TR2/3/3A Rear brake drum won't go on?

[karls59tr]

The drum seemed to be seized as I could not turn it. The car had been sitting for some time. I managed to get it off but it took a lot of work. I cleaned up the drum and brake shoes. When I tried to refit the drum there is no way it would go on.The park brake cable is not causing the issue. I lubricated the adjuster and tried backing it off so I could get some clearance. The adjuster dosn't appear to be moving those little "pistons?" inward?( What do you call those things anyway) Can the adjuster mechanism get stripped so that when you do the adjustment it dosn't move the pistons or can the pistons themselves seize up? What am I missing here?:confusion: The drum on the drivers side came off and went on with no problem. Almost forgot...I filed down the shoe material on the leading and trailing shoe edges but still no joy?

 

[TR3driver]

All of those things are possible, though I'd say having the steel wedges seize into the aluminum housing is most common. Suggest you remove the adjuster for cleaning and inspection.

It's also sometimes necessary to tap the slave cylinder around a little, and/or get the shoes positioned just right for the drum to go on. But you definitely want the adjuster to work, even if it isn't keeping you from installing the drum.

Since you didn't mention it, it is also possible for the slave piston to become seized into the slave cylinder. For a car that has been sitting for a long time, I would always rebuild the slaves if only to check the condition of the bore. Conventional brake fluid, plus steel and aluminum in contact, almost guarantees galvanic corrosion.

 

[bobhustead]

Those little adjuster "pistons" are cylinders with an angle cut across them. The adjuster screw is tapered and when tightened pushes the pistons out. When the screw is all the way out, the pistons should touch each other, which you can see thru the hole in body of the adjuster. If they don't, they are seized. It is not the adjuster that draws the pistons together, but the springs on the shoes that push the pistons together.
Bob

 

[poolboy]

Would opening the bleeder help ?

 

[karls59tr]

Would opening the bleeder help ?

I was wondering the same thing.

 

[CJD]

I was wondering the same thing.

Not if the other side came off without a hitch. Murphy would never let you off that easily!

 

[bobhustead]

Opening the bleeder is not likely to help. Nor would it hurt. You should be able to look at the wheel cylinder and see if it is extended. Extension by hydraulic pressure would imply that the master cylinder piston is stuck hard down, which in turn would have all the brakes locked.
Bob

 

[NutmegCT]

A couple thoughts from someone who's been there - ME!

Is the "tight" drum the "correct" drum? I found a previous owner had replaced the drum, and it didn't match the curve of the shoes.

Do the adjusters actually move the shoes? Both in and out?

Are the shoes the proper size, curve, width, etc.?

Tom

 

[karls59tr]

Not if the other side came off without a hitch. Murphy would never let you off that easily!

CJD This is off topic and I think I asked you this once before a long time ago but what color is your 3A? In the picture it looks a lot like mine which is a Jaguar color... sort of silver blue metallic.:eagerness:

 

[karls59tr]

A couple thoughts from someone who's been there -

Do the adjusters actually move the shoes? Both in and out.

Tom

I think that's the problem. I'm going to pull out the adjuster like TR3driver suggested and clean and inspect it.:smile-new:

 

[sp53]

Well it sounds like you have the 10 inch drums, and that you are not using new shoes. There is very little wiggle room. Take a very careful look at the shoes and make sure they are centered on the axle. When the adjuster is all the way back, you can take the drum hold it perpendicular to the axle plane and gently with the drum grab both shoes and gently kinda wiggle and whirl around just a fuzz then push in at the same time. It should go. Now see if you can turn the drum. You might have to rock the drum back and forth to get some movement. If you can move it with your hands with the tire off that amount of drag should re-center itself just driving around the block, but if not you might have to true the drum or grind the shoes.

 

[karls59tr]

Problem solved.I had one or both adjuster cylinders in bassackwards. Doh!

 

[NutmegCT]

Problem solved.I had one or both adjuster cylinders in bassackwards. Doh!

Hey - glad you got it figured out!

Fortunately none of the rest of us have ever made any mistakes ...