1990 C1500 ABS (RWAL) removal.

[77Impala]

Disconnect the single wire from the modulator valve and see if the light goes off. This is the valve that tells you by the lamp that one side of the brake system has failed. If it does not then you have a short somewhere to ground. If it goes off and the brakes are working much better than it may be a faulty modulator valve.

 

[deejaaa]

plan on doing this to the 93 3500 when it's back on the road.

 

[Robert Parzych]

I just spent about 40 minutes getting rid of the RWAL on my 90 GMC 1500 Sierra. Had to use the adapter fitting I bought ahead of time. Did not have to bleed the brakes. It has never stopped this good since I got the truck. I think the RWAL valve must be stopped up not letting rears work at all. I did the same delete on my 93 S-10 Blazer. It had 4WAL. Had to make some changes to its plumbing. It stops way better now too.

 

[Sampuppy1]

I really need to do this.

Sent from a flagged XT1254
Tyler/T-Unit

 

[Kamd90Chevy]

ok so i took the pressure switch connector off and fired her up and went for a drive, the light stayed off. i came back, plugged it back in and did the same trip, driving the same way, and the light came on the first time i hit the brakes and stayed on. Is this a sign i need to re-bleed the system and try again or is this a sign that i need to try and find a replacement for the valve?

 

[77Impala]

Try to re-bleed the brakes again. One trick I learned is to have one person press the brake pedal after you open the bleeder and hold it down until you tell them to 'reset', then repeat a few times. Bleed all four wheels. Also bleed where you attached the brake line RWAL to modulator valve. If that does not work then replace the valve itself and repeat the bleeding procedure.

 

[Kamd90Chevy]

sounds like a plan, shes sitting till this weekend when im off Saturday. Gonna go through it all again, plus i need to do the oil change, get the HID's out and back to the regular headlights. and an oil change on the womans daily. ill hop back on if it doesnt work, thanks for the help everyone.

 

[DPotts]

I just removed the Antilock brake components. Brakes are much better. Thanks for the nice pics and detailed instructions. The brakes are better now than they have ever been since I got the truck. It is a 1990 K2500.

 

[Mountianjustice]

I can confirm that this works on a 92 K2500 (4x4) RWAL WITHOUT any sort of adapter, direct fit, though some bending needs done to the rear line to keep it from hitting the inner fender well. Can anyone shed some light on the single wire to the proportioning valve? Is that the brake light sensor?

My 92 C1500 W/T didn't need any additional fittings just removed the little S shaped piece of line and the rear abs valve and connect the single rear line direct to the bottom of the proportioning valve. I spent a good 5-8 minutes trying to get it started. Its a blind spot you just gotta keep trying it will start eventually.

 

[Jordanbert123]

Are these all the sames steps if youd do it to a 98? anything different?