Wheel Cylinder Size for KE70 with Brake Upgrades

[gjgnz]

I've upgraded the front brakes and master cylinder on my KE70 and need to know what size wheel cylinders I should be running. I've got RA65 front brakes and T-series drum rear end with a Pajero Master cylinder.

The stock setup is 13/16" master cylinder, 2" front calliper pistons and 13/16" wheel cylinders. With the upgrades I've now got a 15/16" master and 2 1/4" front callipers.

Do I need to go with larger diameter wheel cylinders to keep everything balanced or will 13/16" be OK?

[LittleRedSpirit]

What do pajeros run inside their drums? Id run that as the wheel cylinder size.

When i designed mine I chose parts that worked with the stock MC, so I chose Ra40 struts and fitted ae86 wheel cylinders in the drums on the F series and it all works perfectly with stock MC.

I dare say you are moving more fluid than a T series drum rear end would normally have pushed at it, considering the mc has the same piston travel but a larger piston diameter. Therefore the wheel cylinder you use will need to process a larger amount of fluid. I would assume the change to a 15/16 mc would need a change to a 15/16 wheel cylinder if the stock sizes are 13/16 and 13/16. If you used a 13/16th wheel cylinder you would probably find there was a tendency to lock the rear drums, which is fatal.

I found an amazing catalogue that lists a shot tonne of different brake parts and their hydraulic sizes. Ill see if I can attach it, Ive used it so many times.

File is too large, PM me and I can email it.

[gjgnz]

Thanks, PM sent.

My main concern is locking up the rears due to the change in bias caused by the larger front brakes. It looks like RA60's run a 7/8" rear wheel cylinder so that might be the way to go.

[LittleRedSpirit]

The similar era toyota drum wheel cylinders are a very common design with just different bores. If you control F the catalogue then you can find every entry with that size. Most cars have the bore sizes listed.