Oy, Need Some Help

So, originally I thought I cut the banjo bolt down enough that it would seal fine. Well, I found out that the threads were not exactly straight to begin with on the fitting, so when I pressed the pedal, the rear channel of the Wilwood tandem would shoot fluid out, but seal completely fine otherwise. I first started without the inverted seat on the inside, then tried with it on. Apparently it didn't take much until I bent the seat in a bit, and now it won't seal with a simple inverted flare tube. So, I tried calling Wilwood and they laughed in my face and said that the seat and fitting could not be obtained outside of buying another master cylinder. So, I come to you guys for any help and guidance in order to get this car on the ground. The brakes are the last thing before I can enjoy a drive in a car that has been on stands for over 4 years. If anyone can source me this seat, I'll pay anything reasonable and it will be greatly appreciated.

Here's a picture of the seat. You can see why it won't seal now.

Can I suggest that you go to a local machine shop and have them turn up a couple of replacements.

While you are there order two for me in case mine fail!



I had mine apart yesterday to remove the residual valves as recommended by Willwood.

Looks like you could just have it turned down a bit.

Well, I went and grabbed a set of SAE flare wrenches, torqued the nut down a bit more than what I could muster with the standard 3/8 wrench, and now it's leak free. I still think I need to replace it, but for now, the system seems to work fine and the pressure at the pedal feels great. I went for the 1" hole on the pedal and it feels just right. The pedal doesn't sink to the floor and no leaks so far.

Let this be a warning to anyone swapping this master cylinder in.

Anybody have experience or comments concerning bleeding a new brake system that uses a Wilwood tandem dual master cylinder?

Ya, it was a pain in the butt... I used a giant syringe to take the bubbles out of the master cylinder out of the bleed screws. I used a smaller syringe to inject fluid into the master cylinder thru the top at the small openings to get it started... Quite the operation.... lol

Can you identify the bleed screw(s) please.

Has anyone used a Motive power brake bleeder?

Yep, I use one, works great, especially on the clutch system, well worth the investment.

What fittings are you guys having problems with leaking?

I've primed new MC's before by the syringe method. On the Wilwood shorties, you can just fill the reservoir/s and leave the screw cap off (so no vacuum is created) then crack the bleed screws on the brakes/clutch and pull the syringe plunger for suction. Works a charm....

I hope you guys are not trying to plumb the factory bubble flare lines to the Wilwood inverted flare ports (should be 42 degrees)

Yep, thats what I used (the syringe)! The bleed screws are located at the side of the master cylinder.

I'm using short adapter lines that are Inverted Female one end to a Metric Bubble the other end.

Poly Armour PAA-0380 from Advanced Auto, part number 9140003 3/8"-24 to 10mm 1.0

To make life simpler and avoid these problems, I always use the shortest SS braided line with couplers (Concave to match the Convex "Bubble" in the case of the 944)

I always make sure I use the appropriate flare, I have tools for both. Our '88 Mustang uses both bubble and inverted flare, metric and standard fittings. Stupid Ford!

To Fliermike, That part you posted would not interface with the factory bubble flare lines. You would need an inverted bubble flare fitting.

Rob,

One end is 3/6"-24 SAE Inverted flare, the other end is a 10mm-1.0 Metric Bubble same as whats on the 944.

It's the SAE flares that's giving me trouble and leaking where it mates with the Wilwood MC outlet.

Wilwoods are 3/8-24 inverted flare, check for any cross threading, I found they were easy to thread wrong if you were not careful. I came close to screwing one up. Make sure the flare can seat before you thread the bolt in.

I'm seeing the same thing that Robstah reported, the conical seats are being chewed by the inverted flares. I'm frustrated by this and seriously considering Hydroboost.

I was just expounding on the fact that the Wilwood is supposed to be 42* straight angle, whereas the 944 lines are bubble (hemisphere/convex)....They would never seat. And if you use an adapter on the 944 line it had better be Concave (Inverted Bubble Flare) or it will not seat either.

Alot of trouble to get a better MC (more volume)....Why hasn't anyone tried the 928 MC? At least the lines would fit.

Sucks you guys are having such problems. I was told when I bought the wilwood Tandem MC to buy two 3/8-24 to 3AN banjo fittings and seal to the body of the MC with the aluminum crush washers. So I did and it worked great.

So, im not sure (you'd have to call wilwood), but my fittings dont exactly (or critically) seat to those conical seats within the ports.

Knowing Ford does some M10 x 1.0 lines.... check what I dug up....

Raybestos #MC390525.... 1" and both ports are bubble flare.

Guys, I have all the flaring tools and made sure that the new hard lines had the proper flare where needed. With that said, everything seems to fit fine and I was successfully able to bleed the system. Next step is to fix the plate flex that seems to be the issue with a 1/8" mounting plate.

I have never struggled as much as I did this weekend with the Wilwood Tandem MC.Today I installed brake bleeders in the MC side ports, removed the air and the system finally woke up. All I have to do now is to stop the rear port (front brakes) leaking at the tube nut .Almost impossible to get on the nut with the front port pipe in place. First time I ever had to bleed a MC.