Still have the problem with brakes ,everything is new or reconditioned. Now ,when you push the pedal a few times the pedal goes hard and the front disc brakes lock, after a few minutes they release, this is without the engine going. A good mechanic has told me when they resleave the master they partially block off the fluid hole in the master cylinder. I am now trying to borrow a mk 2 master cylinder so I can check if this is the problem. I live in the Newcastle area if anyone has got one that I can borrow. Any ideas ????
TY Allen

Did you have the master cylinder re-sleeved? If so, why not quiz the people who did the job what they did? My understanding is that the tank has to be removed to able the hole to be re-drilled.

the MC was resleeved

Was the hole re-drilled through the sleeve?

its easy to check... but check your private messages Allen

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did I tell you that I won a trophy?

Check the residual pressure valve in the master cylinder.
I had a problem recently with a MK1 master cylinder where some rust flakes from inside the tank were trapped in the valve and it wouldn't let fluid back into the master cylinder and the brakes wouldn't release properly. I currently have a plastic tank MK2 m/c fitted because that's what I had on the shelf.
I know its not the same type of master cylinder but the plastic tank type should still have the residual pressure valve fitted. If there is no residual pressure in the brake lines then you can get air sucked into the system through the drum brake wheel cylinders. The residual pressure keeps the wheel cylinder cups expanded. The valve is essential for any car that has drums or disc/drum combination brakes.
If you have a split system master cylinder you still need the valve in the line to the drum brakes. It may be the cause of your brake booster problem from your earlier post.

RonR

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68 build Mk1 Cooper S
72 Clubman GT project. Total restoration required

Are you using plastic m/c or tin tank?

plastic tank, is miniron correct? I was told by the brake place they do not have a residual valve when there is disc brakes.
Allen 1970 mk2 c.s

The manuals calls it a non return valve to prevent a loss of fluid when parked on an incline. But it is more like a slow return valve or a residual pressure valve.

It does help to keep the wheel cylinder seals expanded and it does help to keep air from being sucked in and it also helps when pumping up the brakes.

I can only find the tin type reference at the moment.

My understanding is that brake drums are not always perfectly round and any ovality can cause the brake shoes to move the wheel cylinder pistons slightly back and forward and in the process air can be drawn into the wheel cylinder by the movement if you don't have a residual pressure valve. The valve only maintains a few PSI in the brake lines.
It may well be to prevent fluid flowing back to the master cylinder but only if the car is parked on a steep incline with the front pointing downhill and then only if the rear wheels were higher than the master cylinder, but I am still willing to learn.
If you don't learn something new every day you are not trying.
Disc brakes don't need the valve as they have a different type of seal which doesn't rely on the wheel cylinder cups being expanded slightly.
There are at least 2 types of residual pressure valves, one is a rubber type and the other is a white plastic type with a circular spring steel strip around it.

RonR

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68 build Mk1 Cooper S
72 Clubman GT project. Total restoration required

I really think that you should find another brake specialist...preferably Mini savvy...there is something that they haven't picked up and/or are not picking up.

Ask your local Mini Car Club for recommendations...cut your loses and avoid a failure or expensive accident

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does anyone know a brake place that may do minis ?I seem to be going around in circles, they may have an answer otherwise I will buy another master cylinder, the current mc cost me $175 for the reco.
TY Allen

There is a brake place at East Maitland, have you tried them?

The old bloke at my local brake place has been in business since the beginning of time, he knows all of the old stuff. I guess my offer to you works in the opposite direction too, send it down to me and I can get them to sort it and I'll send it back

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did I tell you that I won a trophy?

He would've resoled Fred Flintstones shoes a few times then?

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ex-NSW Police 1970 MK II Cooper S
VMCI #43