Technical Rusted rear wheel drum won't move

[AnthonyH]

I could quite happily have done an apprenticeship in auto repairs many years ago, but alas I did other things. A few years back I volunteered at a motor museum, they restored old trucks and vans from any time but seemed to like the 1950s models. I did computer work, rather than the restoration though!

I got the new brake cylinder this morning, the bleed nut is 1mm bigger than the old one and my 8mm spanner has gone walk about, so I put the cylinder on knowing I couldn't bleed it today. After the cylinder went on I could see a leak from the nut that is going in from the brake line. It appears that it wasn't leaking from the bleed nut at all but from there. I really wish I'd put my glasses on to check where that leak was coming from LOL

I'm now looking for a brake line nut...do they have some kind of rubber seal to prevent the fluid from leaking out? It doesn't look like they would ever be water tight!

 

[The Panda Nut]

No. Either is got some grit on it, and needs cleaning, or the pipe is damaged or the nut needs a little more tightening say 1/8 of a turn or a little less or the brake pipe has holed inside the nut and you will need a new brake pipe. Not tight enough if you are lucky. Brake pipes go throught the brake union nut and have a flared end that then compresses against the cylinder when tightened, Metal to metal. The end of the pipe inside the union nut is the first place brake pies tend to fail. Nuts need to be tight but not too tight as this damages the flare on the pipe, Do up until secureley seated then nip the nut up just a bit more. Small spnner one hand good frim turn from your wrist is just enough. Wipe the join clean with some paper towel and inspect after giving the pedal a good push and it must remain dry.

 

[AnthonyH]

No. Either is got some grit on it, and needs cleaning, or the pipe is damaged or the nut needs a little more tightening say 1/8 of a turn or a little less or the brake pipe has holed inside the nut and you will need a new brake pipe. Not tight enough if you are lucky. Brake pipes go throught the brake union nut and have a flared end that then compresses against the cylinder when tightened, Metal to metal. The end of the pipe inside the union nut is the first place brake pies tend to fail. Nuts need to be tight but not too tight as this damages the flare on the pipe, Do up until secureley seated then nip the nut up just a bit more. Small spnner one hand good frim turn from your wrist is just enough. Wipe the join clean with some paper towel and inspect after giving the pedal a good push and it must remain dry.

Righto, I don't have time to do that today, but I'll have another look tomorrow. The first thing I tried was giving it another tweak by hand to tighten it, and it turned a little, but then it wouldn't go anymore and was still leaking. So I'm not hopeful but we'll see.

 

[The Panda Nut]

If you can undo it get the nut free on the pipe and slide it away from the union you can them inspect the pipe for condition. Many pipes are plastic coated and once the coating goes, inside the nut its hard or impossible to get the nut back as it catches on loosened plastic coating but a little work and some light oil helps.

 

[vexorg]

If the brake line was rusted at the nut, and they often are, the force of undoing the nut can crack the pipe.

 

[AnthonyH]

If you can undo it get the nut free on the pipe and slide it away from the union you can them inspect the pipe for condition. Many pipes are plastic coated and once the coating goes, inside the nut its hard or impossible to get the nut back as it catches on loosened plastic coating but a little work and some light oil helps.

It was quite gritty when I was tightening it back up. I just thought this was part of the tightening because it needs to be a tight thread. But I'm thinking the gritty feel was some plastic and it could be cleaned. I'm a little reticent about getting it off now though, because I think it might be getting into rounded off territory without a flare spanner. I bought one last night to pick up at Halfords this morning, when I got there they said someone had previously stolen it and the stock was showing but it wasn't there. They have a problem with shoplifting!

 

[vexorg]

You need a brake spanner, it's like a ring spanner with a cut out for the pipe. That gives maximum grip. And the nuts do round quite easily.

Gritty thread isn't ideal, but it's the end of the flared pipe that's critical to be clean.

 

[vexorg]

Sorry, we're down for maintenance

This kind of thing, but the for the correct size.

 

[AnthonyH]

Sorry, we're down for maintenance

This kind of thing, but the for the correct size.

