e-brake stuck on

[richberman]

Two weeks ago I had an issue with the E-brake staying on, which then led to overheated drum. A tap with the trusty hammer released the brake and I backed off the adjuster 4 flats which led to piston pushing out the cylinder enough to loose hydraulic fluid and all 4 brakes. Took it all apart, cleaned, replaced cylinder and noticed upon reassembly that the end of the E-brake lever does not sit very deep into the rectangular slot of the shoe and wondering if this was the case of the sticking brake. It seems like the felt stops are aligned so the brakes sit evenly on the drums and wondering how to correct this.
Any thoughts?
thanks,
rich

 

[57_BN4]

Rich, are your e-brake levers free when the shoes are fully adjusted, i.e. can you take out the clevis pins and rattle them around? If the e-brake is pulling tight before the shoes have found their home position then it will cause problems.

It sounds like something is badly out of line if you can get the wheel cylinder to pop out by backing off the adjuster. There should be about an inch travel in the wheel cylinder before it pops out so maybe you have incorrect shoes or something. Can you post a pic?

Andy.

 

[Keoke]

Make certain that the end of the E-brake lever fits properly into the rectangular slot of the shoe . It may be a dimensionable problem or just varnish on the shoe.--Fwiw--Keoke

 

[richberman]

Rich, are your e-brake levers free when the shoes are fully adjusted, i.e. can you take out the clevis pins and rattle them around? If the e-brake is pulling tight before the shoes have found their home position then it will cause problems.

It sounds like something is badly out of line if you can get the wheel cylinder to pop out by backing off the adjuster. There should be about an inch travel in the wheel cylinder before it pops out so maybe you have incorrect shoes or something. Can you post a pic?

Andy.

Andy,
Here it was before the sticking.

 

[Patrick67BJ8]

Here's a few pics of my set-up. Note the adjuster is backed off all the way. I assume you did the same when you put the brake drum on? Be sure the "L" shaped E-Brake arm is in correctly and it helps to have a little bit of grease(rubber grease), on it to help it slide for when you adjust the brakes. I just readjusted and bled my brake system again on Tuesday in anticipation of my car coming off the jack stands(frame-up restoration). I never had a problem with the E-brake adjusting since I owned the car(since 1972), but once you completely dismantle something it almost never goes back on the way it was without a fight!

Your E-brake handle should only come up about 1/2 or 2/3's the way when pulled "on" once it's properly adjusted. You may have to disconnect the cable at the pivot fitting near the R/H wheel to get it correctly set again. Let me know if you need other pics of this area??

I also had to completely disassemble the adjusters and smooth the bore to make them slide again like they did when they were new and I also coated the pieces with rubber grease to keep them from corroding.

 

[57_BN4]

The end of the e-brake lever isn't L shaped as in Patrick's pic, but that won't cause the piston to pop out. Maybe somebody has modified the lever?

Your wheel cylinder looks like a 3/4" one (guess) which would be correct for disc brakes if that is what you have. It is a repro so I'm wondering if it is different to the original which allows the piston to come out, i.e. shorter bore. Somebody else posted a while back about the same situation so maybe it is poor quality repro stuff causing this. I can't imagine Girling would have allowed a brake system that could completely fail just by backing off the adjuster as that would mean complete system failure whenever the shoes weren't adjusted often enough.

What is the wear pattern on the shoes like, are they touching the drum all the way around or just in the middle? If the shoes weren't ground to the same radius as the drum it would allow more piston movement when unadjusted. It just doesn't make sense that the piston can come right out.

I am fixing up the brakes on a BT7 today which is identical to your setup but the pistons only move in the lower part of the bore about 1/4" max travel and it would not be possible to have it come out even with the adjuster backed right off.

Andy.

 

[richberman]

Andy,
You are correct, they are 3/4" cylinders. I noticed the end of my e-brake lever is not L-shaped and it does not engage the rectangle as deeply as his. Maybe this is why it got stuck on in the first place but does not explain the failed piston. I will need to look more closely at the failed part. i just threw it in a bag in frustration for now. I wonder where I can find an e-brake lever with Patrick's L-shaped arm as it seems better to fully engage the slot. The wear pattern on the shoe seems pretty even from what I can tell, although it seems to drag more now that I re-assembled it than I remember previously. I had to fully un-turn the adjuster (30 flats or so) to even get the drum over the shoes. Maybe I'll pull it apart again....I also can't get the e-brake to engage without pulling it way up. I've fully adjusted the screw at the right rear pivot to the max.
rich

 

[Patrick67BJ8]

The end of the e-brake lever isn't L shaped as in Patrick's pic, but that won't cause the piston to pop out. Maybe somebody has modified the lever?

