kwhiteside

A month ago I rebuilty my rear calipers on my 2001 Z06 and at the time I powerbled just the two rears of all air bubbles. There wan't a whole lot of air.

Today I'm doing a bleed to get ready for the season.

Started right rear, solid blue

Left front, (Wilwoods) both outside and inside solid blue.

Moved to Left Rear, and I can't get rid of the air bubbles. I've been through 5 resevoirs of fluid and still get air. I've never let the resevoir get to the very bottom either. I really don't think all that air is coming from the caliper at this point, but I could be wrong.

Anybody have experience with this much air bubbles?? I'm getting a bit concerned. I really really would like my brakes to be there for me.

JohnD60

Although I have not had your exact scenario I did spend a lot of time trying to get rid of air bubbles that were ultimately caused by a bad bleeder screw.

The screw threads must have been damaged. It felt a little too lose even when turned just enough to start the flow. Replacing it solved the problem.

Probably not your situation since the calipers are new but thought i would share just in case.

Joy of 6

Or if the bleeder hose isn't tight around the bleeder

BEZ06

I was helping a fellow forum member flush/bleed his brakes on his almost new C6 Z06 a few months ago. We had the same problem with a bunch of air bubbles from all the bleed screws - and they were all new OE brakes that had never been bled before.

When we finally figured out the bubbles could not be coming out of the brake system, I initially thought maybe the tube I put on the bleed valve had a hole in it, but after cutting some off the end of the tube it was apparent that wasn't the cause.

We finally decided it must just be some air getting pulled in around the threads of the bleed valve.

We finished up and the car had a good firm pedal. I told him to be careful driving around until he was sure that there wasn't any problem. He drove it for a week or two and took it to the HPDE at Daytona a couple weeks later and had no problems at all.

So....perhaps it's as JohnD60 says, except that it may happen even with good bleed valves. If you get a good solid pedal after bleeding you should have no problems.

Bob

MySR71

If you suspect air being pulled in from around the bleed screw, you can try putting some grease around the screw's perimeter to form a seal. You can then wipe away the grease when you are done.

kwhiteside

Had to go work half a day and was thinking about it on the way home before I saw your comments. Since I'm not a great mechanic and have a history of jacking things up, I'm wondering if those new piston seals I put in might be leaking air.

I'll check the hose tomorrow and cut some off, then make sure its tight. I don't think the rebuild kit came with new bleeder screws, I suppose could be it too.

sperkins

The dust boots have nothing to do with your problem. What kind of bleeder are you using?

kwhiteside

Motive speed bleeder. How about that oring that sits in the groove and the piston slide though it? Could I have messed that up? I dont see any leaking.

sperkins

If it were damaged, fluid would be leaking from the caliper. You can try to swap a bleeder from another caliper to eliminate or confirm that possibility.

kwhiteside

I just snipped the end (which was flared) off and tried again. Solid blue now.

Thanks guys.

It's nice when its the simple fix.