7 replies to this topic

[Tomlad]

My mini is a 1988 Austin Mayfair the brakes are a one pipe system but they were not connected when I got the mini the tee that connects the rear breaks up was missing. But I'm not sure if I will need just a standard 3 way union or a proportioning valve like this:

http://www.minispare...px|Back to shop

The mini has a 1275 engine with disks on the front and drums on the back.

Thanks for any help

[rally515]

Most people just converted it by putting the T-piece in its place not needed unless in concours really.

[tiger99]

It is not a proportioning valve. It is a pressure limiting valve, which is a very different and simpler thing.

As far as I can see, a 1988 model should have a dual line system with a PRV on the bulkhead. And yes, you do need something, otherwise the rear wheels will lock dangerously.

Edited by tiger99, 06 January 2013 - 09:59 PM.

[KernowCooper]

Yes my 1980 has a split system with a tandum upright master cyl split on the early ones like mine Front/Rear and had the pressure reducing valve on the drivers side going back into a T piece on the rear subframe. Yours being a 88 model should be a tandum system and not a single line like the earlier minis, without a pressure reducing valve the rear brakes suffer from locking up due to weight transfer under braking and lack of weight over the read axle. That was the main reason the battery was put into the boot to gain some much neded weight under braking

Edited by KernowCooper, 06 January 2013 - 10:04 PM.

[JVA10L]

The dual line brake system was introduced in 1976(ish) so your car should have that system. The single line system had the pressure regulator valve fitted to the rear subframe and it limited the amout of pressure to the back brakes to prevent the rear wheels from locking under hard braking. If you only have one pipe coming out of the master cylinder you will need a pressure regulator for the rear.

[Tomlad]

Ah cheers wonder why my mini has a single line? Do you think it would be best to put a tandum system in?

And thanks again

[KernowCooper]

Tandum brakes were designed as a safety feature if you lost pressure in one line you still had a brake force (reduced) in the other, which unlike a single was a total loss of any hydraulic brakes and you only had the handbrake left!

Lots of minis on the road in the earlier cars which are single line systems, if you are unsure which your master cyl is there was a danger on the single line systems where with discs fitted the master cyl didn't hold enough fluid when the pads wore down but that was the very early type.

best to have the correct bore master cyl as a match to the discs as this could affect braking performance, so in your case I would do the conversion back.

[Tomlad]

Right thanks a lot for the advise I will do just that