The Stovebolt Site Forums The Shop Area Driveline 1956 on frame master cylinder brake bracket question

Ok guys I need to validate this story from a vendor. I have a 1956 Chevy 3100 step side with a 235. My VIN #3A56L-XXXXXX which Los Angeles is the assembly plant.

Current Situation:
I upgraded the master cylinder from the original to a dual master cylinder with a power booster frame mounted style. Purchased it from e-bay and I am just finding out that it does not mount correctly. My mounting nor does my master cylinder combo does not set level. I search one in the forum and another member showed me pictures of his and it does not set level either. I followed the instructions and I thought that was the way it was supposed to mount. Never thought any thing about it. mounted the bracket and had the bracket and the frame powder coated. I took a visit to Tucker's in Henderson NV and saw a little frame mounted example on display and it was level so I asked them if it was supposed to be level. Their answer was yes.

I asked the seller on E-Bay if it was supposed to be level and here is the conversation.

It should be level. Something does'nt sound right. I've installed lots of these and they were all level. The original bolt holes should be the same on all of the trucks. The booster should go flush to the bracket and the mc should mount flush to the booster.

(I showed him pics and asked if it looked right)
new bracket on original mounting bracket on the frame
MC Mounted

before powder coat
level on the frame
level on MC
old MC

It does seem to be too high. Not sure why either. After Christmas. See if you can get the measurements on the brackets where it bolts to the frame and we can compare them to these brackets I have here. My wife does remember that we had this problem once before and it was also on a 56. The holes in his frame didn't match up and he actually redrilled his frame. I guess you could shim the booster down if necessary. But lets check the bracket first.

bracket on frame measurements drawn

But after talking with a friend of mine he told me that one assembly plant in 56 actually drilled their holes different. Doesn't remember exactly (he is 86) but does remember something like that. I have only run into it one time also. Can't tell you any more than that. I checked a couple of different cases and all my brackets were the same. Probably over 7 years sold hundreds of them.

Here are my questions. Does that sound right about the 56 holes being drilled in different locations? If so wouldn't the original master cylinder be different from the other Task Force trucks? Does any one have any experience, comments, or suggestions? I know I can make it work but I must be missing something so any help or advice is appreciated. What I am worried is pedal location. If anyone has any bolt mounting measurements I would like to see if there is a difference. Thanks

Hy Tiny_Jaime, I think I have installed three of these type of setups for other people, in each case I had to modify the supplied brackets to make them lineup and mount properly. In at least one case I had to cut one apart and reposition and reweld it in order to make it work. I don't understand why there is such a radical angle between the bolt on piece and the booster mounting plate, that looks like where the correction should be made. I don't think that your friend is remembering correctly, as you said if one facility had a different mounting hole pattern/position how would the parts interchange with trucks manufactured in other facilities? If it were my project I would correct the parts so the top of the master cylinder was parallel with the top of the frame, hope that helps.

I have installed several of them including the one on my 56.
The only issue I can remember is that the pin was too large and had to use the old one. I didn't drill any additional holes in the frame or modify the bracket. I just looked at mine and it mounts parallel to the frame. My set up uses a larger dual diaphragm booster but that shouldn't make any difference. My truck was built in LA also. Perhaps the brackets were not welded correctly if so you may need to modify it to make it fit.
Fred

The only way the frame would be originally drilled wrong is a total goof up at the plant. They all use the same drawings and dimensions when manufacturing these things. That said, the after market made off shore parts are not going to be perfect reproductions of the OEM stuff or hole locations. That bracket looks to be way off. The new updated master cylinder should sit at the same level that the original single system master cylinder sat at. And never ever drill the frame, there is always a way to make a bracket that bolts on the frame to accomplish anything you wish to add on to the frame.