M38 Master Cylinder

[Richard Whelan]

An update to those who may be interested in how this turned out. I am using Dot 3 for fluid. After not being able to get to my jeep for a couple of days. I decided to first use the test to crack the line at the master cylinder to see if the vacuum if indeed that was the problem would release the piston allowing it to travel normally. Well I did not need to go further. The piston is even slower today than it was when I first posted my problem.

So I removed it and benched tested it without fluid and the line ports open and the problem still occurred. So the problem is still in the master cylinder. I could try and bore it out a little more but I am afraid it will start leaking. After toiling with this beast for about a week I think it is time to move on and get me another.

Thanks for all the advice. Even though I could not resolve this it was indeed a learning experience I don't want to repeat.

Richard

[rob love]

Personally, when it comes to brakes and the time that can be spent trying to remedy a problem cylinder, I just put on brand new. Besides my personal collection, I also maintain a fleet here at the museum. I have not rebuilt a wheel cylinder since I came here....always brand new. It's cheaper than the labour and far,far more dependable.

The only time I actually even dis-assemble a master cylinder is when I am converting M35 master cylinders for use on M135s. A check valve has to be removed to make them work on that application.

In my experience, a rebuilt master gets you about 4 years, and a new one 7 years or better.

[Richard Whelan]

Not sure where to post info like this but for those looking for a Master cylinder at a good price. After spending some time trying to find a new Master Cylinder I found one through a company called Dorman and ordered it through Canadian Tire. Total price 55.00 Plus tax. It is the best deal around as far as I can see. You can order them on Amazon for as low as 63.00 CDN with free shipping. They sound like they specialize in this area and might have other hard to find Master cylinders for other vehicles.

Richard

[rob love]

I suspect a lot of these cylinders are made in China, and the various companies put them in their own boxes under their brand names. Dorman is one of the better priced companies I have found. I use them for the Ford CMP wheel and master cylinders.