ABS brake parts on a 98 C20, any way to eliminate all that stuff, for plain brakes???

[68Gold/white]

It's a 98 3/4 2WD LWB. Has the 350 vortec with the HD trans. The brakes have always been a pain. This is a good friends pickup. I have replaced the vacuum booster, and the m/cyl. THe booster has gone bad again.

I'd like to pull ALL the abs garbage off and just run plain old hydraulic brakes.

Anyone do this??? I have looked and can't see a proportioning valve???

[Palf70Step]

The square ABS block acts as the proportioning valve. I believe 92 was the first year of ABS brakes (rear only if I remember correctly). I wonder if you could find what you need in an 88-90 model. Then you'd have factor available parts to get around it.

Not sure on this, but just something I thought about when I had my 94 and was wanting to get around a leaky ABS block.

[special-K]

I run a '95 Suburban K2500 with just straight brakes using all the original parts. I am experienced at working on older stuff. This was a first front brake job with ABS for me. All I did was get some anti-seize on a sensor and now I don't have anti-lock brakes!

[speedygonzales]

All you have to do is get some hard lines and go around the ABS unit. In other words, connect the master cylinder directly to the lines running to the brakes and bypass the ABS unit.

Remember that when you do this, the ABS inop light will illuminate in the dash unless you have the light programmed out.

Incidentally, I am convinced the ABS unit is what makes the GMT400 have such poor brakes. I believe removing the ABS unit in this way will give these vehicles the proper brakes it should have.

I say this because my sons 84 square body has the same MC our GMT400's came with and his will put you through the windshield. Ours, not so much. The only difference is the ABS unit on ours. So I am convinced the ABS is a restriction that causes us to have to press the brake pedal much harder than any others.

I was going to give it a try some day just to prove my point.

[Palf70Step]

That is why I suggested using the 88-91 models for the proportion valve and prebent lines. On my 94, if I disconnected the lead from the ABS module, the light goes away, basically never comes on for that.

[KQQL IT]

I put a 3500 dually rear wheel cylinder in my 2500 and made a big improvement in my pedal and feel.

Disclaimer: also did rotors ceramic pads braided hoses and the wheel cylinders at the same time.

[68Gold/white]

Originally Posted by Palf70Step

The square ABS block acts as the proportioning valve. I believe 92 was the first year of ABS brakes (rear only if I remember correctly). I wonder if you could find what you need in an 88-90 model. Then you'd have factor available parts to get around it.

Not sure on this, but just something I thought about when I had my 94 and was wanting to get around a leaky ABS block.

I was wondering about the lack of a prop valve.

It's not my vehicle, or I'd try bypassing the box.

I put a new vac booster on it, over weekend, 2nd one in about 3 years. My buddy doesn't drive it much. I drove it the other day, TOLD HIM, screw this no stopp'n beast I' M going to fix it this weekend. Booster is not an easy deal, not impossible. THe booster WAS bad. Not sure where we got the last one, going to check on warranty...I think it developed a small vac leak not long after I installed it...

[gmc684x4]

You could look at puting a hydroboost in it

[Tom]

I've had one vaccum booster go bad in 15yrs and 120k miles of driving my 98, and that was around 160k miles on the clock.

Put a gmt800 master on it and enjoy better pedal feel.

I've done 3/4ton calipers and pads, steel braided lines, rear NBS disk conversion with 2 piston calipers from a tahoe, the abs bleed threw the OBD connector, and the NBS master cylinder. The master made the biggest difference in pedal feel, by far. I don't see any reason what so ever to remove the ABS at this point, everything works and feels great.

[68Gold/white]

I installed the new vacuum booster, that fixed the falling pedal part. I was talking to my buddy, the owner yesterday. He told me it seems that the ABS system seems very sensitive. The least little bump in the road or a rough patch in the road, makes the brakes go into the anti lock mode, usually when you least expect it. He knows what to do, driving wise, when it happens, he just can't let anyone else drive it, especially his wife..

I plan to do some experimenting here sometime. Will report back

[Tom]

That was a big issue in the 99+ trucks for a while I've read about. Never heard it being a 98 or later problem.