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Removing a TR7 stuck brake drum

Posted: 17 Feb 2018 11:42
by UKPhilTR7
I have been having my brake level go down bit by bit over the last six months. Also my car has been sticking at the back end and jolting when moving at low speeds. Almost as if she has kangaroo juice and the back end both sounded and felt as if it was going to fall off.

Today I took the back wheels off to only find that the paint that I had put on the outside of the passenger drum was like fur. There seems to be a leak and the brake fluid is peeling the paint. I think it may be the cylinder.

Currently the drum will not come off and it is stuck. Does anyone have any tricks to remove the drum when it is stuck?

Re: Removing a TR7 stuck brake drum

Posted: 17 Feb 2018 12:40
by rosey
There is an access hole in the backplate to release the shoe adjuster, once you release this you should be able to get the drum off. Don’t try to pry the drum off, turn it, wiggle it and maybe hit it with a rubber mallet if necessary.
May the force be with you!

Re: Removing a TR7 stuck brake drum

Posted: 17 Feb 2018 14:36
by Beans
In my experience disconnecting the hand brake cable will give enough slack in the mechanism that the drums will come of without to much problems.
Sometimes the drum is rusted solid to the flange of the halfshaft, in that case I use a copper hammer to give a few firm wacks on the drum to persuade it :mrgreen:

Re: Removing a TR7 stuck brake drum

Posted: 17 Feb 2018 15:41
by FI Spyder
The drum can wear (especially if at some time the brake shoes where worn down to the metal) such that there is a lip on them. You have to move the brake shoes in far enough (with adjusters making sure the e brake isn't holding them out as suggested) to clear that lip. If they are rusted on you might need more persuasion than a rubber mallet, a bigger drift (punch) and hammer on the edge with some sharp raps might be needed being careful to tap out not up (deforming the drum).

Re: Removing a TR7 stuck brake drum

Posted: 17 Feb 2018 20:26
by Peter Nuss
I would think you need to determine what is stuck on the drum that's keeping it in place. Is it stuck to the axle? Or, is it stuck to the shoes? If it's stuck the axle, a little heat on the axle flange area of the drum and a couple of good smacks with your favorite hammer is in order. If it's stuck to the shoes, or a ridge on the drum you can cut the pins on the backing plate that hold the shoes on and pull the drum off that way.

A little heat does not mean cherry red, a little heat is just enough for thermal expansion. Good luck with your project. Oh, Your favorite hammer also means, not the one you use to drive railroad spikes.

Re: Removing a TR7 stuck brake drum

Posted: 18 Feb 2018 11:06
by UKPhilTR7
I went to the garage again today to try and move the drum, with no luck.it is moving a little but not off. She seems to be stuck to the drums not the studs or the axle. Taps with the hammer did not work. I think that I may have to drill the pins out from the back, that are holding in the pads.

If there is some brake fluid on the drum, does that mean that it will need to be replaced or will a good clean with degrease work?

Re: Removing a TR7 stuck brake drum

Posted: 18 Feb 2018 11:54
by saabfast
The drum and backplate can be cleaned with Brake Cleaner. The shoes should be replaced. (There used to be a thing about boiling them in water many years ago but I would not trust that these days, particularly as the linings are bonded on rather than riveted). The wheel cylinder will either need new seals or replacement. Fun part is getting the spring circlip things that hold the cylinder to the backplate out and in! Use a little graphite to lube the moving handbrake parts. Best to check/do the cylinders both sides as the other will probably not be far behind even if OK now and the shoes come in full axle sets anyway, and you will need to bleed the system when done.

Re: Removing a TR7 stuck brake drum

Posted: 18 Feb 2018 12:44
by Cobber
You'll need to measure the inside diameter of the brake drum to determine if it's still within specs

Re: Removing a TR7 stuck brake drum

Posted: 18 Feb 2018 15:38
by Beans
saabfast wrote: ... Fun part is getting the spring circlip things that hold the cylinder to the backplate out and in! Use a little graphite to lube the moving handbrake parts ...

There is a very simple and cheap little tool for this (Google "rear brake cylinder circlip tool") ...

Image

Re: Removing a TR7 stuck brake drum

Posted: 18 Feb 2018 20:35
by UKPhilTR7
Good one so brake pads replaced and the drums cleaned. I like the look of the rear brake cylinder circlip tool, looks nice and easy to use. Just what you need when in that position.

rosey wrote:There is an access hole in the backplate to release the shoe adjuster,!

I have not seen this on the back. The only holes that I have are for the retaining pins. These are two holes on the drums where you can see the pads, but nothing on the backplate.

Re: Removing a TR7 stuck brake drum

Posted: 18 Feb 2018 21:56
by busheytrader
Hi Phil, I'm not sure by the posts if this has been sorted or not.

My rear brake shoe lining came away from the shoe and jammed itself against the drum making similar noises. The backplate has a hole showing the handbrake self adjusting ratchet inside. This can be released with a screwdriver to retreat the shoes away from the drum. Hope this helps.

Adam

Apologies - the access hole for the self adjusting ratchet may well be in the drum :oops:

Re: Removing a TR7 stuck brake drum

Posted: 19 Feb 2018 20:39
by UKPhilTR7
The good news is that last night I went down to the garage after work to try again to get the drum off and I managed to easy it off. Well ease is not quite the word, but it came off. The inside of the drum looks a mess. Old paint (from the outside) and break fluid all around. For sure it will need new cylinders and pads. I just hope that I will be able to keep the other things like springs,clips and such like. Thanks for the advice and I am looking at getting one of the tools mentioned.

Re: Removing a TR7 stuck brake drum

Posted: 19 Feb 2018 21:16
by Beans
The last time I had to change the rear brake cylinders (May last year), the circlips were included with the new cylinders ...

Re: Removing a TR7 stuck brake drum

Posted: 19 Feb 2018 21:29
by saabfast
Beans, the tool looks useful. When I googled it they ranged from about £10 for a Mini one to over £30 for a 'historic MGB' one. They all look pretty similar. Is there a particular size for a TR7 or are they all the same?

Re: Removing a TR7 stuck brake drum

Posted: 19 Feb 2018 21:44
by Beans
The thread for the bolt should be M10-fine