Brake seized

[Eric in France]

Hi

I use my BMW very little, and recently I've noticed that it didn't seem to coast very well. Then, a few weeks ago, I used it and it was even worse, slowing down if I took my foot off the gas. Eventually I got to a red light, and I saw that there was smoke coming from the right rear brake. When the light turned I drove forward and turned left, applying the brakes briefly. When i pushed the pedal, at first there was no resistance to my foot, and then when I lifted my foot and tried again it was normal. I quickly parked the car and left it a couple hours. When I came back I tried carefully driving home (with my daughter following in her car), and everything was normal. It no longer had the problem of slowing down, and the brakes worked fine.

Since then I haven't used the car. I would like to understand what the explanation is for what happened. I suppose I have air in the hydraulic line or something, but I don't understand how that causes the problem I had.

[Mikealwa]

Just some wild guesses, but I'd take your wheel off and brakes apart and inspect. Maybe your guide pins are rusty causing the brakes to stick? With inactivity maybe some parts need some TLC or at least inspecting. if it's been used in frequently.

- - - Updated - - -

Air in a line would cause a spongy pedal, but it would t fix itself without bleeding the brakes.

[323i E30]

Years ago I had a somewhat similar issue after a hard braking.
The brakes would start slowing the car more and more until it would become impossible to drive normally. Letting the car rest and cool down would normalize it for a couple of miles. Then it would start again.
If I remember correctly the issue for me was in the brake booster.
Not 100% sure though. It’s been a while.

[dworthy]

Also have a look at your rubber lines, for they can be collapsing internally. What happens is it allows fluid to go to the wheel cylinder, but once you take your foot off the brakes, it doesn't allow the fluid to return.

[tomstin]

Most likely, as dworthy suggests, the rubber hose has collapsed internally. The other possibility is the piston inside the caliper has seized. Brake fluid retains moisture (hydroscopic) which is why BMW recommends bleeding every two years.

[jamespaleo]

I"ve also had issues with the rubber hose collapsing internally. You could try that as it much cheaper and easier than most anything else, and any rubber hose on these now 30+ year old cars that you have not replaced yourself should be considered suspect anyway.

[Eric in France]

Thanks to all of you. I will try looking at it when the weather is warmer.

I wanted to get notified when there were replies, but couldn't find how to request that.

[dworthy]

At the top on the right side you have a button called "Tread Tools" Just make sure you are subscribed and your email address in your profile is correct.

[Eric in France]

Thanks, Darin. Actually I did that, and this time it worked -- I got a notification about your reply.

[Eric in France]

Well, the weather finally got pleasant and I tried to take off the drum to see what I could see. But I couldn't get the drum off! I tried banging on it with a "rubber" mallet, but to no avail. When I tried to put the little screw back in which is supposed to hold the drum in place, I couldn't get it to thread itself in. Then I thought I would drive around the block to see whether the brake was still working all right, as it was when I drove home in December, but the brake is completely seized.

Any suggestions for getting the drum off? I have a Haynes manual and it says if the drum doesn't come off, slacken both shoe adjusters. But I don't see any "shoe adjusters", even looking on the back side with a mirror.

I suppose the reason I can't get it off is that the brake is on.

[82eye]

Well, the weather finally got pleasant and I tried to take off the drum to see what I could see. But I couldn't get the drum off! I tried banging on it with a "rubber" mallet, but to no avail. When I tried to put the little screw back in which is supposed to hold the drum in place, I couldn't get it to thread itself in. Then I thought I would drive around the block to see whether the brake was still working all right, as it was when I drove home in December, but the brake is completely seized.

Any suggestions for getting the drum off? I have a Haynes manual and it says if the drum doesn't come off, slacken both shoe adjusters. But I don't see any "shoe adjusters", even looking on the back side with a mirror.

I suppose the reason I can't get it off is that the brake is on.

sounds like your parking brake is seized. you might be able to get it to back off by loosening the star adjuster through one of the lug holes.

[dworthy]

+1

Also as the shoes wear away the drum, you will get a lip. That lip will catch the shoes and be a real PITA to get off without releasing the adjuster back.

[Eric in France]

Thanks for the tips. I managed to get the drum off after releasing the parking brake (a bit stupid that I didn't realize before that I had to do that!). I didn't have to try to turn the star adjuster through a lug hole, fortunately! Once I had the drum off, I did turn the star adjuster (not very easy) and banged the shoes around a bit before putting the drum back on. It seemed to be fine. Later I drove the car to do the biennial safety test (which was overdue because of the brake problem) and the car still seemed to slow down a bit too fast when coasting, and at the test they found that the brake on the other side (the left rear brake) was gripping a little. So the other day I got the drum off of that side (which was rather difficult), and backed off the star adjuster on that side as well. Now that wheel rotates much more easily, although it still seems to have a bit of friction once per revolution. However, i noticed that when my wife would push the brake pedal, the piston on the left side of the cylinder moves out, but the one on the right side doesn't move. So I suppose the rear shoe does not touch the drum when the brake pedal is pressed. Before putting the drum back on, I tried to push rightward on the left shoe (with the brake pedal depressed), to try to get both pistons to move, but I didn't succeed. (This did work on the right rear brake.)