It is a similar one that I bought from Halfords except size 9mm x 11mm. The nut itself is 11mm and I'm using an 11mm regular spanner. I couldn't see how that flare spanner would fit over a 11mm nut, but thought I'd buy it and see! I presume another 11mm will be OK? So i'll try to re-order from a different Halfords, which hopefully hasn't been pilfered

 

[vexorg]

It's an 11mm nut and 11mm spanner then it will work. Put the pipe through the slot then slide the spanner on to the nut.

 

[The Panda Nut]

Its a ring spanner with a bit missing from the ring so you can get it past the pipe. Worth every penny. Dont try with a standard spanner these seem always to wreck the nut as Vexorg has said.

 

[The Panda Nut]

Sounds like you tried to pump the pedal before putting the drum back.. NEvER do this as this will be the result. I did it once many many years ago. If you must do this you need an asistant to ensure the shoes cannot move more tham a fraction bu holding something against the backplate amd also only ever press the pedal part way down and both slowly and gently. As soon as movement is seen at the cylinder/ piston stop. Better still, dont do it. Pressin one piston in should move the opposing one out so you can check nothing is sezed with your fingers. You still need to take care not to over do it and send the piston too far,

 

[AnthonyH]

Sounds like you tried to pump the pedal before putting the drum back.. NEvER do this as this will be the result. I did it once many many years ago. If you must do this you need an asistant to ensure the shoes cannot move more tham a fraction bu holding something against the backplate amd also only ever press the pedal part way down and both slowly and gently. As soon as movement is seen at the cylinder/ piston stop. Better still, dont do it. Pressin one piston in should move the opposing one out so you can check nothing is sezed with your fingers. You still need to take care not to over do it and send the piston too far,

The original problem was caused by me pumping the brakes with the hub off, never again!

I'm hopeful I can get the new brake cylinder to work without needing a new brake line.

I managed to get a 11mm flare spanner, the one pictured above from a different Halfords store, this store had theirs locked up for safe keeping!

 

[The Panda Nut]

Same thing applies to discs. If the pads are out you will pop the cylinder / piston. You can insert something to restrict piston movement so you can check for movement of the piston with discs with less risk. You may need to apply heat to the brake pipe to get the union out / undone. Its a bit of a pain. DOnt use large amounts of force or you will wreck things. If you get some movement workthe nut back and forwards. Go slow!

 

[AnthonyH]

Same thing applies to discs. If the pads are out you will pop the cylinder / piston. You can insert something to restrict piston movement so you can check for movement of the piston with discs with less risk. You may need to apply heat to the brake pipe to get the union out / undone. Its a bit of a pain. DOnt use large amounts of force or you will wreck things. If you get some movement workthe nut back and forwards. Go slow!

I attempted to undo the nut, yes, and then it was stuck so tight I thought no no, better stop and have a think.

I'll go back and forth tomorrow as you suggest and cross my fingers!

I could possibly use a lighter with an elongated nose to heat it, if necessary, not sure what else I've got.

 

[bugsymike]

In fairness and no disrespect, I suspect this job has got a little bit larger than you expected and you are slightly outside your comfort zone.
Given that it is brakes and you and your family may have to depend on them, it may be time to ask someone with a bit more hands on experience cast their eye over it.

 

[AnthonyH]

In fairness and no disrespect, I suspect this job has got a little bit larger than you expected and you are slightly outside your comfort zone.
Given that it is brakes and you and your family may have to depend on them, it may be time to ask someone with a bit more hands on experience cast their eye over it.

I'm not driving it anytime soon no, I do have two other cars so there's no rush to get it done, if it ends up at a garage, that's OK.

 

[vexorg]

I'd be very careful if heating the nut, I'd worry about overheating the fluid or damaging anything rubber around the piston.

Tapping the spanner end with a hammer works well too to give an impact effect, rather than straight force.

Sounds like you tried to pump the pedal before putting the drum back.. NEvER do this as this will be the result.

I always put a cable tie around the cylinder to hold the pistons in when workng on the rear brakes. Then cut it off when the shoes are all back in place.

 

[AnthonyH]

I got the pipe off OK, the new spanner was a big help. The cylinder and brake pipe flange have a little scoring/scratch, I don't know if that's the problem, i.e. I overtightened it last time. But i'll clean the thread, retighten and hope for the best...

 

[vexorg]

I'd say that will be fine once tightened