Seized Brake Drums

[Dave70968]

Alright, I'll throw this one out to the gearhead brain trust.

1961 MGA 1600 Mk. II. Been in storage since 1989, for reasons not relevant. It has moved in some form or fashion since then, but I think it's been in its current spot since at least 1999, maybe earlier.

We're trying to move it, and the brakes are stuck (disc front, drum rear). We got one front rolling easily, the second took liberal application of various penetrants (ATF + acetone, and PB Blaster a couple of years later). Since getting them freed, I've put motor oil on the pads to the point where I can turn the rotors through freely by hand at the studs (very short lever), and there's a film of oil left to prevent further rust.

Left rear (drum) was really stiff, but with enough force, it got to where we could turn it with a crowbar. Doing so, I slacked the adjuster off fully (the adjuster is accessed through a hole in the front of the drum, not from the rear as with most cars, so the drum has to turn until the hole is aligned to adjust it) and it now freewheels.

Right rear is being a cast-iron *****. I've tried a hub puller with a crowbar through it and literally bent a crowbar (twice!) by standing on the end without any response from the drum. Dad's hit it with a sledgehammer many times, to no avail. I tried a gear puller around the back edge of the drum to pull it off; no dice. There's no place to get penetrating oil onto the surface of the shoes, so that's a non-starter. We haven't tried heat (my torch is being stupid), but that's about all we haven't tried yet. As tight as it is (bent a crowbar!), I don't see that being much help, but I'm willing to talk.

Does anybody have any suggestions that I haven't considered before we go to cutting off the drum? I hate to go that route, but I'm running out of ideas.

(We also need to move it, regardless of what happens with the drum, but that may end up happening with some furniture dollies to get it up on a trailer and move it to my barn. I'm open to suggestions on that idea, too.)

 

[MacFromOK]

I presume you checked/released the emergency brake...

Use a spray (like Liquid Wrench), and spray it into the adjustment hole, pointing it all around as much as possible. Then do the same around the edge of the drum (hopefully some will splatter to the inside).

Whacking it really hard with a sledge probably won't help any more than normal licks with the flat side of a ball-peen, and will be more likely to damage the drum.

You can also drill a few small holes around the backing plate (1/16" or 1/8"), and spray penetrating oil through those. They can be welded up later.

Just a few thoughts.

 

[xseler]

I seem to remember from a foggy, spider-webbed corner of my brain that those may have a 'retainer screw' that holds the drum to the axle shaft. A friend in High School had an early '60's MGA that required weekly mechanical insight. Might check to see if it's hidden under some rust.

Good luck!

 

[NightShade]

So the adjuster on that drum is not in a position to be able to move it to bake the shoes off. Don't forget to loosen the parking brake cable and hose it down with lube. If it is seized as well there is no way the shoe will let it spin even if the parking brake is off. May also want to remove the brake line as that could be a problem, the old rubber hoses can sometimes act as a one way valve and if you put pressure on it will not release. The only thing other thing I can say is get the torch working and hopefully don't kill a seal or hook a chain up to a truck and give it a pull and see if that will break it free. Sadly when they get to the point where they are seized up more than likely something is going to break unless you are going to let it sit for a good long while and soak.

If after all that you can't get it free see what the cost of a new drum is and break it apart with a sledge.

 

[Okie4570]

Once everything is released, heat and a 3lb hammer.

 

[dennishoddy]

Torch. Borrow one or rent one if you must.

 

[Dave70968]

The brake cable is so loose as to be flopping around, and again, the other one turns, so I don't think that's it. @xseler , I know what you're talking about--there are two screws that hold the drum to the hub. For those not familiar with the design, the lug studs come through the back of the hub, through the hub, then the (separate) drum, then out through the wheels and lug nuts. The hub has internal splines connecting it to the axle, but is removeable. We did remove those screws, but they had no effect in either making it turn (for which it shouldn't matter) nor in removing it (which they would prevent were it not otherwise thoroughly stuck).

My next thought is heat. My portable propane torch is being stupid, even with a brand new gas cylinder, but if we can get it home, I'll pick up a rosebud for my oxy-acetylene torch. Frankly, I'm not sure the propane would put enough heat in a large enough area quickly enough to help, but a rosebud on acet ought to do it.

I've already resigned myself to the idea of cutting and replacing, but dad's a cheapass--his next thought is to take the whole axle off (somehow, just removing the backing plate and disconnecting the hydraulic line and e-brake cable isn't getting through to him) and soak it for a month, because that has to work!

A new drum would be $85. He'll screw around with $150 worth of half-ass non-solutions before he buys a new drum. His money, his car, his call.

 

[Dave70968]

Use a spray (like Liquid Wrench), and spray it into the adjustment hole, pointing it all around as much as possible. Then do the same around the edge of the drum (hopefully some will splatter to the inside).

Forgot to mention: due to the shielded design of the drum and backing plate, any penetrant would have to go in, turn 90°, travel about 3/8", make a U-turn, and then move another half-inch just to get to the edge of the brake lining. The adjustment hole is presently located over the "backbone" of a shoe, so it'd take a similar 270° series of turns to get anywhere.

 

[SPDguns]

Can you post a pic? Another option might be to drive the studs out enough to loosen it and get penetrant between the hub and drum. Put a lug nut on the stud and drive them toward the axle just enough until they are loose. Hose it down, let it sit and try again.

 

[Dave70968]

Taken from the Moss Motors catalog:

https://mossmotors.com/mga/brakes/brake-components/brakes-1

The hub isn't pictured; it's considered part of the driveline, nos. 36-38 below (33-35 are for the wire-wheeled version):

https://mossmotors.com/mga/clutch-gearbox-drivetrain/rear-axle-1

(Let me now take a moment to be thankful for such diagrams and catalogs on the internet; I grew up on the paper versions, and still prefer them in the shop, but they'd be nowhere near this useful for a web forum!)