remove ABS from '94 Suburban?

[jimfulco]

On a '94 Suburban with ABS, is there any way to remove or disconnect the ABS so the truck will actually stop hard on dry pavement when you tell it to? I understand that pedal pulsation is normal for ABS, but the pedal going to the floor and the truck refusing to stop just seems wrong to me. A friend of mine had a '92 Sub and the same phenomenon caused him to hit the car in front of him. I'd much rather have old-style brakes with no ABS than a braking system I can't trust.

[apstguy]

DO NOT remove ABS. It is a main component of the computer control module. Suburbans are just too damn heavy for the brakes they put on them. The 90's Tahoes and Suburbans are known for having weak and spongey brakes. If you want better brakes put on high performance pads, put rear discs on it, or upgrade the rotors and calipers.

[jimfulco]

The brakes are not so much spongy as they are just plain dangerous. A bit spongy I could live with, and I wouldn't expect it to stop like a Porsche, but the pedal dropping to the floor & at the same time the truck continuing to careen down the road just ain't right. I don't know how differently its built, but my old '79 Sub stops just fine with stock brakes & metallic pads up front. The '94 is my dad's truck, & he's threatening to buy a new pickup & give me the Sub, but I don't want it if the brakes can't be trusted. I just need to know if it can be fixed, & if the ABS has to go, that's OK with me.

[Scrub]

I have a good friend that is in prison for murder because his Ford ABS brakes failed and his wife went of a 1000 foot cliff and died.

I don't trust ABS. As far as I can see the whole frikin' system could be bypassed and replaced with older brakes that really works. Why would a disconnected computer care about anything? Are the rotors or calipers any different?

Obviously there is something wrong with your system, but the cheapest and best fix may be to scrap the ABS.

Someone tell me why I can't just plumb around the ABS system

[apstguy]

Most ABS is plumbed and controlled by the computer in the truck. Without the computer, the truck doesn't work. The sensors for ABS are in the spindel and axle.

If your pedal is going to the floor, you have other brake problems, not ABS. Don't make it a scape goat.

Ford ABS brakes suck. We had an explorer. Something in the ABS would short out so everytime we hit a bump the brakes would go out. The dealership said nothing was
wrong

[jimfulco]

Chevrolet says there's nothing wrong with the brakes, has said so for years, although many people disagree. I think there were some lawsuits over it, but I don't know how they ended up. My dad & my best friend have both described the same problem, & my friend actually hit someone in the rear because of it. Neither of these two are "white-knuckle" drivers, quite the opposite. If they said the brakes failed, they failed. Both said the brakes worked normally after they let off all the way, it was just too late in my friend's case.

[Scrub]

The problem with most ABS failures is a computer crash, just like when your windows98 crashes. There is nothing wrong with your computer per se, just your software. same thing with the brakes. the software (really firmware) crashes and then you crash. The mechanic will tell you "Nothing is wrong with these brakes" just the same as nothing is wrong with your computer after you reboot it. fortunately having a mouse lockup is less tragic than a brake failure.

APSTGuy, what wouldn't work if I plumbed around the ABS? How would it know I plumbed around it?

Thanks

[apstguy]

Other components can be dependent on ABS. Tire pressure monitors, speed sensor, stability & traction control, ECM info, etc. You may be able to get an ABS program from a later model vehicle where the firmware is more stable. Ask a Chevy dealership mechanic to see if it can be done.

[Phat]

I know some of what you talk about. Now i dont know if your 94 is anything like my 95 2500 pick-up but in the winter i disconect the 2 front plugs on the system for snow plowing. I have a 93 with no problem but dont have a 94... the 95 and 96 I WILL NOT run with the ABS hooked up in the winter. I have raced oval track cars alot and have gotten used to using my brakes and skidding to get myself out of trouble . I dont need some GM nerd telling me it stops quicker. It may be fine for the average driver that just stands on the pedal...it aint for me. The pedal being low sounds a bit diff...i would have somebody check for bracket deflection and all and all brake problems. One other note the ford system does suck and they deny it. I was a fleet manager in 93 and had 130 something cars and trucks. 11 ford F-250s(89-94s or close too it) with assorted drivers...all but 3 had rearended someone in the rain or snow. They have a big problem and never fixed it......Never bought another till 99. Try removing the 2 front electrical conections and go see if its better in a parking lot... I would also find away to have them taped up as to look as if they are plugged in. Acc investgation teams will catch that one quick if anything were to happen. Good luck

[djracer]

I have a 95 sub and I hated the brakes so I upgraded them. I installed praise dyno rotors pads, rear shoes and springs and stainless braided lines. One word AWESOME! I can literally bounce someones head off the winsheild at will! It makes a world of difference.

Hope this helps

[bwood]

I would agree that the brakes on the Suburbans are undersized. I would start with some slotted front rotors and performance pads. Also try changing brake fluid, I know that this sounds drastic but the fluid can loose viscosity over time. Also check out the brake lines. A set of braided ones would set you back around $80 and while you are putting them one you could swap the fluid. The factory brake lines suck pretty bad. I wouldn't overreact and go removing critical components from the truck. Do you have 4 wheel ABS or Rear Wheel Anti Lock? Some of the older models only had the RAWL system. You might also check the rear shoes and drums. I had a problem with mine, the rear axle seals leaked fluid one the drums and pads. They factory drums were burned in spots and made the truck hard to stop.

[jimfulco]

I think it's just ABS on the rear, but I don't know for sure. It's whatever came standard on 1/2 ton Suburbans. I don't intend to remove critical components, heck the system removes the brakes all by itself in emergency situations already.

[djracer]

I am pretty sure it is 4 wheel abs. Take my suggestion I hated the brakes on my sub before I did the brake upgrades.