Your wheel cylinder looks like a 3/4" one (guess) which would be correct for disc brakes if that is what you have. It is a repro so I'm wondering if it is different to the original which allows the piston to come out, i.e. shorter bore. Somebody else posted a while back about the same situation so maybe it is poor quality repro stuff causing this. I can't imagine Girling would have allowed a brake system that could completely fail just by backing off the adjuster as that would mean complete system failure whenever the shoes weren't adjusted often enough.

What is the wear pattern on the shoes like, are they touching the drum all the way around or just in the middle? If the shoes weren't ground to the same radius as the drum it would allow more piston movement when unadjusted. It just doesn't make sense that the piston can come right out.

I am fixing up the brakes on a BT7 today which is identical to your setup but the pistons only move in the lower part of the bore about 1/4" max travel and it would not be possible to have it come out even with the adjuster backed right off.

Andy.

I meant the end of the cable has an "L" shaped lever that connects to the Brake adjuster not the end of the E-Brake Handle.

 

[andrea]

Hi Rich
I have in the past some trouble with the e-brake-
I suppose that troubles is due to the cylinder I have used, that are NO Girling type, fortunately the pistons pop out at the first attempt, so I give the pistons to a skillful machinist- that easy modifying and make it too long -I not remember how, 3 or 5 mm-
I never have heard same problems on BCF- I suppose that people used the correct pistonsand that they have different dimension, but I haven't confirmation at my supposition others than price that doubled.
please can you control what hind of pistons you used?
Cheers

 

[57_BN4]

Here is the previous thread on this topic
https://www.britishcarforum.com/bcf/showthread.php?88295

Seems the issue was thin repro linings and also noted use of repro wheel cylinders. I wonder if that is a bad combination? Re-sleeving original cylinders is about half the cost of repro ones over this side so worth considering if you have originals. Even completely seized ones fix up better than new for about US$28 each.

What diameter are your drums- have they been turned larger than the original 11"? Also, if you remove the shoes and place in the drum, are they a perfect fit into the running surface? If there is more than about 20 thou rock (hold one end of the shoe against the drum and see how much gap appears at the other end) then they need grinding to suit the drum. If they are replacement shoes rather than re-bonded originals then it is unlikely they will match the drum and possible that there is insufficient lining material on them.

Patrick- yes, I meant the part inside the brake drum, Rich's pics don't show the hook on the end where it goes through the square in the shoe as in your pic.

Andy.

 

[richberman]

Here is the previous thread on this topic
https://www.britishcarforum.com/bcf/showthread.php?88295

Seems the issue was thin repro linings and also noted use of repro wheel cylinders. I wonder if that is a bad combination? Re-sleeving original cylinders is about half the cost of repro ones over this side so worth considering if you have originals. Even completely seized ones fix up better than new for about US$28 each.

What diameter are your drums- have they been turned larger than the original 11"? Also, if you remove the shoes and place in the drum, are they a perfect fit into the running surface? If there is more than about 20 thou rock (hold one end of the shoe against the drum and see how much gap appears at the other end) then they need grinding to suit the drum. If they are replacement shoes rather than re-bonded originals then it is unlikely they will match the drum and possible that there is insufficient lining material on them.

Patrick- yes, I meant the part inside the brake drum, Rich's pics don't show the hook on the end where it goes through the square in the shoe as in your pic.

Andy.

Andy,
Cylinder and shoes are both repro. I will double check the arc of the shoes as you suggested. What is the best method for re-arching the new shoes if they need it? I may look for the originals in the boxes of old parts but I'm not sure I still have them. I also need to investigate the reason the e-brake end does not push through the rectangular hole so much. I'm thinking that may be related to the original sticking issue and maybe even the reason I need to pull up the handbrake lever as far as I do. Sounds like a Sunday project....
thanks for all of the help.
Rich

 

[57_BN4]

What is the best method for re-arching the new shoes if they need it?

The linings have to be thick enough to start with, generally re-bonded shoes are fairly thick and the brake repair shop puts them on a special grinder which removes material until they fit neatly into the drum radius. If your repro shoes are too thin to start with then it may not be practical to remove more material.

One thing you could try is to wind up the adjuster till the drum locks onto the shoes then remove the adjuster-to-backing plate nuts and the wheel cylinder clips/pipe then take the whole lot off as one unit. Then you'll be able to see everything as it sits in situ which should give some indication of where there is enough movement to pop the wheel cylinder out. I had to do this operation last month because the BN2 shoes were firmly rusted to the drums after a 15 year layup.



Andy.

