Hi all.
The new master cylinder I put in leaks. I thought it was leaking at the o-ring for the switch, but it is leaking above that boss. I have no idea what is up there. It is not leaking from the filler tube (which is a single tube, EPDM hose and splits into two for the inlets to the master cylinder-special construction for the batteries in the car. The fuel tank is gone, and the entire well is filled with batteries).

Consequently. I hate to pull the MC back out. There seems to be some sort of allen screw or something (best I can tell by feel) on top of the MC.
Anyone got any ideas?
TIA
Pat

When you say the area where the fuel tank was is filled with batteries; did you convert the car to an electric vehicle???

Yes it is electric. 7 Tesla batteries and hyper9 motor. Fuel tank area is full of custom batteries I built for 72v air conditioning and 12v step down.Click to view attachment

I guess I can pull the MC out and see what the problem is.

Do take a close look at the rubber hose area. If it's leaking it will appear to come from that area.

Yup. it is leaking from the hoses where the resoirvoir feeds it. But, I pulled it all apart, and cleaned it with denatured alcohol. If I can find a sealer to dab on those rubber fittings, I'll be all set. Evidently. few products are compatible with brake fluid.

A little off topic, have you weighed the car to see what the balance is now from front to back? All those batteries look like it's nose heavy.

Make sure you have the washers in the inlet holes under the seals. Apparently the hoses are a lot more difficult to install with them in, but they will leak without.

--DD

Its about 2000 pounds. F/R is 1004/1123. And, it will spin like a top and not roll over. The Tesla modules are 55 lb each, I have three in front and four in back, in special boxes. The 72v/12v batteries are about 84 pounds.

And they must be new washers. IIRC they are aluminum or some other soft metal

Also check to see it's not leaking from the welch plug...

100% true...

Matt

This.

I have installed two in a row with that leak. Ran out of energy so this second one keeps up with a slow drip. ugh... maybe I will swap it out for the new ATE I have over Thanksgiving week.