'66 CJ5 - Need Master Cylinder Filler Cap and Some Suggestions PLEASE!!

I decided to check the fluid level in the master cylinder, so I removed the access cover in the floor panel. Geez, what a place to put a master cylinder !! Well, I tried to turn the bolt on the top of the filler cap (it "seems" to be 3/4 inch) with a socket, but the socket kept slipping. Upon close examination with a flashlight, I found that the corners of the "bolt" are rounded. Probably because the darn thing is so difficult to access, whoever used to put in the brake fluid didn't have the proper tool, and boogered it up with whatever they used. Well, the work area is so tight that I can't get anything in there to grasp the boogered-up bolt and turn it. The only thing that will fit in there is the 3/4 inch socket on a socket wrench. So, I need some suggestions...

1. How to remove the filler cap with the "boogered bolt", and

2. Where can I get a new filler cap with that bolt built into the top - without having to buy a whole new master cylinder ??

 

There are a number of tools on the market for removing "rounded" bolts, and several of them are for use on the end of a ratchet. The ones I'm thinking of use either serrated teeth inside an oversized socket to grab the bolt head, or they use a series of pins hanging from the inside of the socket to envelope and grab the bolt head. Either work great and are readily available at a hardware or automotive parts house.

As for the cap, I would simply epoxy a large nut to the top of your existing cap. That has worked for me for several years

 

http://www.vernco.com/brakes/id262.htm

 

Well, I got it off. I was using a 12-point socket. Bad idea. I decided to try using a 6-point, but I couldn't find a standard set. Instead of going through 5 tool boxes to hunt down a set, I decided to try using a 6-point metric socket. 19 mm fit almost perfect, and it came right off. In fact, it fit so well that I'm not going to worry about trying to locate a new filler cap. And it did need brake fluid. So, I feel good about that little job. Glad I was able to "git 'er done" ! Thanks for the responses, I really appreciate it. You guys are always so helpful.

 

My 3-a has a setup much like the vernco idea.my original cap is drilled and tapped for a hose barb and a resivoir(sp) is mounted to the firewall.Love it!
Donnie

 

Sounds like a good idea. Trying to work through that access hole in the floor below the pedals is a pain-in-the-a**. Even more difficult is trying to pour brake fluid into the reservoir. I got it done though. I'm 6 feet 8 inches tall, so my hands are quite large. Kinda like a normal person trying to work with a baseball glove on each hand !!