Brake MC question

[Pylons]

Working on my MkIV complete kit. I've got 2 different size brake master cylinders: 0.75 and 0.625. My simpleton mind says the bigger one goes with the bigger front brakes, but I haven't seen confirmation of that anywhere. What's the deal?

Also, I'm assuming that I want the front MC inboard on the pedal box since the wilwood instructions for the balance bar seem to indicate the front is the one you want to do your adjusting on...that one seems like it'll be easier to access in the long run. True?

[CHOTIS BILL]

It seems to me I have ¾ inch MC for the front 6 piston Wilwoods and ¾ inch MC for the rear 4 piston Wilwoods. It doesn’t matter which position the front or rear master cylinder are in the balance adjustment is done with a threaded rod that connect the two together.

Bill Lomenick

[Pylons]

It seems to me I have ¾ inch MC for the front 6 piston Wilwoods and ¾ inch MC for the rear 4 piston Wilwoods. It doesn’t matter which position the front or rear master cylinder are in the balance adjustment is done with a threaded rod that connect the two together.

Bill Lomenick
isn't the balance done more with the relative lengths of the threaded shafts going into each MC and the rod that connects them just allows you to ensure that the MC shafts stay properly aligned?

[CHOTIS BILL]

No. The balance is achieved by moving the fulcrum closer to the master cylinder you want to apply more pressure. The rods to each master cylinder is used to adjust the height of the brake peddle and to adjust the balance bar to be square to the master cylinder rods when the brake is applied.
There is a full description on the Wilwood site.

Bill Lomenick

It took me a little while to find the info but check this out.

http://www.wilwood.com/TechTip/TechPedalTip.aspx

[teesalmon]

Hi guys,

Was there a conclusion on which master cylinder is for the front brakes, and which is for the back? I have done detailed brake balance calculations for the roadster assuming different frictions and CG heights, but I did these considering equal pressure to the front and rear. I realize the balance bar can be used to adjust brake bias. Without unearthing and studying what I did about 1 month ago, I want to just guess and say the larger is for the front so it will displace more volume for a given stroke to extend all six pistons in the front. Since I am not running brake lines today, it is not a huge deal, but I have to believe one way may be better than the other, maybe for no more than brake line routing.

Your thoughts would e appreciated, I will search the forum a little longer.

[Its Bruce]

3/4" front
5/8" rear

'Per FFR.

[CraigS]

Its Bruce has it correct.