Emergency Brake Doesn't Release

[Martinld123]

Hello, my 1956 Austin Healey 100 BN2 hand brake does not release on the left wheel. The cable is free, but the shoe hangs up for some reason most times now. Not so much in past years.

There is a number on the top shoe, 021579, whatever that means. I bought the car about 12 years ago from someone who had it restored with help of a donor BN1 car, I believe. So it could have some BN1 and BN2 parts. I am starting to think the shoes could be wrong. Any ideas? Thanks, Marty

 

[Bob_Spidell]

The slave cylinder should slide freely on the backplate (that's how the e-brake works). Have someone work the e-brake lever and, if the cyl doesn't move that's your problem; otherwise, the shoes could be stuck.

 

[MikeAH100M]

My guess is that it's not just locking up with the hand brake (since the cable is free) but with also with normal braking. Have you noticed the drum getting hot when you drive? I had this problem of the brake not releasing on my BN2 and it turned out that the piston was sticking (and it took 2 tries to get a functional one from Moss!) You also want to make sure that the adjuster is working and adjusted properly. I also found that the adjuster cams on 2 of my brakes had worked looes from the adjusting pin and made adjusting erratic.

 

[Martinld123]

The slave cylinder should slide freely on the backplate (that's how the e-brake works). Have someone work the e-brake lever and, if the cyl doesn't move that's your problem; otherwise, the shoes could be stuck.

Thank you, I forgot how the back plate should move. If that is it do you think I could but a few drops of oil on the outside only to help it along?? Thanks I will work on it.

 

[Bob_Spidell]

A few drops of penetrating or other light oil on the backplate side of the cylinder, and some 'persuasion,' might do the trick. I put wheel bearing grease--it's tenacious and heat-resistant--on the cyl and backplate where where the cylinder slides and the cyl securing plates during R&R.

 

[NutmegCT]

I *think* the manual says to put some grease on that backplate.

 

[Martinld123]

My guess is that it's not just locking up with the hand brake (since the cable is free) but with also with normal braking. Have you noticed the drum getting hot when you drive? I had this problem of the brake not releasing on my BN2 and it turned out that the piston was sticking (and it took 2 tries to get a functional one from Moss!) You also want to make sure that the adjuster is working and adjusted properly. I also found that the adjuster cams on 2 of my brakes had worked looes from the adjusting pin and made adjusting erratic.

Thanks for reply. Yes, the drum gets hot so I know problem is there. I will try your ideas but also I was just reminded that slave cylinder has to slide freely. will be working on it. Thanks Marty

A few drops of penetrating or other light oil on the backplate side of the cylinder, and some 'persuasion,' might do the trick. I put wheel bearing grease--it's tenacious and heat-resistant--on the cyl and backplate where where the cylinder slides and the cyl securing plates during R&R.

I am going to try your idea but I am worried about getting oil on rubber boot. My only option I think.

 

[Bob_Spidell]

I think, if your cylinder is stuck you should remove it and find out why--rust, dried crud, improper installation, etc.--or it's likely to happen again. Note how the cyl and its fitment plates go together (it may be incorrect). You can use brake cleaner to remove any oil around the cylinder (I buy the stuff by the case). I think it's a good idea to remove the shoes before you apply any fluids around them; the friction material soaks up fluids like a sponge and no amount of cleaning and scrubbing will remove it (ask me how I know). A thin smear of wheel bearing grease on both sides of the backplate where the cylinder and it's fitment plates slide won't cause any issues.

 

[NutmegCT]

A thin smear of wheel bearing grease on both sides of the backplate

Agreed!

 

[Martinld123]

Thanks for reply. Yes, the drum gets hot so I know problem is there. I will try your ideas but also I was just reminded that slave cylinder has to slide freely. will be working on it. Thanks Marty

I am going to try your idea but I am worried about getting oil on rubber boot. My only option I think.

Thanks all that responded. A little lube on both sides did the trick. I am back on the road again. Marty