Caliper Requires Frequent Bleeding

[Bill S.]

I am finding my left front caliper needs to be bled after driving for several hundred miles.There is no fluid leak at the caliper; it just needs to be bled in order to regain pedal height.
The pedal height actually diminishes to the low point where the pedal pressure is excessive
in order to stop the car and actually feels like only the rear brakes are stopping the car.
Then bleeding the same front left caliper gives me a strong solid brake system.
Should I put on a replacement caliper OR check the rotor run-out first.
I recall reading that excessive run-out can allow these lip seal calipers to falter?
Thanks Much

[Patrick H.]

Re: Caliper Requires Frequent Bleeding

I'd put runout first on the list.

Has the rotor been replaced?
Are the left front wheel bearings in good condition?

[Don H.]

Re: Caliper Requires Frequent Bleeding

I agree with Patrick, the rotor is probably "pumping" air into the caliper due to excessive run-out. I had the exact same problem years ago with a '65. Good luck.

[Jim D.]

Re: Caliper Requires Frequent Bleeding

X3 what Patrick said.

[Mark L.]

Re: Caliper Requires Frequent Bleeding

Bill, I'd check the run out with a dial indicator. The spec's are in the service manual. You can shim the rotor to remove most of the run out. Also switching to o-ring seals might be a help.

[Patrick H.]

Re: Caliper Requires Frequent Bleeding

Bill, I'd check the run out with a dial indicator. The spec's are in the service manual. You can shim the rotor to remove most of the run out. Also switching to o-ring seals might be a help.

He still hasn't answered the first questions.

If the rotor has been replaced (or even if not), you can have it turned ON THE HUB and it will fix any runout issues. It's much easier than shimming.

Worn or loose bearings can also cause runout issues, and are easy to fix.

Just be happy it's not a rear caliper pumping air.