abs to conventional?

is it possible to remove the abs master cylinder and put a conventional power booster and master cylinder on a 1990 bonneville or am I grasping at straws

I stumbled across an article that gives some details for converting the TEVES antilock system to a conventional vacuum assisted system. This was written by a Trofeo owner but should be very close to the Bonnevilles:


THE BRAKE SWAP by Garey.

http://img204.exs.cx/img204/1984/nonabs2hb.jpg

The brake swap was pretty much as simple as replacing the master cylinder and brake booster but it did have a couple of catches, doesn't everything?

The only somewhat tricky thing to the swap was the missing fourth brake line. The Anti-Lock Teves models only have three brake line coming off of its master cylinder, one to each front wheel and a single line going to the back two wheels via a splitter located near the left rear wheel. The splitter will need to come out and a coupler installed in it place so that line can be dedicated to the right rear wheel.



Now, the replacement non-antilock brake master cylinders require four brake lines, one to each wheel. So you will need to have a brake shop install a fourth line to the left rear wheel or you can obtain one from a salvage yard Trofeo. This method is cheaper and can be done your self. Either way it will work. Just don’t kink the line removing it from the donor car or it trash.

The original brake lines mount to the underneath side of the Teves Unit. When the Teves system is removed by removing the four bolts under the dash you will see three brake lines pointing upward in the engine compartment. The Teves System is really heavy so you may want to have someone hold it while the bolts are removed. Take care not to kink any of the three lines, as you will need to reuse them. They will need to manipulated into a 90-degree position facing the passenger side of the car in order to meet up with the new master cylinder, which will require a little work. Take your time here. The last thing you want to do is kink the lines.


Once you have the fourth brake line installed and the splitter removed from the third brake line and a coupler connecting it to the right rear wheel line at the rear axle, you can now prepare to install the new Power Brake Booster and Master Cylinder but there is one more thing to take care of and that is the brake pedal.



The Antilock brake pedal itself has a larger diameter-mounting stud for the Teves master cylinder to connect to. The new non-antilock booster will have a smaller eyelet opening and will not fit the Antilock brake pedal. So, you have two options at this point. You can use a drimel type tool and enlarge the opening on the new brake booster eyelet to accommodate the antilock brake pedal or you can obtain a non anti-lock brake pedal from a salvage yard Trofeo just like the brake line. You can also purchase one at a dealer but that might run a little money. You will know the non-antilock pedal because it won’t be stamped “ANTILOCK” on the face.

The brake pedal is removed by a removing the single nut and 2” bolt under the dash panel that passes through the pedal arm.

Oh yeah, the several power and signaling cables that hook to the Teves system can be taped off and secured out of the way. I don’t advise cutting them off because it could set a code. The antilock brake computer in the trunk can be left there as well. Again, it could set a code if removed. It didn’t bother me at all to leave it there.

Once your done and everything is back together, the new master cylinder itself and the brake lines with have to be bled thoroughly to remove all of the air in the system otherwise you will have no stopping power. That is a two-man job. New Items for the Swap

Both are from a 1989 Trofeo Non Antilock Model so parts are available.

1- Master Cylinder for the same model year.
1- Power Brake Booster for the same model year.

The Master & Booster sometimes come as a cheaper combo at some parts stores.



I think I'm going to have to give this a try cause I'm already unhappy with the braking performance and I'm swaping in a Series II L67. I'm going to need to do something...

thanks for the reply---I found one at a junk yard for 80 dollors---but what what a good idea if i would have had to buy one from auto zone 750.00-------

$80 is great! I've seen reman units for $1100 in my travels.

I'll let you know if I convert mine. I'm right at that stage. Glad you fixed the problem.