I'll start at the beginning I guess...
This all came from a short, unexpected, unstoppable decent from a good friend's steep driveway in Longview
when I was leaving one day. I found that my brakes physically couldn't stop me from moving with some momentum...and it just had been getting worse and worse. I was looking for some good solutions for brakes -- and ultimately, after some research and a phone call to Van from VanCo brakes, I was given an idea. Van gave me some good options with his vacuum booster, hydrobooster or their Big Brake Kit. These of course are great products...and their reputation is very well deserved. Everybody I talked to has had really nothing but good stuff to say about the big brake kits and so on. But what he did tell me...was a less expensive alternative that would accomplish what I was looking for.
My 1993 YJ has a single diaphragm vacuum booster. In 1995 -- for one year with the YJ's -- they went to a double diaphram vacuum booster. The master cylinder's were close -- one is a 15/16" master cylinder and the '95 is a 1". The vacuum booster of course just adds braking power to the braking system -- and the double diaphram vac booster found on the '95 YJ gives a significant greater braking ability.
Part of the allure for this swap was the fact that essentially you can remove the entire mount/vac booster/master cylinder and reservoir assembly and replace it with the entire assembly from a '95 and it's "plug and play". Mounting holes are the same although the physical mounts are different. I got my entire assembly used for $100. Included mounting bracket, vac booster, master cylinder, and proportioning valve. Here's where we started:
Here is a couple of side by side comparison's of the two. My stock assembly is on the right, the '95 assembly is on the left. Notice the size difference between the vacuum canisters and the TJ style reservoir and master cylinder on the '95.
here are the mounts for the assembly..
notice that the arms that go through the firewall and hookup to the brake pedal are identical in length, shape and so forth.
Here is a picture from under and inside the firewall. You can see the hole the plunger passes through and attaches to the brake pedal on the stud...and my partner in crime monitoring my ramblings from the engine compartment.
Here's a picture of the clip that has attaches the plunger to the brake pedal. Don't lose it.
It just slips off with the help of a little leverage from a set of needle nose pliers or a flat screwdriver.
The most difficult part was getting the brake fluid lines from the master cylinder to the proportioning valve. We decided to use my stock proportioning valve instead of the '95 because mine was in almost perfect shape. The problem arose when we discovered there was ever so slight differences in the threads and such in both the m/c and p/v. We ended up having to get a couple of adapters and two 8" lines that Tim bent perfectly. I'll try and retrieve the part numbers for both the adapters and tubing from receipts...but we got into stuff so fast we threw tags and labels with that info. Here is a picture of the adapters and the bent tubing. Strong work Tim..
And...wa-la. One last comparison....
Much special thanks has to go out to my buddy Tim who helped me with this. I think the quality of work was excellent because of his efforts and the results were, well...frickin' awesome. See ya on the trail!
I found the receipt with the part numbers for the tubing and one of the adapters we used on the master cylinder.
From National Auto Parts, here is the #'s...
EDE318STA -- Brake Line $2.60
EDE338STA -- Brake Line $2.60
EDE271300 -- Brake fitting
The other fitting off the top of my head was like 265000...i'll have to see if I can find the othe # definitively. Hope that is some additional help, and happy wrenching!!