67 right rear caliper replacement

[Lawrence S.]

Guys, I replaced the right rear caliper, hard line and hose. Gravity bleeding the caliper yielded no hard pedal. Went to the drivers side rear caliper went ahead and gravity bled that one too. Still no pedal. I have a stock dual master cylinder so am assuming I don’t need to gravity bleed the front calipers?
Last time I bled C2 brakes I used a pressure bleeder worked great. At the moment I don’t have that handy.
Please let me know if I need to bleed the front calipers.

Lawrence

[Joe L.]

Guys, I replaced the right rear caliper, hard line and hose. Gravity bleeding the caliper yielded no hard pedal. Went to the drivers side rear caliper went ahead and gravity bled that one too. Still no pedal. I have a stock dual master cylinder so am assuming I don’t need to gravity bleed the front calipers?
Last time I bled C2 brakes I used a pressure bleeder worked great. At the moment I don’t have that handy.
Please let me know if I need to bleed the front calipers.

Lawrence

You should not have to bleed the front calipers if the only thing you did was to replace one rear caliper. If you gravity bleed, how long did you allow it to gravity bleed?

[Lawrence S.]

At least 90 minutes. I have clear fluid coming through the line.
I am now starting to think I got a bad caliper from Zip/Lone Star.

[Mark F.]

did you elevate the rear end of the car when you gravity bled ?

[Lawrence S.]

did you elevate the rear end of the car when you gravity bled ?

I did not the first time but did a portion of the time the second go round. Should I elevate it noticeably?

[Mark F.]

I did not the first time but did a portion of the time the second go round. Should I elevate it noticeably?

When I did mine, I had it on jack stands...can't remember exactly how high they were...

The idea is to get any air bubbles in the brake fluid to rise to the top (float ?) and get pushed out the bleeder valve...

[Lawrence S.]

Back at it with rear much higher. I have good flow but no bubbles coming from the inboard bleeder valve. I will bleed this valve for about 45 mins and do the other valve.

[Lawrence S.]

One interesting point I noticed, the inboard bleeder valve produced a quicker drip of fluid than the outboard bleeder valve. Not sure if that is because of purged air or not?

[Mark E.]

Since you say you see no air bubbles...

- look closely for leaks across the entire system, especially on connections you opened and crimps on new lines.

- check and bleed the front brakes

- check for trapped air in the new caliper by tapping on it while a helper depresses the pedal with the bleeder open. Or use a pressure bleeder. Do this for each bleeder.

[Lawrence S.]

Mark,

look closely for leaks across the entire system, especially on connections you opened and crimps on new lines. Yes, have done this looks good.

- check and bleed the front brakes, have not done that yet.

- check for trapped air in the new caliper by tapping on it while a helper depresses the pedal with the bleeder open. Did this. Or use a pressure bleeder. Do this for each bleeder.
I ordered a pressure bleeder will be here Wednesday or Thursday.

So have been bleeding one caliper for three hours now. Should be bled by now I suppose. I think there is an air lock somewhere is my guess.

[Lawrence S.]

I still have no brakes after pressure bleeding. I did replace the right rear caliper hard line with a 3/16" tube instead of a 1/4" tube brake line. I bought the 3/16" at the parts store and bent it to fit. I am curious if this smaller line is not seating properly on the caliper or the rubber hose. I also replaced the rubber hose. I don't see any leaks anywhere. I am stumped at this point.

FYI, have not bled the front brakes but will do so. The reason I did not bleed the front is because I did not touch those and they were fine.

[Patrick H.]

I'll throw this out - why did you replace the right rear caliper to start?

You've replaced 3 pieces (caliper, hard line, soft line). One of those has to be the problem.
My suspicion is the caliper.
If you know how, I'd consider taking it apart. Since one bleeder seems to work better than the other, I wonder if a crossover passage is blocked.
If you'd prefer not to take it apart, you might have to buy another rear caliper, but you can always contact Zip and see what they say.

[Mark E.]

I still have no brakes after pressure bleeding. I did replace the right rear caliper hard line with a 3/16" tube instead of a 1/4" tube brake line. I bought the 3/16" at the parts store and bent it to fit. I am curious if this smaller line is not seating properly on the caliper or the rubber hose. I also replaced the rubber hose. I don't see any leaks anywhere. I am stumped at this point.

FYI, have not bled the front brakes but will do so. The reason I did not bleed the front is because I did not touch those and they were fine.

Did you have pedal using the old caliper? If yes, troubleshoot by putting it back on. If pedal returns, you know the problem is the new caliper.

Also, install a proper sized brake line.

[Lawrence S.]

SUCCESS! I have a great pedal now after bleeding the front brakes. Not sure why the front brakes were part of the issue since I did not work on them and my car is a 67 with a dual MC, but whatever it is working now.

The reason I replaced the right rear caliper was due to it leaking. About five years ago I replaced the seals on this same caliper with good success, but wanted a fully rebuilt caliper this go round.

Thanks for those who gave me ideas an replied to my post.

Lawrence

[Bill B.]

Lawrence, one possible explanation of why you had to bleed the front brakes in order to restore pedal action may be: if during the course of replacing the rear caliper, if the master cylinder depleted its fluid, air could have entered the brake circuit.