3 replies to this topic

[Tankardrj]

Rear drum has leaked fluid all over my wheel and the drum itself, inspection doesn't show an obvious leak point when brake pedal pished, any ideas on a cause? (Consdiering I know nowt about drums)
Cheers!

[RedRuby]

Would suggest it can only be wheel cylinder, strip the drum off and the brake shoes, peel the rubber dust caps back from the wheel cylinder and see if there is fluid underneath them, if so the wheel cylinder internal seals have failed. If they have it is probably safer and cheaper in the long run to put a new wheel cylinder on rather than a repair kit.

[wile e coyote]

In all likelihood the wheel cylinder has blown - not unusual... and not too hard to fix either - about a tenner should have you sorted with a new one....but - if one's gone then fair bet the other wont be far behind (assuming it's rear you're only talking single ones in each drum) so best to get two and replace both - so 20 quid roughly ...(you can get rebuild kits if you know what it has fitted but - if not - new ones best option) read on....

The brake fluid  will have made a right mess inside the drum and contaminated your brake linings - so...again a new set of shoes(which is all 4)  about a tenner....

Clean it all up (a can of oddly... brake cleaner really handy here) fit new cylinders and shoes, bleed, adjust and you're good to go......with luck!

 

You need no special tools here....... you only have to take off the drum - after slackening the adjuster off.(and potentially disconnecting the handbrake)....remember to readjust afterwards

 

But be prepared for a couple of things (watch out gloom & doom merchant here!) - any of the following could present a problem...
- the brake line (kunifer / copper) from the radius arm to the cylinder corrodes like a pig - copper ones fairly immune - and is very reluctant on occasion to come off and if old & neglected will shear in short order..

- The circlip holding the cylinder on can be a real pig.......has prompted a pinned post in this section - although I've never had an issue with them!

- Bleed the entire braking system when done

- The grub screw on the drum sometimes comes straight out - other times wont budge - impact driver is your friend here

- The brake adjusters rust in nicely - go easy with them!

 

None of it is difficult........enjoy

[spiguy]

If its not from the brake pipe union or the bleed valve, both of which you can (and I assume you did already) check 'from the outside', then the leak is coming from the wheel cylinder which is inside the drum. The fluid you see outside is just what has run out. You need to take the drum off to see what is happening. It will just be a leaky wheel cylinder.

 

Looks like you will need to replace the wheel cylinder. They are cheap, and it's not too hard to do, however there is every chance you will struggle to disconnect the brake pipe at the cylinder end, or may round the nut, twist the pipe etc. I've always managed to undo the big end on the radius arm though. So with that in mind it might be wise to have a spare pipe at the ready.

 

Wheel cylinder genuine:

http://www.minispare...|Back to search

 

Non genuine:

http://www.minispare...|Back to search

 

Brake pipe:

http://www.minispare...|Back to search

 

There is an E clip which holds the cylinder onto the backplate, that can be fiddly to fit. I find sometimes it goes on easy, sometimes not! You get one with the cylinder and sometimes the old one is good enough to re-use in case you ping the new one into the neighbours garden trying to fit it.