Converting ABS to non-abs MC questions

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Converting ABS to non-abs MC questions

July 23, 2005, 08:21:33 PM

I guess any of you that have put a turbo coupe rearend in another car could answer this question for me as well....

I've been having problems with my brakes lately. Apparently the pressure switch is bad, so I basically have no brakes. I don't think you can get a new one at the parts store and thus far I haven't found one locally, and I just need to get these brakes fixed (plus, it looks like the pressure switch is a HUGE pain in the ass to get to and might even require removal of the MC).

So, I've been considering converting the car over to a stanard non-abs MC. I found that I can get an '86 SVO MC & booster for around $120 at advance auto parts. I read the article on this site about swapping in a turbo coupe rearend, so I know that I need an aftermarket proportioning valve and that I need to gut the factory one. I'm curious about a couple things though.

1- Why won't the factory proportioning valve work if you do this swap, even on a car that didn't originally have ABS?
2- Where can I take vacuum from for the MC? I do know that the line's supposed to have a one-way check valve in it or something, I'm guessing this is probably important since I have a turbo car.
3- Somebody on turboford said he did the conversion and had to change his brake pedal?

If I'm forgetting anything, or if anyone has any hints, let me know! I need to decide what I'm doing soon because barely having brakes is not fun. (I posted this in the wrong forum a few days ago...woops!)

Re: Converting ABS to non-abs MC questions

Reply #1 – July 23, 2005, 11:54:12 PM

Quote from: Red_LX

1- Why won't the factory proportioning valve work if you do this swap, even on a car that didn't originally have ABS?
2- Where can I take vacuum from for the MC? I do know that the line's supposed to have a one-way check valve in it or something, I'm guessing this is probably important since I have a turbo car.
3- Somebody on turboford said he did the conversion and had to change his brake pedal?

If I'm forgetting anything, or if anyone has any hints, let me know! I need to decide what I'm doing soon because barely having brakes is not fun. (I posted this in the wrong forum a few days ago...woops!)

#1 it will with no problems (drum rear cars gut the valve)

#2 off the vaccume tree on the firewall tee of the cruise if it dont have a nipple blocked off.or anywhere after the throttle plate

#3 i would'nt see that being a problem i have a parts car that was changed to a 5.0 set-up and has the factory pedal and it fits fine

Re: Converting ABS to non-abs MC questions

Reply #2 – July 24, 2005, 12:51:34 AM

So I DON'T need the aftermarket proportioning valve...SWEET. That saves me $40 right there. So that means I don't need to buy that pipe plug for the prop valve right? (just making sure I got everything straight in my head)

All the "nipples" on my tree are taken up at the moment so I will have to tee off the cruise vac line then.

Sweet, I got this whole thing pretty much figured out, now all I gotta do is actually buy the MC and booster. Thanks for the help! I've got some 73mm front calipers I'm gonna throw on the car while I'm in there too.

Re: Converting ABS to non-abs MC questions

Reply #3 – July 24, 2005, 12:53:01 AM

Quote from: SLEEPER T-BIRD 87

#1 it will with no problems (drum rear cars gut the valve)

#2 off the vaccume tree on the firewall tee of the cruise if it dont have a nipple blocked off.or anywhere after the throttle plate

#3 i would'nt see that being a problem i have a parts car that was changed to a 5.0 set-up and has the factory pedal and it fits fine

#1, actually, we have to run an adjustable proportioning valve, because the gutted proportioning valve would theoretically then send full pressure to the rear brakes, causing them to lock up way easy

#2, you could probably branch off of that big fat line that runs from the intake manifold, if you get a vacume booster from a non-abs car, they have the check valve sorta mounted on the side/front

#3, factory pedal will work, as far as i know

Re: Converting ABS to non-abs MC questions

Reply #4 – July 24, 2005, 01:32:52 AM

I thought he meant that the factory proportioning valve would work as-is, i.e. no modification needed. Which makes sense to me since the car already has four wheel disc.