I wonder how the brakes got to be too tight. I wonder whether it has something to do with the fact that I used the car very little over the last year or two. As though things got a bit stuck.

After fixing the brakes we used the car last Sunday and the fuel consumption gauge showed around 6 litres per 100 km, which is normal, whereas I calculated that on the last tank of gas I was consuming twice that, because of the brakes!

I did have a problem with the temperature. I had to stop twice and add coolant. I think that was because I hadn't properly filled the cooling system after a hose came off last year. There doesn't seem to be a leak.

I've noticed that the exhaust is rather visible. I suppose that means I need a ring job?

When I tried to post this, I got a message, "Your submission could not be processed because you have logged in since the previous page was loaded. Please reload the window." But that didn't work! And I wonder whether there's a mistake in the English of that message -- I don't understand it.

[dworthy]

I cannot help you with the Mod's stuff from the forum, sorry.

What I can help with is the other stuff, so brake fluid is hydroscopic, this means it will absorb water and capture it in the fluid. The fluid requires regular replacement because of this even if the car doesn't get driven much, as the system isn't sealed. So every 2-3 years you need to replace the fluid, as this will keep problems to a minimum. I would replace that wheel cylinder, as you should be able to push in on one side, and the other will come out.

Dragging brakes will defiantly increase your fuel consumption, on drum brake systems, use a heat gun to see which drum is hotter. On regular disk brake types, one wheel will be much dirtier than all the others.

[Eric in France]

Thanks. Here's an update:

I took the car for the safety test again in July, and the guy told me that there was still an imbalance. He said I should take it to a certain garage near where we live that deals with old and classic cars. I asked there and was told that because of the August vacation (we're in France!) they couldn't take me till October. So I made an appointment and brought the car in October and explained the problem with the rear brakes. After a week I went to see, and the boss was on vacation again, but his wife called him and he said they would need to replace the wheel cylinders and the brake shoes (of the rear brakes), but also the calipers, pads, and disks (of the front brakes), the master cylinder, and the hoses! I was given a quote for 1178 euros. When the boss came back I went and talked with him. He said they wouldn't agree to do anything less. So I said I would get another opinion and maybe come back. I took it to the garage across the street from our apartment, and the guy there said it needed a brake kit and wheel cylinders. I let him do it, and it came to 583 euros. He also replaced one hose which he said was rusty, and replaced the brake fluid.

I don't really understand why it needed the brake kit. I replaced the shoes four years ago (not very many miles ago!) for 20 or 30 euros, avoiding buying a kit for 150 euros! Now the kit was 227 euros (with tax).

A few days later I took it for the safety test and it passed. But I still had the problem I mentioned of overheating. Later I let the motor run and added more coolant, but I ran out. Now I have another 5-litre jug. I think I have put in a good 10 litres already, and the capacity is just 10.5 litres. So I'm a bit mystified. But I see no leak.

[Mikealwa]

Did you bleed the coolant system appropriately? If there's air in there you might overheat. Google the procedure to bleed the coolant system. If I remember correctly some people raise the front end turn the heat on full blast and wait till the engine is warm, then you open the bolt above the thermostat untill only fluid comes out with no bubbles.

The first shop might have given a fair price. They must have seen rust and age etc on the brake components where they were in willing to take risks in only replacing some of the components only for the some other parts to fail. So a responsible shop wouldnt want to risk only fixing the system enough to make it work knowing some other part was on its last legs and you'd be back in in a few months.

[aaverhulst]

Thanks. Here's an update:

A few days later I took it for the safety test and it passed. But I still had the problem I mentioned of overheating. Later I let the motor run and added more coolant, but I ran out. Now I have another 5-litre jug. I think I have put in a good 10 litres already, and the capacity is just 10.5 litres. So I'm a bit mystified. But I see no leak.

Previously you mentioned you could see the exhaust. Exhaust comes in 4 types, clear - you can't see - the way it should be. Black which means car is running rich, Blue or grey - burning oil, and white - internal coolant leak. If you are adding coolant and see no leak you may have the white smoke - an internal leak, like a head gasket.

[82eye]

agree with aaverhulst

you have a bad head gasket