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Posted by: EJP914 Jun 12 2021, 09:44 PM

I am bleeding the brakes on my 73 1.7 with a Motive power bleeder after replacing the calipers, rotors, hard and soft lines at each wheel. The rears and right front bled out great. No air bubbles and continuous flow of fluid. Problem is on the left front.

When I pressurize the brake system via the bleeder tank and open the bleed screw I do get a small amount of bubbles in the catch jar. While the system is under pressure (about 10 lbs) and bleeder screw closed, the brake pedal is at the top and very firm the way it should be. Once I release the pressure in the tank, the brake rotor spins free. That little bit of contact you typically get with the pads is gone. Brake pedal has also lost its firm feeling. The right front wheel has that little bit of drag from the pads.

I have checked all over and nothing seems to be leaking. If there was leak somewhere, I don't think the bleeder tank would hold at 10 lbs.

Any ideas on why this is happening? Bad caliper?

Would very much appreciate the help.

EJP914

Posted by: willieg Jun 12 2021, 10:55 PM

I bought a rebuilt caliper once from one of the cheapo places and had the same issues. I split the caliper apart and found one of the passages through the caliper was blocked with debris. Cleaned out the blockage, reassembled the caliper and it worked

Posted by: EJP914 Jun 13 2021, 08:59 AM

Thanks Willieq.
Any other thoughts out there before I remove the caliper???
Thanks

Posted by: mepstein Jun 13 2021, 10:33 AM

Make sure the soft lines are new or newer.

Posted by: cary Jun 13 2021, 11:25 AM

New brakes I leave over night at 20#'s to test for leaks.

Posted by: EJP914 Jun 14 2021, 06:21 AM

Soft lines at the wheels are new.
Have had system at 15 lbs for multiple hours and no leaks found. Will do again as suggested

Posted by: bdstone914 Jun 14 2021, 06:38 AM

@http://www.914world.com/bbs2/index.php?showuser=821
Sure sounds like an internal caliper blockage. You may get lucky by removing the hard line and retracting the pistons and flush out the blockage. If not it sounds like you need to split the caliper.

Posted by: infraredcalvin Jun 14 2021, 07:44 AM

Agreed, just had a similar issue, I had a hanging caliper on my car, It would not bleed. I removed both bleed nipples, found they were both clogged. Cleared them, rebled system, now everything works as it should. Turns out caliper was only partially full of fluid.

Posted by: EJP914 Jun 14 2021, 09:03 AM

Many thanks guys. Caliper is under warranty. Supplier is ordering me a replacement. Hope that cures the problem. Driving me nuts

Posted by: bdstone914 Jun 14 2021, 09:11 AM

You may want check the replacement before installing. Place a wood block bewteen tbe caliper halves about the thickness of the rotor. The pistons should move with about 50 lbs of air pressure.