Mot advisories help - rear brake fluctuating?

ses6jwg

My girlfriends 2009 c1 just passed it's MOT at kwik fit (£27 bargain).

However there were 2 advisories I've not seen before

1) rear brake fluid pipe corroded
2) rear brake fluctuating, but not excessively


1 is pretty easy to understand... what would cause 2?

It has drum brakes on rear and covered around 55k

I changes front discs and pads recently would this have anything to do with it? I don't think the car has had a brake fluid change since new could this also be a factor?


Help appreciated

Joe_Horner

Most likely a slightly warped drum but could also be dust, rust or grneral grime in there. Pop the drums off, clean up inside, and if there's no sign of fluid leaking then don't worry about it.

AdrianC

The car is now seven years old - brake fluid is hygroscopic and absorbs moisture from the atmosphere. As it ages and gets "wet", the boiling point lowers dramatically - which can lead to the fluid boiling, and the brakes "failing". It also causes corrosion from the inside-out of brake pipes and cylinders. Failure to change the fluid is the major cause of needing to replace cylinders and calipers. If you're replacing that rotten pipe, you'll need to replace the fluid and bleed through anyway - do all four corners.

But that's not the reason for fluctuations on the drum rears - it's almost certainly just a build-up of grot on the inside of the drum. As Joe suggests, drums off, and a good clean. At 55k, it's unlikely you've had a drum go oval, but new drums won't be expensive.

facade

More importantly, clean the rust off that rear pipe, and paint it with metal paint, or cover it with a thick layer of grease.

Advisory for corrosion means rusty, but the rust scrapes off to bare metal without leaving the pipe pitted.
Treat it now and you will save it, leave it and you will need a replacement next year.

Joe_Horner

AdrianC wrote: »

At 55k, it's unlikely you've had a drum go oval, but new drums won't be expensive.

I'd have said the same until we had one on a Mitsubishi Colt at around 25k (badly enough to feel through the pedal!). then again, we also had a front suspension bush de-bond around the same time - they don't make 'em like they used to

Gloomendoom

I've had a brand new drum that was oval.

AdrianC

Joe_Horner wrote: »

I'd have said the same until we had one on a Mitsubishi Colt at around 25k (badly enough to feel through the pedal!). then again, we also had a front suspension bush de-bond around the same time - they don't make 'em like they used to

That's the kind of faulty-new-part failure that'll often be picked up in warranty, of course.

Gloomendoom wrote: »

I've had a brand new drum that was oval.

I can easily believe that - there are some shocking-quality new parts about.

arcon5

Probably just needs cleaning up, auto adjuster greasing and brake cleaner over drum contact area.
Dust gets everywhere

Won't be brake fluid.

If drum was warped you'd hear it usually, albeit not always

ses6jwg

Cheers folks, so to clean just get the covers off and get in there with a wire brush (carefully) and some brake cleaner?


Will get a wire brush and some hammerite on the pipe too.


I think I will get fluid changed afterwards, quoted £35 at local national tyres who are always very helpful. Don't have the tools myself

AdrianC

ses6jwg wrote: »

I think I will get fluid changed afterwards, quoted £35 at local national tyres who are always very helpful. Don't have the tools myself

The only tool you need is a spanner for the bleed nipples.