that all the calipers have check valves in the bleeders and the check valves get stuck and you cant bleed them. Is that true? I also had a hard time bleeding the brakes on my 86. I could not get the pedal to go all the way down, when I opened the bleeder and very little brake fluid came out. Check this out.

this happened to me with my 86 vette, the problem is your bleeder screws, they have small check valves in them. Mine had gotten stuck, so it only bleed like just a little when i pumped them up. Replace them, and that will fix the problem.



http://www.speedbleeder.com/



Joe-Flash

ok... the factory bleeders do NOT have check valves in them, only the trick speed bleeders do. The stock bleeders have holes... nothing fancy.

if you think the problem is that bad, remove the bleeders completely... see what happens.

Hi Bogus,
This car is all original so there is no check valves. The brakes were working fine until I replaced the front brakes and clamped the caliper pistons. I have all day tomorrow to fix it. I will check out the master cylinder. I will let you know what I find out. Thanks for your help.


Joe

Did you open the bleeders before pushing the pistons back? This should always be done to prevent such problems that appear to have happened to you. I also flush the system if needed too (and it usually does) before even pushing the pistons back. I'd try Andy's suggestion of bench bleeding the M/C and go from there.

Check valves in factory bleeders, indeed. That's the kind of bullshit advice that predominates over there anymore. And I wouldn't have a set of those speed-bleeders in my car either.

Are you trying a gravity bleed only or do you have a bleeder pump? I use a cheapie one from harbor freight that works great.

Matthew

Hi Guys,

Yeah, I guess I screwed up the master cylinder. I did not open the bleeders before I pushed in the Front pistons. I pulled off the master cylinder and bench bleeded it. Rear pushes fluid, front will not. The old fluid was very nasty. I flushed the system with new fluid. I need a new master cylinder. Although I would like to rebuild it myself but I cant find a master cylinder rebuild kit for it. I need to do my 86 master cylinder too. Do they still make a rebuild kit for these master cylinders?


Joe-Flash man

If you think it's toast, get a brand new one. Rebuilding or rebuilt M/Cs are a crap shoot at best.

It's iffy, but I have had succcess. The M/C on my 92 is a rebuilt from Advance Auto, and has been there since 10/2002.

Not a problem.

There are no rebuild kits for them... at least nothing I am aware of. I suspect that the firms have lost interest in them due to the fact that most people don't rebuild this stuff themselves anymore.

Hey Bogus,How many miles have you put on that rebuilt from advance auto? Did it come with a resevoir? I can get a rebuilt from Advance auto for 65.00, a new bendix for 138.00 or a brand new ac delco with resevior from the GM partladi on ebay for 144.00. I purchased many parts from her and she has all ac delco corvette parts.

Joe

http://cgi.ebay.com/ebaymotors/86-87- ... emZ160269784754QQtcZphoto

I am familier with the partsladi... and have heard some unpleasant stories about parts that were reboxed ACDelco... Check with Central Coaster on that one.

Miles? Gee... Lots... about 100k?

Hi Bogus,

Well, now that you say that, My new ac compressor seems to be dragging. It makes a noise when I turn the ac on or off. Sounds like a squeal. Looks like minimal clearance on the clutch. I just noticed it today. Im gonna be pissed if I have to return that compressor. I will buy the rebuilt for the 87. There are not many parts to replace in a master cylinder. I have dumped so much money into these Corvettes. I cant buy everything new all the time. Thanks for the info.


Joe-Flash man

Quote:

Hi Matatk,

I made my own self bleeder. I used a plastic water bottle with a hole at the top and a vacuum hose thru it. I cant depend on anyone to push the pedal down for me. I do it all myself.



Joe-Flash