Hello, I have been absorbing information from this forum throughout my entire build and have learned a lot from everyone, so thank you.

TLDR: H Series Slave Cylinder fits B Series Trans with just a rat tail file or rotary tool relocates bleeder and increases clearance between header

I looked for info on this and was only able to find one vague post.

If you have a B Series Header or turbo manifold that allows very little clearance to the bleeder valve on the slave cylinder and you want to retain the factory clutch hydraulic lines this may help you.

I had been chasing a clutch hydraulics issue that continued after replacing the clutch master and slave within 1000 miles of initial install, I properly bled the system and confirmed there were no leaks.

The clearance between my B-Series slave cylinder bleeder valve and header was no more than 5mm as seen below:



The header had to be dismounted in order to bleed the clutch system with a hose attached to the bleeder.

Symptoms:

• Soft clutch in hot weather under low speed conditions
• Occasionally the clutch would go straight to the floor after consecutive WOT pulls
• Dark fluid that quickly reappeared after a flush with fresh fluid

Diagnostic:

My first assumption was that the clutch master cylinder was defective. I removed it from the car and took it apart to find both seals intact and the piston in good condition. I cleaned it thoroughly and reinstalled it into the car.

I then moved onto the the slave cylinder in which I found the second seal to be torn, along with indications of heat and heavy wear on the piston. In this case there was no evidence of an external leak prior to removal.

Solution:

I purchased an H-Series Slave Cylinder and test fitted it to find the mounting holes to be slightly too wide. I then took my rotary tool (you could also use a file as it requires only a small amount of material to be removed) and evenly rounded out the insides edge of each hole to comfortably allow the slave to bolt up.

Here is a picture of the result:


Result:

Initially I was a big concerned that the pushrod looked a bit crooked. However, operation of clutch feels smooth and unchanged from the previous setup. The clutch fluid has remained a healthy color and there have been no instances in which the clutch has suddenly lost pressure.