[apstguy]

Actually, Subs and Tahoes are a 3 channel system (front wheels indepenedent & rear axle) in the 90's.

[Moloko]

Dont get rid of the ABS, just upgrade the brakes. My Yukon's brakes are spongy too, and since your truck probably weighs so much more I can only imagine how much of a problem you are having. Stainless lines are a big improvement since they dont allow the pressure drop that rubber lines do. Slotted or drilled rotors dont improve breaking, only breaking stability (repeated braking, like on a race track). What you need is more braking surface. Larger rotors, better pads, rear disk brake conversion, etc.

[jimfulco]

Then I'd have a $1000 brake system that would still fail in a hard braking situation.

[Moloko]

ABS does not make a system less effective, it still supplies the same braking force to the wheels. It can react faster than you can, which will lead to shorter stops. They put it on for a reason.

[phantom dually]

My 94 c2500 does not have good breaks unless I warm it up for atleast a minute before leaving. If I dont it will lock up the rears EASY when I apply the brakes. This is more less a vaccuum issue maybe. Also I think the brakes suck also and have had a few close calls. Reduce your driving distance in these trucks!!

[Phat]

If you get the dreaded lock up in the rears chamfer the top and bottom of the brake shoes. It will go away. Honest spent a lot of time on these.(the worst ones are ones in parking garges or near the shore were its damp all the time) As far as "ABS does not make a system less effective" What else would you call a truck that takes almost a full 10 truck lenghts in the snow at low speed to stop?(i own 5 of these so i can tell) Disconnected it will and does stop. Must be something to it as a few techs in the GM dealer ship are also doing it on there personal trucks in the winter. They have a problem as do others. One of the reasons i say give it a try in a parking lot....maybe the average Joe just cant control his own truck and does need it. Its only 2 plugs and hooks right back up. Simply fix if it works for you ....no harm...no foul.

[Mike GeniuS]

Ok, Jimfulco, here it is. I have had the same problem you did. In the driveway, the pedal pumps up hard. Go down the street, and lightly apply brakes, pedal sinks right to floor. So, being an ase certified tech, I first gravity bled, pressure bled, changed master cyl, found a leaking valve on the kelsey hayes unit, so I fixed the leak. Bled the k&h bleeders, everything you could think of. Then I found your post. DON'T LISTEN to these idiots!

This is what I did. I had an old 85 chevy k20 van out back, an old parts van no motor,trans, etc. I'm gonna give it to you step by step. It's exactly what you asked for.

step 1. Don't worry. Disconnect k&h 4wabs & remove entire unit from fender. also remove proportioning valve - it's a four port, & will no longer be needed.

step 2. Go to your loca junkyard, or buy new, a 5 port proportioning valve specifically for either a conversion van or suburban from mid to late 80's

step 3. You should have 1 big brake line on frame coming from rear, there's a brass coupling under the seering column - remove brake line from coupling to k&h. Then there's a smaller line along side the exaust manifold near steering rod. disconnect at that brass coupling. remove that line. finally, on the driver side wheel, where the rubber line connects to metal pipe, remove that steel line,too. you should have 2 brass couplings open & driver side rubber hose open.(where it straps to frame) Now happily toss those three brake lines.

step 4. Mount your new proportioning valve - make sure the 2 small holes are at front & the bigger conn. at the rear. I bolted one hole of the valve to the bottom of the old K&h mount that holds washer bottle. Being on an angle is ok, but make sure it is not higher then the master cyl. now plug in your brake idiot light sw. the tan wire white/black connector. it's exactly the same, & will still function perfect.

Step 5. I re-bent the van rear brake line from the front of the master cyl to proportioning valve & used it to go from back proportioning valve connection to rear bigger brake line under firewall on frame.

step 6. I went to autozone & bought (2) 3/16 (both ends) x 24'' & connect top front small angled-up port on p-valve to driver side rubber line connection. Then connect the smaller brass coupler by exaust manifold to small front angled bottom port on p-valve.

step 7. now there should be 2 open ports left on p-valve. these are 2 ports facing staight up on top. these connect to the master cylinder, just like they did in the van.

step 8. fill master cyl. open one bleeder at a time & gravity bleed. they will leak out fluid & push most air out all by themselves (no pumping.) make sure you leave lid off of master resivoir while doing this. keep filling with fluid(don't let it run dry)

step 9. tighten all bleeders. by now you should have some kinda pedal. now get a buddy & pump - bleed the brakes like normal.

step 10. disconect front wheel abs sensors by disconnecting the 2 connectors by oil pan underneath. no need to remove, just unplug them.

That's it. may sound complicated, but it's really easy. I did it yesterday afternoon after reading your post. IT WORKS FANTASTIC! Totally safe, correct non-abs brakes that will-not fail. The best part, the ABS light even stays out. If you need pics, I can post them.

[Mike GeniuS]

Originally Posted by jimfulco

Chevrolet says there's nothing wrong with the brakes, has said so for years, although many people disagree. I think there were some lawsuits over it, but I don't know how they ended up. My dad & my best friend have both described the same problem, & my friend actually hit someone in the rear because of it. Neither of these two are "white-knuckle" drivers, quite the opposite. If they said the brakes failed, they failed. Both said the brakes worked normally after they let off all the way, it was just too late in my friend's case.

Need Help? read my post ( at bottom of page)

[Mike GeniuS]

My non-ABS conversion cost me less than $20.00 It's the same brake system as a regular conversion van with no ABS. My old ABS would of killed someone it was so bad. just scrap the ABS, replace with a junkyard proportion valve out of a non-ABS k20 chevy van or suburban, couple of new brake lines, & now I feel safe letting the wife & kids drive.