Bypassing ABS

[colindo94]

I am in the process of bypassing the ABS and I was wondering what line from the master cylinder goes to the front brakes and what one goes to the back breaks? Or does it matter at all?

 

[IZwack]

Just follow the lines, that should tell you.

But if you've already pulled the lines, the rear fitting goes to the rear, the front fitting goes to the front (I think).

 

[colindo94]

The lines coming from the master cylinder go into the ABS module and then 3 lines come out of that. One to the rear, one to the left front, and one to the right front. So I can't really fallow the lines.

 

[Burns]

Ah man Uh get a master cylinder off a non 91 and use the exsting lines to re do the system



This may be the long way around the question

 

[colindo94]

Why would I need a 91 master cylinder? I talked to a guy on rrorc and he said just use the hole toward the back of the truck for the front brakes and the hole in the front of the master cylinder for the rear brakes.

 

[Burns]

Well im not sure. I dont think you would becasue if im correct the lines go from the master cylinder to the abs junk right? If so just use you factory master cylinder and do it like that. Its how mine is from factory

 

[mawrazen]

All you need to do is disconnect one of the front ABS sensors.

 

[colindo94]

Yea I know. I haven't been running abs for months now. I just don't want all that junk anymore and I have to redo some lines up there so I figured I'd take it out now.

 

[justsomeguy]

I took my ABS modulator off, and I am putting on rear disk's. I put the front port of the master cylinder to the front brakes and the rear to the rear. I looked at a couple older EX's with out ABS and that is how they are configured. Has anyone put disks on and kept the stock master clynder? I tried to get a 95 with four wheel disk and it's the identicle master as the stock 94 master cylinder. BTY full width 44 and 9 inch in the back with Seville calipers.

 

[colindo94]

Huh? Have you driven it since you took the abs out? I plumed mine oppisitie to how you did yours. I put the front port to the rear brakes and the rear port to the front brakes. I havn't driven it yet so I guess well see.

 

[colindo94]

heres a little thread I found on rrorc
http://www.rrorc.com/forums/showthread.php?t=35322

 

[justsomeguy]

cool thanks for the info. No I have not driven it yet! I guess I got turned around some how. Thanks

 

[Diff Whack Daddy]

Does anyone know the size of the fittings on the side of the master cylinder?

Still not sure why you would reverse the front and rear brakes on the MC, anybody have anymore insight on that?

 

[fordnut71]

you want more brake power on the front then the rear.60/40 front rear.
when you push on the peddle the back port would be 1st to get pressure fluid ---so it will do the front the 60%
the front port will be last to get pressure fluid so it goes to the rear--- so that will be your 40%
its plumbed this way because when you brake your truck weight will transfer to the front needing more braking power on the front tires.
if you plump it the opposing way the rear will get 60% braking power on a lighter rear an the front will get 40% on a heaver front end --- so what it does is cause the back end to swing aroung on you.

 

[Diff Whack Daddy]

That's what I thought the purpose was, but the way these Master cyliders are set up, the front port is the one that recieves 60% of the breaking. Right now, mine is plumbed with the front brakes off the front port. When I mash on the brake pedal and step on the gas with the front axle only engaged, ie, rear axle in neutral, the rear tires still turn, don't lock up when the gas is depressed. They should drag as it powers through the front brakes. This is needed to do front digs on tight corners, and since I can't lock up the rear tires, even with the rear driveshaft dissengaged, my front digs are not nearly as effective.

Don't tell me it's a bad MC cause it's brand new, for a 95 to compensate for my rear disks. It did the same thing with the 91 MC. It's the way they are designed to allow more braking pressure to the front. The 91-92 with rear ABS were plumbed this way, the 93-94's with 4 wheel ABS were also plumbed this way (front fort of MC to front brakes) and the 95 and up with 4 wheel disk brakes are plumbed this way as well, so I think that by reversing the ports, you are reversing the brake biasing. The front port is larger to provide more volume as well, which is needed by the larger front brakes. Of course, the only true way to tell would be to put an in line pressure valve on each line to compare the true braking pressures.

My next step is to install a adjustable pressure biasing valve on the front line to allow for a little more rear braking to get the correct ballance. I am also going to put in hand controlled cutting brakes for the rears.

 

[IZwack]

^--- how about a line lock for the brake line going to the rear brakes?

http://store.summitracing.com/partd...part=SUM-760002&N=700+-46908+115&autoview=sku

 

[Diff Whack Daddy]

Yep, but I'm going to use this one to ensure there is no battery drain. Going to mount it directly in front of the cutting brake. Easy to operate.

Engage = Step on brake, push button, release brake.
Disengage = Step on brake.

 

[fordnut71]

back brakes never lock up if the car isnt moving. that how hot rods at the drag strip does a burn out.
if you are trying to make the back as tight as the front so you can a front or rear dig, then maybe you might want to use 2 single masters. its like what a backhoe an some road race cars use. you can make it 2 peddles hooked together with a pin for on road. off road you can pull the pin an dig front an rear.

 

[thjranger]

I am doing a SAS on my 94 with 4 wheel ABS, I would like to get rid of the whole abs system, I would like to know if this works ? and I also thought about putting a proportioning valve going to the back brakes. I thought you had to run the front line to the front brakes ? Will my existing MC work ? I have 96 discs in the rear and they worked on my 97 Ranger with the original MC.

 

[Diff Whack Daddy]

back brakes never lock up if the car isnt moving. that how hot rods at the drag strip does a burn out.
if you are trying to make the back as tight as the front so you can a front or rear dig, then maybe you might want to use 2 single masters. its like what a backhoe an some road race cars use. you can make it 2 peddles hooked together with a pin for on road. off road you can pull the pin an dig front an rear.

Wavin' the BS flag on that one. If their is enough pressure to lock up the brakes when the vehicle is moving, then there's enough to lock them up when your stopped and there is no power going to them. I didn't even have a rear driveshaft. They should have locked up and drug when I powered through the front brakes. I am well aware of how a hot rod performs a "power brake".

Even slamming on the brakes while doing about 15-20mph didn't lock up the rears, just the fronts.

My point is that I probably have about 80 to 90 percent braking going to the front and about 10 to 20 percent to the rear. This is why a proportioning valve is needed on the front brakes to reduce the pressure to the fronts to get a closer ballance of 60/40 front to rear.

I am doing a SAS on my 94 with 4 wheel ABS, I would like to get rid of the whole abs system, I would like to know if this works ? and I also thought about putting a proportioning valve going to the back brakes. I thought you had to run the front line to the front brakes ? Will my existing MC work ? I have 96 discs in the rear and they worked on my 97 Ranger with the original MC.

That is exactly what I did. Originally on my 93, I just left the ABS modulator in and hooked up the new axle. Never had a problem. When I rolled that one and swaped to the 91 frame and body, I simply bypassed the Rear ABS module on the frame rail. I have been running it like this for years and have never had any problems stopping, braking, etc...

The reason I am re-working the brakes now is to allow for front digs. To do this I have to disengage the rear axle, and step on the brake and then power through the front brakes. with the incorrect proportioning right now, I am unable to apply enough pressure to the rear brakes while powering through the fronts. Hence the need for the propotioninf valve to lower the front pressure. The cutting brakes will also help.