Morris Minor Owners Club

Anyone know why my brake reservoir is low after two weeks use and then the brakes fade (two pumps each time) and fail, after bleeding there does not seem to be any obvious leaks and I get the brakes back -any ideas?

If the level is going down there must be a leak somewhere. I assume you've taken all the brake drums off to check the slave cylinders? Perhaps the master cylinder is leaking into the chassis leg?

If I were you I wouldn't risk driving the car until you've found and fixed the problem, because it may be about to fail catastrophically!

If one of the cylinders is leaking the only way to reliably tell is by looking into the drum via the adjustment hole.

You often don't get any actual pools of fluid on the road or obvious leaks as the fluid gets splattered around inside the drum and sucked into the shoes.

If you cannot find an obvious leak at the wheels then check the master cylinder. They often leak into the chassis leg.

If you have a servo - suspect it is drinking the fluid. Clue sometimes is a puff of whitish smoke from the exhaust just after you use the brakes. The fluid is going somewhere - so if no servo then you must inspect all the cylinders including the master v carefully. Of course - some have had leaky remote reservoirs - if that's what you have - inspect it carefully too.

dunketh wrote:If one of the cylinders is leaking the only way to reliably tell is by looking into the drum via the adjustment hole.

Nope, not the only way. You can remove the drum and have a look
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Thank you all for your comments, as a complete beginner at this I will now have a look at all the brake drums, but how do I get to inspect the master cylinder on the drivers side? and is there a repair kit available?
Regards
Ray

Nope, not the only way. You can remove the drum and have a look

That would be the better way to check, but I'm lazy.

but how do I get to inspect the master cylinder on the drivers side?

Theres a cover bolted to the floor under your drivers side carpet. Unbolt the cover and take a look.
Not sure how you'd tell for sure it was leaking, I guess just look for an abundance of fluid around the cylinder.
Maybe check the brake pipes and chassis rail underneath, see if any fluid has run down over them from the cylinder?

and is there a repair kit available?

I think so, but a new cylinder is only £50 which isnt a lot for piece of mind.

how do I get to inspect the master cylinder on the drivers side

Remove carpets, and you will find a plate covering the Master Cylinder. I am assuming you have a remote fluid tank, so first thing to check is for leaks in the pipe from there to the master cylinder. The pipe fits onto an adapter at the rear of the master cylinder. At the front of the master cylinder, is a rubber boot, prise this off, and check for fluid leaking from the front of the master cylinder.

It's not worth fitting new seals to the master cylinder, as there will be corrosion to the bore, which will destroy the new seals in next to no time. So a new master cylinder is the best option. Not a nice job if the bolts holding the cylinder in place are still the 'correct' way round, as the right hand torsion bar gets in the way when removing them. We'll cover that later of you need to fit a new master cylinder.