i have a bad powermaster3 and i really dont want to pay 500+ to get a rebuilt one so i want to change it over to a regular master cylinder with a brake booster....how do i go about doing this.....some one please help!!! What parts and what steps are necessary??? thanks!!! Sean Lucas
If it were that easy, who would pay $500 for a Powerturd.
You will need to figure a way to attach the normal vac booster to the firewall. This will probably be by sectioning the firewall of the donor car and bolting it to the TGP. You will need to run new lines since the PMIII is a front rear bias, and the vac booster uses diagonal split. You will need to shorten the pushrod accordingly. This has been done by welding a piece of the new rod to the old rod. Finally hook up the vac line to the back of the plenum.
Chris
sounds fun, but it does sound like it can be done!!! I think there would an alternative to running new lines. Which ones were you talking about and why? wouldn't the front and the rear brakes just attach to the new master cylinder? For examle....what if i got the ABS system of a pontiac sunbird, will all the wiring match up? would anythng else have to be changed? oh yeah I forgot to mention....the reason i am changing my PM3 is because it is leaking....is there any replacable part on it that could be leaking that i could change, instead of changing the whole unit? thanks.... Sean Lucas
The brake lines need changed cause on the PMIII there is only one line that runs to the back and it splits into 2 there. The other setup has two lines going to the back from the master cylinder.
The sunbird system won't work because it hangs out and down lower and the abs will hit the turbo. A camaro uses a remote mounted versoin of the Bosch VI abs (sunbird and many many others). This could be used inconjunction with the computer for a newer w body that uses this abs sytem. Reason? The camaro has 3 speed sensors, a grand prix and tgp have 4. Most of the wiring for the powermaster would have to be junked. Ideally you can probably use some of it to interface the new computer to the abs hydraulic unit. the speed sensor wiring and a few other things can of course be reused. Also, the camaro abs system has 3 hydraulic outputs, two front one rear, just like the powermaster. So the lines wouldn't have to really be changed, just rerouted and adapted. And its not a neccesity to change the front lines if just going to vacuum brakes, but everyone I've talked to who has done it replaced the lines.
THis is about the only reasonable option I've seen for abs/vac conversion.
Some have recommended the newest abs used in the w-bodys and some other cars as it is smaller and integrated (i believe the control circuts are built in). But from what I can tell, these units are dependent on inputs from/to the PCM and may not work properly if they don't have a newer PCM.
Chris
well i decided i still want to have abs just not the powermaster3....what about the abs system off of a 1992 chevy lumina or berretta? Anything? any ideas? thanks.....Sean Lucas
Same deal. Almost all the mid to late 90's cars used some form of that abs system. I can't remember if its VI or IV, I think its IV since the one after that was Bosch V. You really need to find a standalone abs module. There are a few out there, but I think the remote abs IV will be easiest to implement.
Chris
okay...it sounds like you know alot about this......do you think you can do me a huge favor and do a little research and find out what i will need, where to get it and how to go about doing it? I would really apprieciate this i am young and learning i am only 16 and i am very interested in this car! My brakes dont work very well and i keep having to refill the master cylinder once a week....i wouldnt want to risk messing up the car in a accident because of a faulty master cylinder. the car is in pretty good shape besides my turbo needs to be rebuilt. please help....thanks Sean Lucas
well, i haven't done this myself. but like i said above the camaro one from a 1993-1997 ??? camaro should work, WITHOUT TRACTION CONTROL. Get the camaro master cylinder too, as it is close to the size needed and has 2 outputs vs the w-body 4. The w-body has 4 because 1 front and 1 rear are paired together for the diagonal split braking. Camaros came with either rear disc or rear drum. The master cylinder and abs are the same for either, but the difference is they put residual pressure valves in the brake line for the rear brakes on drum cars. RPV (residual pressure valves) keep the springs under tension to help adjust the rear brakes. You will have a choice to make for the MC resivoir. The w-body and TGP use a fluid level sensor to turn on the red brake warning light, while the camaro uses a pressure switch to detect a pressure drop in the line. If you want to use the fluid level sensor, you will need a w-body resivoir. It will fit right onto the camaro master cylinder.
You will need the firewall section and vacuum booster from any 88-96ish w-body, however, newer ones have a larger booster. This will make the brakes feel numb, but give you more stopping power with less pedal effort. If you want to swap in a 5 speed at any point, you can't use the bigger booster because it blocks the hole for the clutch master cylinder.
You will need to get the wiring diagram for the car you get the abs from and the tgp. Then you will need an abs module and the pigtail for the wiring connector from a similar year w-body. (in my example I have a 1994 camaro abs and a 1994 grand prix module). Then chart out which wires you can reuse (ie power wires, ground wires, indicator wires, sensor wires) and splice the old wires in to the new module connector. Of course this is after you remove your passenger seat and pull up the carpet to get to the PMIII abs module.
So you should now have the ABS unit, booster, master cylinder, vacuum line, abs module and all the wiring pigtails that go with them.
Find a place under the hood for the hydraulic unit. Anywhere will work, but you will have to run wires and brake lines to it, so try to make it as close as possible to the original stuff. I've seen abs EHU (electro hydraulic units), mounted on fram rails, in the trunk, OEM's stick them anywhere, and just have miles of lines and wires running to whereever they are.
I haven't figured out if there are enough wires going through the firewall to operate the abs hydraulic unit, but you will need to get the relay center for the abs from the w-body you get the module from . ONce you've determined which wires going through the firewall will be used (or added if you don't have enough), you can splice in the newer abs wiring and connectors.
Now run brake lines from the master cylinder to the EHU and from the EHU to the original TGP brakes and you should about have it.
This is what I've come up with so far and seems to be the most tangible remedy for removing the PMIII. It is by no means easy, and may not even work. It probably won't even be cheaper than replacing a PMIII, EHU's can be expensive. As always, I claim no responsibility if it causes an accident.
Chris
If the back of your pump is leaking you can buy that part from prior for about $260.00. This is where most of them leak.
Thank you guys and I apprieciate all of your help..now all there is left to do is make up my mind......I guess i will figure something out....thanks!!!
Sean Lucas
Quote from: sleeperred90tgpIf the back of your pump is leaking you can buy that part from prior for about $260.00. This is where most of them leak.
I had asked them about that once, and they said they wouldn't sell it. When did they tell you that?