Wilwood Master Cylinder Install

[tlorber]

I thought I'd post some information on a new Wilwood MC (model 260-8794) that I just installed. I know that some of this ground has been covered but I ran into some things that were not covered so I thought this could help clarify. Also, its one of the few times I had my camera so I took some pics.

2 months ago I replaced the brake booster on my '73 (which has an 8.5" booster and the front brake reservoir in the rear, rear in the front). At that time I noticed some seepage near the MC's plunger seal, so I thought I'd swap out the master. Since I don't have time to upgrade the brakes now, but I want to in the future, I figured the excess fluid capacity would be a benefit as well. One of the items the conversion calls for is that you need to change over the brake line inserts from your original Master Cylinder. My understanding was that for a Tokiko or Napco this would not be a problem. However, the insert on my Tokiko (the one on the right) was nowhere close to the one required.

Fortunately a guy around the corner from my shop had an old SANYCO MC and he was nice enough to pull them off for me. DO NOT START THIS PROJECT until you have the inserts ready.

First off, the new MC is nice and very close in configuration to my original. While the bleeders are on the opposite side, the Wilwood has the ability to reverse the bleeders to the OEM side for the early Z's. You just have to remove the set screws (each of which is retaining a ball bearing that seals off the port) and swap them over to the other side.

You have to elongate the mounting holes by about 1/16" on the top and bottom, but this is easily accomplished with a round file and/or dremmel.

One thing that concerned me a bit was the gap between inner diameter of the the base plate (or what ever the diamond shaped aluminum plate with the 4 holes is called) and outer diameter of the MC. On the original they fit snugly-(sorry for the blurry pic).

I happened to have in my garage an old 1 1/4"copper Tee that I had pulled off of a water regulator. This had nearly perfect inner and outer diameter to take up the space. I had to sand a bit on the outer diameter, but it ended up providing a very slight interference fit with the base plate-which is good to prevent it from slipping out into the booster.

All said and done, it went back together fine. I hooked up the brake lines, bled the MC with a plunger, and then hooked it up to the booster.

The pedal feels good. Mathematically I should be pushing about 30% more fluid, (requiring 30% more effort and 30% less travel). It does not feel all that dramatic, but I definitely like the less travel than I had with the stock MC. I will probably do one more bleed of the MC and the calipers but it already feels much more solid than before.

Edited March 28, 2013 by tlorber

[Travel'n Man]

I've got a 15/16th MC in storage for a later date - this makes me think the later date might be soon.

What are you plans for front / rear brake setup?

Great post - thanks for sharing.