I am at a loss to find a master cylinder cap I can use with a remote reservoir. Stock 1-1/4" bore F-6 cylinder.
Any ideas?

 

Be aware, the aftermarket master cylinder may not be the same as original. I am running an aftermarket MC on my F4 and would like to run a remote fill also. I have thought about brazing or welding a fitting into the MC top. I, too, am open for ideas and discussion.

 

Bob are you saying a stock F6 cap will work . Im looking to see if i have one.

 

8C-2162-A .. Master Cylinder Cap / Obsolete

1948/52 F1/F8 / 1953/56 C500/800 Cab Forward & P350/500 Parcel Delivery.

 

Bob, if you are looking for an original cap, I have some too.

 

Does anyone know the thread diameter and pitch?

 

I have a MC in the shop, I can measure the thread tomorrow. What would be needed to hook up a remote reservoir? Would a cap with a hose fitting or a threaded hole for a fitting work?
Mark

 

I would think so, Mark. Needs to seal tightly on the MC of course, so the wide flat flange is necessary.

 

I'll check it out tomorrow. A threaded cap with a pipe thread hole in the top would be simple to machine, unless the MC thread is odd.
Mark

 

Good question, as my new master cylinder is an aftermarket also. So I took the new (aluminum or pot metal) cap and tried it on the old unit, and the thread pitch and diameter (straight thread) are the same, so they are interchangeable. If I could locate a steel or cast iron cap I'd be in hog heaven.

 

I'm thinking as a last resort to use a pressure test plug, however I don't know about the compatibility with brake fluid, but knowing that steel and neoprene are ok, I'd probably go with it.

 

I think that cap has to be vented so you don't get a air lock. The treads are a normal
60 degree NF. I machined many of those from brass easy job but did drill a 60 thou
breather hole. You have a friend with a lathe then its a snap.......sam

 

This would be used with a remote reservoir which would be vented. I have access to a lathe but it's on a ship, so that's out.

 

Come to think of it, I could just drill and tap a 1/4 NPT hole in the top and install a barbed hose fitting, and seal off the original cap.

 

The threads on the cap of the Wagner MC that I have measures 1.230 O.D. x 18 TPI. The cap fits very loosely so the thread may actually be 1 1/4 -18. The sealing flange on the cap is 1.5 O.D. The cap would be very simple to machine.
Mark