front drum brake adjusters

"RS" wrote Rich Text in message news:P%Zmf.4009$ snipped-for-privacy@newsfe6-gui.ntli.net...

Your next step is heat, lots of it, with a blowtorch, and a decent pair of mole grips/vice grips/self-locking pliers/whatever your local term is.

Blast, cool, spray wd40, wiggle, blast, cool etc etc.

The adjusters on the rear backplates are replaceable, I believe the fronts are too.

Another thing with the rear adjusters is that they come out of the backplate forwards, ie the same way the drum came off. This may be the same for the fronts. Being a disc-braked Mini owner, I couldn't say for sure.

When you put them back in, make sure there's plenty of copper grease on the backplate threads and the adjuster threads. And it's best, if you haven't already been doing so, to use the proper brake adjusting spanner as it avoids rounding off if they do sieze again.

erik.

I agree with the heat and WD treatment, when the adjuster is rounded off, I have fitted a suitable nut over the damaged adjuster and welded it on, Fitzy

WD40 is not a penetrant. It's a water displacer. If it penetrates at at all it's more by luck than design.

Try a real penetrant such as Kroil or GM General Purpose Penetrant and Heat Valve Lubricant (GM Part # 1052627). More on penetrant later in this post.

Wire brush the area around the brake adjuster. This will cut down on the amount of junk the penetrant has to go through. If it doesn't free up in a couple of days of regular soaking you'll have to go to more extreme methods, heat is a last resort. Also don't try to force the adjuster it will simply round off.

The next step is to remove the brake drum, springs and shoes. Don't let anyone push the brake pedal while the shoes and springs are off. Bad things can happen. Once stripped, use locking pliers on the adjuster barrel on the brake shoe side of the backing plate. This gives much better leverage than the adjuster on the other side. You might want to use a piece of leather between the jaws and the barrel so you don't mark the surface. Even if you do mark the barrel you can clean it up with a fine file later. Spray both sides with penetrant and let it sit for an hour. Try to move the pliers. Repeat as necessary. I have yet to find an adjuster that wouldn't come free after a couple of cycles with this method.

Once free keep spraying penetrant and turning the adjuster until the oil runing out is no longer red with rust. I like to use a spray on white lithium grease for lubrication, again on both sides

In the U.K. you might be able to get the GM Heat Valve Lubricant from a larger Vauxhall dealer parts department, I don't really know but it's worth a try. Otherwise I have heard that Mouse Oil or PlusGas Formula A work well.

Penetrene is supposed to be very similar to Kroil and is available in Australia.

Cheers,

Kelley

managed to take the drums off. the heads of the adjusters are rounded, can i replace the adjusters, or do i need to do the whole backplate?

Not actually a good idea as when they do seize up again and become tight where the weld is, becomes a Heat Affected Zone, and is more likely to break there than release.

Also can this be removed from the backing plate when the nuts are welded in place?

Hi, heat is not good for this application. There is a spring washer behind the adjuster that maintains tension on the adjuster. Too much heat will destroy the spring and leave the adjuster too loose to maintain the adjustment setting.

Keith

have managed to take the drums off. the heads of the adjusters are rounded, can i replace the adjusters, or do i need to do the whole backplate?

Is this washer present on the front only? I don't recall ever having seen one on the rear backplates.

erik.

Although with hindsight it's funny to see pistons flying several feet away from the car.

On the flat faces of the barrel?

I can vouch for the capabilities of 3in1's penetrating spray, although Halford's own brand works just as well and is a pound a can less.

However, I have found that heat and WD40 works better than heat and penetrating spray. It appears that, as heat is applied, WD40 evaporates slower than penetrating spray and if you can align the right amount of WD40 and the right amount of heat in the right place, the boiling of the WD40 does wonders to crack the rust seal.

It also smells nicer.

erik.

Hi, Yes the spring is only on the fronts. The rears are threaded so they stay in their adjusted position. One important thing about the front adjusters. they must be adjusted in the direction that the wheel turns. The left side adjusts clockwise and the right adjusts anticlockwise. I hope this makes sense.

keith

I appreciate what your saying Rob, but after all the time and effort freeing off, I'm sure I would not let them seize up again, adjust every 3 months or so, then grease the outside of the adjuster, should do it, afterall it was neglect that caused them to seize in the first place, Fitzy

As mentioned earlier, with the drums and shoes off just grip the inside barrel of the adjuster with mole grips and rock backwards and forwards whilst increasing the movement each time. I had the same problem recently but loosened the adjuster so much that it became inaffective, i.e. the spring washer became loose. The best solution was to replace the whole backplate, thirteen quid from eBay but a real pig to fit. I couldn't help thinking how poor the whole design was as I rounded bolts and spilled brake fluid trying to fix the problem of a rounded adjuster.

Good luck

There aren't flats on the barrel I'm talking about. The barrel is a big round piece, the piece that adjusts the shoe is an offset pin stuck into the end of the barrel.

I know 3-in-1 penetrant and assume Halfords is similiar. The penetrants I'm talking about are significantly different and better. I haven't used heat to loosen rusted parts in years. Using the holes in the rear of the sills I have even managed remove 30+ year old rear subframe front mounting bolts without breaking them. The last one was on a '61 Mini but I think it had been disassembled in the '70s.

It takes a lot of hindsight to enjoy seeing flying brake pistons. Especially on freshly painted backplates. ;^)

Cheers,

Kelley

Now I understand - having never worked on an all-drum Mini before, I've never looked at front adjusters. The only things they appear to have in common with rear adjusters is that they're screwed in through the backplate and the adjust the shoes...

Hindsight born of desparation, when you sit down after a long day of nothing quite going right, open a beer and someone catches the brake pedal - you either laugh heartily or weep miserably :-/

erik.