Author Topic: Front disc brakes will not release on 72 Europa Twin Cam  (Read 2052 times)

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Offline marks

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Front disc brakes will not release on 72 Europa Twin Cam
« on: Monday,September 14, 2020, 07:33:16 AM »
I am a new member to the forum with my first post; and I am in the process of restoring a 72 Europa Twin Cam basket case.  The calipers have been rebuilt with new brake pads and the brake master cylinder has been rebuilt.  The brake pads do not release and I can not turn the tire with the car up in the air.  The brake pedal seems hard and there is not a lot of travel.   I did try releasing the bleed valve to no avail.  I did take the caliper off the rotor and the discs seem to move in and out okay.  The caliper was a bit tight to reinstall on the rotor.  I am hoping that someone might be able to help me; before I venture to the liquor cabinet.  Thanks!  Mark

Offline RoddyMac

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #1 on: Monday,September 14, 2020, 08:11:09 AM »
- Did you replace the brake hoses?  Old hoses can act as one way valves when they break down internally.

- Is there free play at the pedal?  Try taking the clevis pin out at the pedal and see if that releases the front brakes

Other than that, welcome to the forum!




Offline jbcollier

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #2 on: Monday,September 14, 2020, 08:46:46 AM »
Just double checking, you opened the caliper bleed nipples and they still would not turn?

Offline BDA

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #3 on: Monday,September 14, 2020, 08:48:17 AM »
 :Welcome: marks!!


Offline EuropaTC

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #4 on: Monday,September 14, 2020, 09:28:09 AM »
The calipers have been rebuilt with new brake pads and the brake master cylinder has been rebuilt.  The brake pads do not release and I can not turn the tire with the car up in the air.  The brake pedal seems hard and there is not a lot of travel.   I did try releasing the bleed valve to no avail.  I did take the caliper off the rotor and the discs seem to move in and out okay.  The caliper was a bit tight to reinstall on the rotor. 

Hi Mark, and another  :Welcome:

As John says, did the wheel stay jammed solid when the bleed nipple was opened and fluid dripped out ?  If so then my first thought would be sticking pistons although some brake pad materials are known to stick to iron discs if they are put away wet.

The last sentence is interesting when you say it was tough to get the caliper on. If the pistons are free then they should move to let the caliper go on.  By any chance is the caliper body rubbing on the disc/rotor ?

A servo can apply/hold the brakes as well, especially if there's not enough free movement at the m/cylinder push rod/brake pedal. For reference I think I had around 4-5cm of travel at the brake pedal on the standard Europa TC setup.  More than 5cm feels "wrong", less than 3cm sounds like something is wrong somewhere.

Brian

Offline 4129R

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #5 on: Monday,September 14, 2020, 10:00:52 AM »
I have had the pads stick in the calipers on Europas, (and on a Toyota Corolla GT rally car just before a very fast tarmac stage which I had to do with zero brakes).

Do the pads move freely in the caliper?

Offline Clifton

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #6 on: Monday,September 14, 2020, 11:38:47 AM »
It sounds like your master cylinder is not retracting all the way. There is a compensating port. If it is staying covered, fluid won't return to res and brakes will  not release pressure.

Offline marks

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #7 on: Monday,September 14, 2020, 02:02:32 PM »
Thank you very much for all the responses!  I should have started on this site when I began this endeavor.  I did replace the brake lines with a new braided style.  I did try to bleed at the bleed nipples and nothing happed.  The caliper body does not seem to be rubbing.  I also appreciate the spec on the pedal travel.  I will try taking the clevis out.  I went on the wagon in 1984 and this has almost pulled me off it.  Every one stay safe!  Mark 

Offline jbcollier

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #8 on: Monday,September 14, 2020, 02:13:45 PM »
Sorry for being repetitive:

- the wheel won't turn

- open the bleed nipple

- the wheel still doesn't turn

Correct?

Offline marks

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #9 on: Monday,September 14, 2020, 03:33:32 PM »
No problem on the repetitive:
The wheel does not turn
I did open the bleed nipple
The wheel does not turn
This time I completely disconnected the brake line and the wheel would not turn
The pads were new but many years old
Is it possible that they may have swollen over time; or that I may have the wrong ones in?
A possible solution might be to order new pads or grind the existing ones down?
I appreciate all the help; as this car came in boxes and nothing was labeled
I have the manual; but everything is not crystal clear in it.





Offline jbcollier

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #10 on: Monday,September 14, 2020, 06:27:39 PM »
Thanks for the clarification.

You don’t have a hydraulic issue.  You have a mechanical issue.  Remove the pads and see what’s up.

Offline Grumblebuns

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #11 on: Monday,September 14, 2020, 06:45:30 PM »
I'm still not clear if the problem is with one wheel or with all four wheels. If one wheel and fluid came out when you opened the bleeder nipple and the wheel still won't turn, the pads may be preventing the disc from turning. If no fluid came out, then it may be a hydraulic problem. If all four wheels are locked then look at a likely hydraulic problem.

Never mind, read the title, face plant.
« Last Edit: Monday,September 14, 2020, 07:48:35 PM by Grumblebuns »

Offline marks

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #12 on: Tuesday,September 15, 2020, 07:35:57 AM »
I have ordered new pads to see if the fit is better.  I am hoping for the best!  Thanks for the help!

Offline jbcollier

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #13 on: Tuesday,September 15, 2020, 11:59:54 AM »
Please don't order anything just yet.  REMOVE the pads and see how it is after that.  Are the pads tight?  All of them?  Just inside ones?  Just outside ones?  Something else with nothing to do with the pads?

Offline 4129R

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Re: Front disc brakes will not release on 72 Europa Twin Cam
« Reply #14 on: Tuesday,September 15, 2020, 12:02:48 PM »
I had to grind small bits off the metal backing plate to make the pads move in the calipers.