Master Cylinder Replacement

[D-Dubya]

No responses on previous thread so I will try again. Has anyone had to replace the Wilwood master cylinders after the car was completed? My clutch MC failed and I am going to replace all three with Tiltons. Any advice, tricks, special tools, wisdom??

[OB6]

I did the same thing without the body on, so I don't think I have the insight you're looking for. Good move though.

[BornWestUSA]

I just replaced my Clutch master.

I loosened the pushrod jam nut thru the access panel above via the engine compartment with a stubby wrench.

I lowered the fuse box and removed the left end of my dash for access (not a FF dash, custom)

Then remove the reservoir and clutch slave cyl lines from the clutch master, (I vacuum bled out all the fluid via the slave cylinder first)

Then remove the two nuts holding the master to the pedal box

Then unscrew the master cylinder from the clevis, have rags ready, it will still leak.

On installation of the new clutch slave I had to prop up the clevis "level" from above to get it to line up with the master cyl pushrod.

[D-Dubya]

Thanks BornWest,

I had a slow day at work so I went out and decided to make a go of getting the MC's out today. Took me about and hour and a half to get all 3 MC's out with the dash completely off. I did not lower the fuse box, but I can see where that might be helpful. Followed basically the same process you described and, while it was a bit tedious and slow, it wasn't as bad as I had expected. Waiting for new Tilton's to arrive (hopefully tomorrow) to start the process of getting this back together.

A good set of "crowfoot" wrenches would have been very helpful. I would also recommend hiring a very small, very strong trained monkey as it is a tight squeeze through that access panel opening.

I only have about 2500 miles on my MKIV so I was a bit surprised at what I found when I broke down the clutch MC. The seal closest to the pushrod was definitely collapsed and the piston had some major abrasions with matching abrasions on the inside of the bore. The fluid that came out was almost black.

[BornWestUSA]

Please post a follow up, pictures of old and new master cylinders side by side if possible before installation.

The new Wilwood m/c I installed was just a bit shorter from the mounting flange to the slave hydraulic line location of my 12 y.o. one, but still workable.

My old Wilwood m/c's are silver / cast aluminum. the new one looks to be powder coated black aluminum.

I'm curious if the Tilton have exactly the same dimensions as the Wilwoods for future reference.

[Mike.Bray]

The Tilton master cylinders bolt right in. You want the 75 series.

Only real difference is the Tilton is much higher quality than the Wilwood.

[Oshkosh Rob]

When I changed mine out, the line fitting is of different thread, it took a different top cap, and the hose fitting changed from 5/16 to 3/8 which changed bulkhead fitting and fitting on bottom of the reservoir. Chain reaction was a bit more than I expected.

[D-Dubya]

I haven't received the Tiltons yet. I will post when I get them and let you know of any differences.

[RogerDM]

I just replaced my Clutch master.

I loosened the pushrod jam nut thru the access panel above via the engine compartment with a stubby wrench.

I lowered the fuse box and removed the left end of my dash for access (not a FF dash, custom)

Then remove the reservoir and clutch slave cyl lines from the clutch master, (I vacuum bled out all the fluid via the slave cylinder first)

Then remove the two nuts holding the master to the pedal box

Then unscrew the master cylinder from the clevis, have rags ready, it will still leak.

On installation of the new clutch slave I had to prop up the clevis "level" from above to get it to line up with the master cyl pushrod.

Gonna pass this on to a friend. He's taking in this MK4 Roadster project once the new brake pads and tires from 4Wheelonline showed up.