Bleeding rear brakes

Nosheruk

Well-known user
I have replaced the rear crossover pipe and rebuilt the rear calipers.
When bleeding brakes the traditional 2 person method, ie press pedal, crack nipple open, tighten nipple when pedal is on floor, then lift off pedal.
Is it normal to sometimes have air drawn i past the lip seals when the brake pedal is on the upstroke?
I used lip seals as there were no o ring kits in stock.
I have gravity bled first and pedal is rock hard and all seems well.
But when i pressure bleed with a helper, i have a constant flow of air bubbles on one rear caliper on one side only. I can actually hear air being drawn in when the wife lifts her foot off the pedal.

If i gravity bleed will this be enough in itself as it doesnt draw in air once everything is nipped up tight?


Regards

Norman
 
Last edited:

kentvette

CCCUK Member
I'm afraid I'd have held out for the O-rings. We used to need to bleed the brakes on our '78 each year, but after fitting new O-Ring callipers the pedal has remained firm for literally years!

The main issue with Corvette (C3) brakes is the introduction of air via the lip seals (and the associated problems as a result). I haven't encountered your exact symptoms, but if the seal is drawing in air during bleeding I suspect it will continue to do so in use, particulalrly if the rotors are out of true. I suspect a careful test drive will reveal that pretty soon.

While I'm aware that some people claim the lip seals are what was there originally and well fitted item should work, my experience shows otherwise. I don't want to "guess" with brakes! I hate to say it, but I'd re-build with O-Rings.

And, there really is no substitute to the two person bleed system, starting at the furthest nipple from the master cylinder and doing all four wheels.
 
Top