I need a small master cylinder with 7/8" bore
I don't think the front wheel drive MC has anything to do with the braking problems I'm having. There is absolutely none of the original brake system left on the car.
This K car MC has a 7/8" bore, which is the same as the Wilwood one it replaced and it performs exactly the same as the Wilwood one did.
I was just making a point as to why you wouldn't choose a FWD master if you were theoretically starting from scratch. A MC designed for a diagonally split system may work but also may not. Like I said the proportioning may be off since in a diagonal system, one reservoir handles one front and one rear wheel as opposed to a front/rear split master that supplies front and rear with individual reservoirs. In most braking systems, especially disc, the fronts do the majority of the braking so if you have a master designed for something different, then well, that could be your problem. Just food for thought. Get in touch with Ehrenberg or call Wilwood.
The front reservoir goes to a line lock then to a tee fitting then to the front wheels and the rear reservoir goes to an adjustable proportioning valve, then to the rear brakes.
Are you saying you don't have a distribution block? Might need one of those.
About the line lock - some will argue and say they did it the way you did it for years but you have it plumbed wrong. The line lock should be installed after the distribution block in the front lines. You are creating a situation where there is unequal pressure on both sides of the line lock. ((not enough where it needs to be) They way you know that this is a problem is if you get a brake warning light on when you activate the solenoid because the brake system is losing pressure on one side of the solenoid.
The prop valve in the rear line is also redundant and unnecessary. What size/type of brakes in the rear? If they are drums, are they adjusted correctly? Sometimes you need to have a smaller rear wheel cylinder to compensate for bigger brakes up front.
I believe the problem is with the pads and/or rotors. I either have the wrong pads or I failed to properly burnish the new pads even though I followed Wilwoods instructions on how to do that.
It's not the pads or burnishing them in. Unless you see that they are totally glazed over then I wouldn't be concerned with it. You have a pressure problem caused by an incompatible mix of parts and plumbing errors.
There is a third possibility and that is that the Wilwood brakes simply do not perform up to par, which is something I have heard other guys say. No matter what, I have to solve the problem and I'm going to do whatever it takes to do it, even if it means ditching the Wilwood brakes.
Never heard of anyone having a problem with Wilwood stuff. In regards to the other stuff, I am speaking from experience here because I went through a similar situation a few years ago. I have SSBC aluminum calipers, aluminum MC, Line Loc, adjustable prop valve in the rear line, stainless braided front lines and brand new 10 x 2 1/2" rear drums with 7/8 rear wheel cylinders. I bled them what seemed like 40 times but the brakes sucked. Hauling it down at the end of a run was downright scary. The line Lock would not hold either and it was plumbed correctly after the distribution block. I went to a smaller bore master and still not good. After that I yanked out the extra crap (Line Lock/prop valve) and things were better.