 

[richberman]

I checked the repro shoes and they actually fit the drums pretty nicely. I Did notice the e-brake lever was not seated into the rectangular slot in the shoe once I removed the drum. Interestingly enough, the driver's side (left) e-brake lever is not L-shaped and hence can easily pop out of the the shoe while the passenger side lever has an L-shape and can't pop out. I wonder why they are not the same? Now I'm thinking I may have over tightened the inner adjustment posts which hold the shoes centered and maybe that is why the lever popped out. I've now screwed those two pins towards the car center and the lever sits inside the shoe a bit better, but I still think the L-shape would make me feel better.
I do think the shoe material on the repros is a bit thin too. When the e-brake is not connected to the entire mechanism I can tighten the adjusted full bore and still turn the wheel (it drags though). Once I connect the e-brake to the cross rod then the adjuster makes the shoes bind 5 flats off of full. Anyone know where to get thicker linings? or an L-shaped e-brake lever?
I looked for my originals to no avail.
Rich

 

[Patrick67BJ8]

I checked the repro shoes and they actually fit the drums pretty nicely. I Did notice the e-brake lever was not seated into the rectangular slot in the shoe once I removed the drum. Interestingly enough, the driver's side (left) e-brake lever is no l-shaped and hence can easily pop out of the the shoe while the passenger side lever has an L-shape and can't pop out. I wonder why they are not the same? Now I'm thinking I may have over tightened the inner adjustment posts which hold the shoes centered and maybe that is why the lever popped out. I've now screwed those two pins towards the car center and the lever sits inside the shoe a bit better, but I still think the L-shape would make me feel better.
I do think the shoe material on the repros is a bit thin too. When the e-brake is not connected to the entire mechanism I can tighten the adjusted full bore and still turn the wheel (it drags though). Once I connect the e-brake to the cross rod then the adjuster makes the shoes bind 5 flats off of full. Anyone know where to get thicker linings? or an L-shaped e-brake lever?
I looked for my originals to no avail.
Rich

Rich, Can you take some pics of both levers that go to the rectangular holes in the shoes and post them? Also, can you remove both pistons from each of the adjusters easily or do they bind?

 

[57_BN4]

Sounds like the problem is the thin linings, and possibly oversize drums. A brake shop should be able to re-bond your shoes with oversize lining material then grind it to the drum size. Some lining material squeals like heck when cold so ask for non squealing material if you end up going that route.

You should be able to lock the drums firmly and positively within about two turns of the adjuster from fully backed out. Also the e-brake linkages shouldn't change how tight the shoes are, when the e-brake is off the levers should be completely free from the shoes albeit very close to pulling on them. Unwind the rear end clevis on the cable if necessary until the L levers are just free.

If you can't get an L-lever locally I can probably find one here.

Andy.

 

[richberman]

Sounds like the problem is the thin linings, and possibly oversize drums. A brake shop should be able to re-bond your shoes with oversize lining material then grind it to the drum size. Some lining material squeals like heck when cold so ask for non squealing material if you end up going that route.

You should be able to lock the drums firmly and positively within about two turns of the adjuster from fully backed out. Also the e-brake linkages shouldn't change how tight the shoes are, when the e-brake is off the levers should be completely free from the shoes albeit very close to pulling on them. Unwind the rear end clevis on the cable if necessary until the L levers are just free.

If you can't get an L-lever locally I can probably find one here.

Andy.

Andy,
How thick should the linings be. I'm thinking this is why I need to turn the adjusters so far.
rich

 

[healey106]

Rich - I may have some linings in the garage with my other Longbridge items. I will get back to you - jim

 

[richberman]

Jim,
Thanks for looking. Maybe an L-shaped e-brake lever too?
rich

 

[57_BN4]

Andy,
How thick should the linings be. I'm thinking this is why I need to turn the adjusters so far.
rich

I don't know of a specific thickness but 3/16 is about what they are usually. The thickness you require depends on how much oversize your drums are. I have oversize shoes on my Ford and they started at about 3/8 thick before being radius-ground to suit the drums. They are now about 5/16 thick.

Another method I have used several times in the past on other vehicles to correct your situation is to add a thick bead of weld to the shoe ends where they contact the adjuster tappet/cylinder. This works very well if the shoe is a good fit inside the drum already but the adjuster is not in its useful range. I'll leave it to your better judgement to decide whether modifying brake parts in this way is right for you.

Andy.

 

[richberman]

I don't know of a specific thickness but 3/16 is about what they are usually. The thickness you require depends on how much oversize your drums are. I have oversize shoes on my Ford and they started at about 3/8 thick before being radius-ground to suit the drums. They are now about 5/16 thick.

Another method I have used several times in the past on other vehicles to correct your situation is to add a thick bead of weld to the shoe ends where they contact the adjuster tappet/cylinder. This works very well if the shoe is a good fit inside the drum already but the adjuster is not in its useful range. I'll leave it to your better judgement to decide whether modifying brake parts in this way is right for you.

Andy.

Andy,
I think thicker linings would be safer in my hands not knowing how to weld....
thanks,
rich