Hi all

At current I have a Sierra master cylinder with a pitted bore causing a leak. Options are to replace it get it sleeved.

A new on is seeming to be the cheaper option but all the new ones I can fine all have 4 ports on them, one to each calliper I assume. My current master cylinder has 3 ports and has one line to the rear of the splits at a T before the callipers and 2 lines running to each front calliper.

I’m hesitant on using a 4 port master cylinder as I’m not sure if blanking one of the rear ports would have detrimental effects of the braking of the rear callipers ?

If any one could shed some light of the subject it would be greatly appreciated

Ryan

The Sierra master cylinder I re-used from my donor car had 3 ports.

2 (1 to each front caliper)

1 (split with a T to the rear drums)

Worked just fine.

Not sure what a 4 port master cylinder would be for - Sierra Cosworth perhaps?

Hi nick

Yes I have had the 3 port cylinder on the car since day one, and never had any problem . Now it’s pitted and needs replacing or repairing . But the only new ones I can find are the 4 port type. Just not quite sure how/why they are different or if they are compatible at all.

Or if any one knows where new 3 port ones are available from ?

Ryan

Ryan,

This one claims to have 3 ports:
https://www.kitspares.co.uk/index.php?route=product/product&path=43_9&product_id=80&car=43

Some master cylinders actually came with a blanking plug for any unused ports so blocking one off wouldn’t cause any problems

I'd simply blank off the spare port.

It won't cause any problems

Cheers Jon. I did see that one but obviously I didn’t read the description, just looked at the pictures. Oops.
And thanks for the confirmation rusty.
Cheers for the help and quick responses folks