BRAKES!! Really?? Need some help... - Page 2 - Corvette Forum : DigitalCorvettes.com Corvette Forums

drbluevert · 09-28-2012, 07:48 PM

Quote:

Originally Posted by GS81vett

Well I did not realize the left rear block was also where the split took place for both rear wheels so when I pulled the vacuum on the right side the left was apart so that would explain were the leak in this case was. I have ordered new steel lines for both rear sides so I can get a good solid connection and will replace the brass washers on the steel braided lines and test again. Question for anyone reading this long thread has anyone seen a prop valve go bad and allow air in and not push fluid out?

Never. If the valve can suck air in, it would also leak.

How to check your master cylinder. Remove your MC cover, pump out your brake fluid. Disconnect all the brake lines and install a really secure plug like a matching thread bleeder valve on the MC. Re-fill the MC to the proper level and re-secure the MC cap and bale wire. Aply presure to the brake peddel, if it's very firm and stays - the mc is good.

I may like to add that many people that don't have enough experiance with bleeding brakes wind up having more problems afterwords. I prefer using a Phoenix pump and at each caliper pumping fresh bf back up the line to the mc. This eliminates the peddle play with a second person and assures new fresh fluid is throughout the entire system and the prop. valve is good.

Try sealing off the vacuum line from the manifold and tell me how the peddle reacts.

GS81vett · 10-03-2012, 09:43 AM

Thanks I already tested the MC and it is good. I orderd new steel lines for the rear and will make sure they get installed correctly as I think they may be pulling air in and will update you guys then.

GS81vett · 10-04-2012, 03:16 PM

Well I put on new steel break lines on both rear wheels and tightened up everything and bled the system with both vacuum and the old fashion way and I got OK peddle and it can be driven now but it is still not as stiff as I would like and I could use any suggestions. I have a new Wilwood master cylinder and rebuilt front calipers ( I did them and had no issue) and now I have replaced the rear calipers with reman ones and all rubber lines have been replaced with steel and all steel lines have been replaced. The only part still not messed with is the proportioning valve but that should not or can not really fail can it? Still looking for anything I am missing. Thanks

sfallison · 10-05-2012, 06:52 AM

If your still a little mushy on the brakes, try isolating the front brakes from the rear. If the back brakes give you great peddle pressure, then I'd suspect the front brakes are the culprits. I had the same problem, after rebuilding all 4 myself. They lasted for about a year, and then I said "screw it" and replaced them. There was some pitting inside the cylinders, and gave them some slop.

GS81vett · 10-05-2012, 12:46 PM

Quote:

Originally Posted by sfallison

If your still a little mushy on the brakes, try isolating the front brakes from the rear. If the back brakes give you great peddle pressure, then I'd suspect the front brakes are the culprits. I had the same problem, after rebuilding all 4 myself. They lasted for about a year, and then I said "screw it" and replaced them. There was some pitting inside the cylinders, and gave them some slop.

Good thought thanks. What did you replace them with?

Sly Vette · 10-05-2012, 10:12 PM

I had a similar problem with my completely stock system after the restoration 5 years ago. They weren't really bad,the second depression of the pedal would be a bit firmer than the first,just enough to know they weren't 100%.
The next Spring,knowing there was just a bit of air left in the system,I tapped each caliper with a hammer and cracked each bleeder. Problem solved. I couldn't ask for a firmer pedal now.

GS81vett · 10-06-2012, 09:18 AM

Thanks

7t9l82 · 10-07-2012, 03:33 PM

I've seen a hose go bad and do that.when you get it together, jack up the car front and rear open the front and inner rear bleeders let them run onto some old towels and as the fluid runs out of a caliper clear shut that bleeder then last do the outer rear bleeders . make sure to keep the m/c topped off, it may take a while.

sfallison · 10-09-2012, 06:29 AM

Quote:

Originally Posted by sfallison

If your still a little mushy on the brakes, try isolating the front brakes from the rear. If the back brakes give you great peddle pressure, then I'd suspect the front brakes are the culprits. I had the same problem, after rebuilding all 4 myself. They lasted for about a year, and then I said "screw it" and replaced them. There was some pitting inside the cylinders, and gave them some slop.

I got rebuilt brakes from Autozone. About $54.00 each.
Same manufacturer as the originals.