Dual brake master cylinder install issues

I bought a dual cylinder master brake cylinder from Kaiser Willy, and am having some issues. I have the MC bolted into the correct place per the directions (if you can call them that). Problem is, when dry fitting the the brake pedal and plunger in the MC, the brake pedal sticks way out and there is now way that it could ever sit flush the floor pan when it is installed. The kit says to trim the plunger, but if I could trim the plunger down to a nub and it still wouldn't work.
It's like the MC needs to be pushed toward the engine a couple of inches, but I installed the bracket exactly where I was supposed to.

I have been in touch with Herm, and Kaiser Willy's. It just doesn't work. Any help?

 

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Here is the uncut pin. I have one that I trimmed the tip off of as well. Luckily I had 2 of them, but can anyone tell me what part of this I am supposed to cut? I took about an inch off the other one already. It seems that I could make it work better if I cut a section out of the the back part near the ring, and then re-welded the ring back on.


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I put Herm's kit on the '64 several years ago. The big problem I had was the rebuilt master cylinder. Got a new one and things worked. Sorry I can't help you with your problem. I think each installation has its own unique problems.

 

I take the two halves of the rod apart, cut the threaded end shorter, and tap new threads.

 

I was directed to Herm for help. From Herm:

It is all right to use the master cylinder to test fit for mounting purposes, but if you are depressing the plunger without bench bleeding you will damage the internals. Clamp the master cylinder into the vise to bench bleed using a large screwdriver instead of the rod, this way you will be able to measure the amount of the rod which is inside the cylinder when fully depressed. Taking that measurement and the outside measurement when released will give the proper length that you need. If you can not get full travel then you have damaged the cylinder by depressing the inside internals without lubrication

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Gotta love the response from Herm...I live near him and can tell you he is a good man and usually very friendly but its apparent you did something to tick him off...back on topic now...so the pushrod is too long? Its hard to tell from the pictures but when I did my last master cylinder swap I made a new rod using off the shelf hardware store stuff..cant you just cut it and weld it back together? You could even sleeve it for strength if you wanted..Have you searched this site? There has to be 5 pages or so relating to this swap, many with pictures. Sory your running into problems but keep after it

 

Yes, he is quite the character!

 

double check the mounting location of your master cylinder bracket. If it is too far to the rear, that might be the problem. I am in the process of converting, haven't gotten my bracket yet.

 

I thought about that, bu it is not possible to locate it anywhere but the correct position because the second part of the bracket loops over the brake and clutch mounting rod.

 

The part that needs to be shortened is the part that has the threads. Therefore you must take it apart, cut the threaded end, then either re-weld it, or re-thread it. After about 25 emails back and forth we came to this conclusion.

I understood it as the tip of the plunger needed to be trimmed off, which is what the directions lead you to believe.

 

I am right there with you somewhat. I have no peddle travel and my brake lights are on.

 

I ve been thinking of doing this job over the winter, but you re scaring me off. I thought it was a cut and dried procedure.

 

Sometimes and sometimes not.
One of the reasons I prefer hanging pedals and firewall mounted m/c.
That has its own set of challenges though.


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Sooo, anybody care to tell me what the "bench bleeding" procedure is? I have Herm's kit, but bought it years ago and what instructions there were are misplaced.

Does this have to be done on the bench in a vise, or can it be done while mounted on my chassis? I don't have the engine or body on the frame at all, just a bare rolling chassis, so it's all accessible. The brakes have been a brick wall stopping me, but I'm fixin' to hit 'em with a full frontal assault. I want over that hump, so I can move on.

Oh, and I'm assuming regular old Dot 3 brake fluid is fine? Or is there something else I should use?

 

Herm told me to put it on a table, in a vice, and use a phillips screwdriver to keep depressing the cylinder inside to get it bled. We will be doing it this week, so I will tell you how it goes.

 

Best way is in a vice but it can be in the chassis.
Make sure you put the flanged area where the mc bolts up in the vice, not the body. If you clamp by the body it can distort the bore binding up the piston. The piston should retract firmly and smoothly all the way against the retaining ring. If there is any hesitation on return the mc is junk and needs returned.


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OK, stupid question time....I'm assuming I need to fill it with brake fluid, and cap/plug the holes for the brake lines and sending unit? And the purpose of doing this is to distribute fluid throughout the M/C, and make sure it returns properly? Get it all wet and primed?

And back to the brake fluid question....Dot 3? Or something else? I haven't bought brake fluid in 15+ years.

 

Dot 3. Need to run brake fluid through the m/c and get the air out of the bore. A good way is to plug the brake light switch port and run tubes from the brake line ports back into the reservoir so when you release the mc pistons it sucks in fluid not air. Do a search for m/c bench bleeding on the Internet or on this site. Lots of info.


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You will not be capping/plugging the holes. You will be bleeding the fluid through them and out of the M/c. Plastic fitting are available for this and sometimes come with a new M//C. What you do is, thread in those plastic fittings (into the places where your steel lines would thread in to). Then, I usually use a piece of hose, from there, into a jar filled about 1/2 way with brake fluid, making sure the hoses reach well into the fluid in the jar. This allows you to watch the air bubbles coming of the M/C as you are pushing in on the piston to bleed it, and you won't suck air back into the M/C. When no more air bubbles come out, you're done bench bleeding.