9 replies to this topic

[Matt @ Surrey Hills Motor Group]

Quick Q for the techies....
Ive got a car in at the mo thats got that awful split diagonal brake set up. The master cylinder had gone so I'm looking at it as a good opportunity to convert it to split front /rear.
Apart from the obvious different master cylinder and requiring a pdwa valve, can anyone confirm if the original wheel cylinders would need changing too ? Drum brakes all round...
Thanks

[Ethel]

What are you changing the master cylinder to? By pdwa do you mean fam7821?

[KernowCooper]

Unusual to have a split diagonal system with drums all round ?

[Matt @ Surrey Hills Motor Group]

What are you changing the master cylinder to? By pdwa do you mean fam7821?

Changing from the split diagonal type master cylinder (GMC167), to the more common Split front/rear type (GMC227).

Yes the FAM7821

[Matt @ Surrey Hills Motor Group]

Unusual to have a split diagonal system with drums all round ?

the car I have in at the mom is a 1978 T reg - The system was used just either side of the crossover years until they realised the system was useless! ha ha

[Matt @ Surrey Hills Motor Group]

or has anyone had any "successful" experince rebuilding these particular master cylinders??

[Captain Mainwaring]

or has anyone had any "successful" experince rebuilding these particular master cylinders??

 

 

I did one about 267 years ago on my dad's S reg wood and plunket 998cc auto - I don't recall any issue - it's a master cylinder and needs taming....simple as that!

[minimanclive]

I converted my '78 diagonal split braked Mini to front rear split with front discs.  New master cylinder. FAM7821 valve, new rear brake back plates and post 1984 rear wheel cylinders. The locating pins are in a different place which is why I swapped the back plates.

[smev]

I'm looking at doing this on my 78 too, glad I found the thread. Was needing to replace the master and the pipes anyway, think I have found the right kit for that... So are the rear brake parts necessary and is that everything required?

Apparently there is only one back plate available these days so i presume the difference is resolved somehow. Is this the right wheel cylinder then? http://www.minispare...C1102.aspx?0401

[minimanclive]

The later back plate is the only one available now. The difference is the hole for the locating pin on the wheel cylinder.

If you're running the rest of the later system then it makes sense to use the whole lot.

 

If you had an adjustable bias valve then you could use any rear cylinders and adjust it to suit.