I found that I have intermittent brakes on my 66. I have found brake fluid leaking from the back of the Master cylinder. Should be an easy fix, only one problem (had to be one. . right? A couple of owners ago added power brakes. It still has 4 drums, so I was wondering if one from the 73 F100 would work? I have looked at the pictures and it seems to match. The one from a 72 looks as if the lines come off the wrong side. Heres what it looks like. . . . Any Ideas? She's my driver and need to get her fixed, and the kids not big enough to ride in my sidecar yet.

Mickeyd

 

Went with the upgrade on both 65's and your setup looks same as the one taken out of 76 and 75 donor truck. Was not aware could put power booster with 4 wheel brake drums, although the upgrade usually does'nt include adding disc to rears. Not sure if MS would be same years because of the front brake drums, perhaps more knowledgeable member can advise. That being said, bought replacement master cylinders new for $44, no exchange necessary. from local Napa parts supplier, found they come with fittings on either side. Can get a rebuild kit $10-$15.

dave

 

Mickey, No, Do not mix the systems.

Dave, Doesn't the 73-79 mc have three lines coming off?


Another reason to buy a donor and swap, I know I can go to the parts counter and order any brake part for a 76 and be in bidness.

John

 

I think that jowilker means two lines ?

As for mixing the systems, I tried a booster from a 73-79 years ago it did not
work good for me, have you drove this truck with the 73-79 booster and (mc)
,and how did it work?

 

The parts places (online) I have gone too show 73 master cylinders with 4 drum as well as power brakes. I have the feeling that this is a 73+ by the looks of it. I doubt it is from another vehicle line.

 

John, as far as i know, there are only 2 lines coming off the MS, both go to the metering valve. Went with the upgrade, disc in front with shoes in rear, using donor booster and replaced the MS, hav'nt experience any problems. Believe same 2 line configuration from 73 to 79 but not an authority. Had experience with the Power steering upgrade using donor parts, was'nt any noticeble differece. The pump finally failed and after installing replacement it was like night and day. Donor pump was no good. After driving the truck for some 25 years with manual steering, the upgrade was like pure heaven.

dave

 

I've had a power booster on my `63 Uni for years with no problem. You can swap masters so long as the one you pick is for drum/drum.
Check out this link for more info on master cylinders...

http://www.mpbrakes.com/mpfaqmasters.htm

 

that looks like a disk-drum master cylinder because one bowl is larger than the other. Disks require larger volumes of fluid to push the larger piston. A drum-drum master cylinder should have equal sized bowls.

 

[QUOTE=instig8r63]
Check out this link for more info on master cylinders...

http://www.mpbrakes.com/mpfaqmasters.htm[/QUOTE]

Great link, thanks! I have looked enough at it and have decided to go ahead and change it out with a 72 dual drum brake master. I will probably change out the power booster at the same time and save me the problem of having to do it later.

Thanks for all your help

 

Damn! I wish I had that brake setup. The master cylinder in my F100 is a joke to say the least.

 

Yep had my head up my butt, 2 out of the master, 3 out of the porp. valve.

sorry

John

 

Most master cylinders have a casting number somewhere on them, usually the bottom. You may need to rub it slightly with sandpaper to make it more readable. This number can then be crossed to a replacement number. This should be no problem at a parts store that stiil has some books on hand. Good Luck!

 

I noticed in the picture that there is a proportioning valve right below the (mc) so it looks like someone has allready did the upgrade !

Just something I noticed that I missed the first time around !
A 65-66 does not have the plug that is in the picture or is this a TEST?





P.s the rear (mc) line has a little twist in it at the fitting!

 

I agree, looks like a Disk brake MC. I'm going to guess that you never need to change your rear brakes?

 

Well I had a few problems figuring out which parts to order. Lucky enought the local parts house had quite a selection of boosters in stock. I ended up switching to a 72 master cylinder. The lines had to come out the other side but that was easy enough to correct. I did have to get some different adapters for the lines and made one new line but it turned out good. But the 72 showed that it was for 4 wheel drum brakes, so I went with a new one instead of trying a rebuilt (only $10 difference). Of note, I have found out that a lot of the new M/C's are all the same out side with different valving depending on drum or disk. So just because they are diffrent size doesn't automaticaly make them for disk brakes.

The real hard thing to figure out was the power booster. It turned out to be a 73 with a non adjustable arm. We went through 4 of them before we found one that matched. Once every thing went on, I managed to kill one wheel cylinder (stuck bleader broke) so that added another trip to carquest and an extra hour fixing. It was amazing to see the gook that came out of the rear brakes while bleeding them. It looked as if engine oil was coming out, so another trip to carquest (good thing they are 5 minutes away) and more brake fluid to replace all the fluid. I found a line that started to leak after the change, since it was one I didn't work on I figure it must not have been use the pressure of a good M/Cylinder. So I was able to cut it down and reflair the tube and it held pressure. Then I was able to cut off to the test drive.

Well, the leaky line before should have told me something. I took it up to 20mph and did stomped on it. I now have a steering wheel bruise on the ol' belly. Totally different beast, I was able to lock up all 4 wheels, something I wasn't able to do easly (anything above 5mph) before. I get the idea that Big Red didn't have much on the brake since I got him.

Ron

PS:Pro-street, Im not sure what plug you are referring to.