Mk1 front disc brakes which rear brake cylinders

[Rockinronnie66]

Hi recently purchased a mk1 with front discs fitted but needs rear wheel cylinders replaced.

My question is what rear cylinders to fit ? They are 19mm standard bore I could fit 20.30mm bore or would it be better to fit mk2 23.8mm bore?

Thanks Ronnie

[Ollie]

Hi, I'm doing the same thing on my mk1, but in my case I expect to use absolutely everything from one van. in my case I'm fitting complete mk2 vented discs to a mk1 lwb

which van do you start with, short or long age etc, and which front brakes, bolted on single piston calipers or twin pots? and again from what model van? and finally which master cylinder do you have, or plan to have!

Ideally you want the rear cylinders to match whatever equivilent van your front brakes where fitted too, but if in doubt I'd allways go on the more conservative side to prevent locking up when empty.

[dumper]

Back in the day transits were a nightmare to get the correct cylinder sometimes we would fit what ever was available and if necessary we would adjust the L A V valve to suit if the efficiency was down or locking the rear brakes.