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MG MGB GT V8 Factory Originals Technical - Front brakes rusted and stuck.....

The car has been sat in the garage for about 3-weeks and it won't move. The engine turns over first time - but the front brake pads are rusted to the disks. What is the best and easiest fix?

Andy
A Butterworth

rusted together in 3 weeks in you garage? Not likely. You probalby have other problems, such as collapsed front brake hoses, master cylinder stuck in bore, etc. Lift up the front wheels and try to spin by hand. If they don't, open up bleeder screw to release pressure. If they still don't rotate try to pry the brake pad back away from the rotor. The wheel should spin. I just can't see rust forming in 3 weeks to the extent of freezing the wheels. Good luck.
Joaquin

I have jacked it up and neither front wheels will spin, they are locked tight. I am a bit stuck at the moment as the wheel brace that was supplied with the car won't fit the nuts (don't laugh I just assumed the one supplied would fit and I haven't had a reason to take the wheels off yet). Looking through the wheels there is definately a lot of rust around the contact between the brake pad and the disk, this is why I assumed it was this.
With regards to bleeding the brakes where is the bleeder screw (apologies for not knowing all this but I am still new to classic-car driving and maintenance).

Thanks

Andy
A Butterworth

If *both* front brakes are stuck on then perhaps the brake switch has somehow got screwed in too far which stops the pedal coming back far enough to release pressure. Have you tried opening the bleed nipples yet? It is on top of the caliper, but you do have to remove the wheels first!

Have you tried breaking the stiction by driving it forwards, or reverse, preferably whichever way won't take you through the end of the garage when they suddenly break free.

But like the man says rusted on after three weeks is impossible, mine have stood for a lot longer than that. It is more likely that the rear drums have stuck on (you have released the handbrake I trust ... ;o)), but attempting to drive off should release those too. If driving forward and the car moves a bit and the nose dips down a bit it *is* the fronts that are stuck on. If the car doesn't move at all when you attempt to drive it it is the rears.
Paul Hunt

Thanks for the replys Paul & Joaquin. I have tried 'breaking them free' as you say a couple of times but they are dead-stuck - slightly frighening when in the garage and all the revs and a rocking car etc, a bit like drag racing starts.
I have managed to get a 24mm socket and am borrowing a torque wrench tomorrow so I will be able to at least get the wheels off.

I have jacked up the rear and both wheels move freely (once the handbrake is released....). The nose dips when trying to drive forward so it is definately the fronts. Looking at the disks and pads through the wheels it definately looks like the pads are attached to the disks though - I'll be able to see more when I get a wheel off..........

Andy
A Butterworth

To be sure there's a lot I don't know about your situation, but a 24mm socket is large for a wheel lug nut. I should think it would be 13/16 inch or a loose 21 mm. I had a 3/4-ton pickup truck with aftermarket wheels and lug nuts, and they were only 7/8 inch. Another thing, a torque wrench is not normally used to loosen wheel lug nuts, but use of a breaker bar (or pull bar) and appropriate socket is. At this point, the amount of force required to remove a lug nut is only academic.

Wayne
Wayne Pearson

Sorry my mistake, the socket is 23mm and it is a perfect fit for the original V8 bolts - they are huge compared to my other car (Audi).

I don't know if this sheds any more light on my situation but prior to being left in the garage I had just returned from a weeks Journey to the south coast (from Manchester), about a 600-mile round trip. The car was fine throughout the week, but it was the week when we had the bad weather (for British standards anyway) and there were some cold days and snow.
On returning home I put the car in the garage and then the following day took it out again to clean it. On the garage floor was a small amount of oil from where I think the gearbox was and a small pool of purple coloured liquid. This didn't look significant at the time but now I am not so sure, if anyone has any ideas I would be grateful

Andy
A Butterworth

It's also possible that your brake pads are simply worn down so much that you are seeing the metal backing on the brake pads in direct contact with the rotors. If the pads are this worn it is possible that the pistons in calipers have been pushed out far enough to get stuck. Usually only happens on older cars with too little brake maintenance. Oddly enough this once happend to me in my MG! It's unlikely, but is possible. The purple fluid could be brake fluid, but most likely gear oil from the differential. Where in relation to the car was the fluid? If you release the pressure by opening the bleader screw or removing the rubber brake hose and the wheel still does not spin, it's time to rebuild the brake calipers. If that is the case, I recommend replacing the hoses while your at it.
Joaquin

OK - I just managed to release the brakes......

I jacked up the front, took the wheels off, opened the bleed screw and hit the pads with a hammer and screwdriver (please don't shout at me). I don't have any axel stands so I did one side at a time. The brake pads were rusted to the disks but I assume this was only because the pistons were pushing the pads against them. There didn't seem to be any big pressure since the brake fluid just dripped out. I think the drivers side disk may be warped though as when I span the rotor it span freely and then caught where it took a lot of effort to get it completely around. The passenger side rotor span freely up to the part where the pad had been then it gripped slightly.

Next steps??

Thanks

Andy
A Butterworth

<<Next steps??>>

A mechanic?

No offense intended, but are you sure that you are ready to risk your life on your wrenching abilities? Better safe than sorry. :)
Carl

Yep, thats what I thought but I'll never learn that way ;o)
I have another car so the MG is more of a 'project'.
A Butterworth

Don't do any more work on the car involving jacking-up till you *do* get axle stands. It is extremely unsafe to be working on a car only supported by a jack particularly when you might be pushing and pulling at things with your head under the wheel arch (or any other part of the body).

With careful leverage (there is actually a tool for this that does it without twisting the pistons in their bores) check you can push the pistons back into the calipers. Hammering is usually no good for this, only damaging compoents, steady pressure is what is needed.

Rotate each hub seeing if the distance between the edge of the caliper and the face of the disk changes (use a screwdriver or similar object as an indicator) as it rotates - it shouldn't. Slowly press down on the brake pedal (or have someone else do it) while you watch the pistons come out again - one might come out before the other but there should be no back-pressure on the pedal until all four are in contact with the discs again.

If you had the caliper bleed nipples open long enough for fluid to drip out it might have let air in, so they will need bleeding.

Other than that simply driving it will rub off any surface rusting from discs and pads, but apply the brakes several times at low speed to check the retardation is adequate and balanced, don't go racing along the motorway at 90 and slam on the brakes only to find you get flipped over the central barrier.
Paul Hunt

Thanks Paul. There is a local mechanic who carried out a service last year, he is only about half a mile away. I think I will take it to him next week if I get chance.

I used the hammer to break the rust that had formed between the pad and the disk; more of a shock tactic that seemed to work. Once each disk was free I drove the car down my drive and tried the brakes - they worked OK but I didn't want to take it on the road, just in case.

When I rotated the disks the passenger side disk seemed OK, but the drivers side one would only rotate easily about half way. After that it was a struggle to get it past the disks - hence why I thought it may be warped.

I aggree I will need to bleed the brakes so either I will get the local mechanic to do it or maybe get a mate around next weekend.

Thanks

Andy
A Butterworth

This thread was discussed between 16/02/2004 and 21/02/2004

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