Re: Converting ABS to non-abs MC questions

Reply #5 – July 24, 2005, 02:01:21 AM

I have the stock parts you need to do the fix for $50 plus $20 shipping. I used a longer pressure line so you have to use the one you have. It work fine until I took it off a couple of weeks ago to do a manual brake conversion.

tmdunlap@comcast.net

TED

Re: Converting ABS to non-abs MC questions

Reply #6 – July 24, 2005, 12:33:59 PM

Quote from: Red_LX

I thought he meant that the factory proportioning valve would work as-is, i.e. no modification needed. Which makes sense to me since the car already has four wheel disc.

yes exactly what i meant use an 87-93 5.0 mustang or 87-88 5.0 t-bird master and booster they bolt iin fit with no prob

the 87-88 t-bird's only use a splitter bock for the front brakes "prop valve" the rear brake line connects to the master as shown in pics

it is a fairly easy swap and straight forward. i have also set up a friends 84 5.0 with a 87-88 turbo coupe rear the same way stops fine with no premature lockup

here are some pictures

Re: Converting ABS to non-abs MC questions

Reply #7 – July 24, 2005, 01:11:50 PM

cad-t-bird- All I see in that pic is the MC and the accumulator. My problem is with the brake pressure switch next to the motor.

Plus, if I have to take the MC out just to replace that stupid switch I think I'd rather just convert the whole system.

Also I didn't know the rear disc brakes had a seperate line...how can I convert to a 2-port MC like the SVO unit? Would I have to attach the rear brake line to the gutted factory prop valve and tee the two front lines off the other port on the valve, kinda like how a Mustang's brake lines are set up?

Re: Converting ABS to non-abs MC questions

Reply #8 – July 24, 2005, 06:34:25 PM

The pressure switch is part of the motor and the picture is not the best. Having problems with my USB right now so I can't send you a better one.

You can take out the motor and switch without taking off the master. I did it in order to move it. If this fixes your problem it would solve a lot of problems.

In order to put on a different master you need to cut you front brake lines after the distribution valve and put in a "t". I found instructions on how to do this on the web but I can't find it right now. When I do I will post the link.

TED

Re: Converting ABS to non-abs MC questions

Reply #9 – July 24, 2005, 08:35:20 PM

I found out a little while ago while looking at my car that the brake lines are run exactly like the mustang, they just run across the k-member rather than along the firewall. I found that page online that tells you how set it up. So I think I'm gonna see if I can find a used booster from a 5.0 mustang and throw a bigger MC in there, and just go ahead and convert the car and put on the 73mm calipers I have.

Re: Converting ABS to non-abs MC questions

Reply #10 – August 13, 2005, 04:08:06 PM

Quote from: Red_LX

I found out a little while ago while looking at my car that the brake lines are run exactly like the mustang, they just run across the k-member rather than along the firewall. I found that page online that tells you how set it up. So I think I'm gonna see if I can find a used booster from a 5.0 mustang and throw a bigger MC in there, and just go ahead and convert the car and put on the 73mm calipers I have.

have you started swapping it yet?

i have some pictures now of my conversion to a old style 2 line master

Re: Converting ABS to non-abs MC questions

Reply #11 – August 13, 2005, 04:10:06 PM

here ya go maybe these will help some

Re: Converting ABS to non-abs MC questions

Reply #12 – August 13, 2005, 05:49:57 PM

No I haven't started the swap yet. Gonna do it on the 21st probably, I only just found a booster and I don't have it yet. I already know how I'm doing the lines though. The worst part is gonna be getting the old MC out... :disappoin

Re: Converting ABS to non-abs MC questions

Reply #13 – August 13, 2005, 06:23:29 PM

Quote from: Red_LX

. The worst part is gonna be getting the old MC out... :disappoin

yeah after you unplug the harness it isnt that bad just be prepared to use a 14 mm wrench because it is hard to get anything else in there and also helps a ton if you take out the seat!!! took me about 30 mins to take it out and 4 days to get the seat out

because the power motor had burn't up

good luck with your swap and if ya need any help dont be afraid to ask! :deal:

Re: Converting ABS to non-abs MC questions

Reply #14 – August 13, 2005, 08:47:53 PM

Oh I'm definitely taking the seat out, I can only imagine how many places I would hurt if I tried to get up under that dash otherwise (and it doesn't help that I'm 6'4" either)

Also...I think getting the old brake lines off so I can remove the master cylinder may be tougher than removing the MC itself. Not much room to work over in there.