Remove ABS '90 Suburban

[TommyM]

I searched, but didn't find anything that really answered my question.

I want to remove & discard the rear antilocks on my '90 V2500 Burb. The PCM and engine harness are actually from a '91 V2500, if it matters.

This is the rear-wheel antilock unit that is mounted on / under the master cylinder.

Does the ECM/PCM care if the ABS is present?

Can I just remove the hardware, and pull all the wiring out of the harness?

Anything to beware of (besides locking up the brakes. . .)?

Thanks,

Tommy

 

[plumber mike]

Subscribed. It on my list of to do's but haven't done the research yet(wire tracing)

 

[gone huntin]

Mine on my '90 Suburban went bad and the brake light on the dash was on all of the time. I just dis-connected the harness from the controller and had no more abs or light on. I didn't affect anything else.

 

[dremu]

Back when I had a '90 Burb, I just disabled the damn thing by unplugging the ABS computer at the master.

If you wanted to be permanent, you could unplumb around it, sure, and unwire. The rest of the electronics don't care.

-- A

 

[desertrat67]

Yup, my computer is burried somewhere in the shop. No ABS or lights.

 

[dleroy43]

I cut the wires out at the harness, used the 12v for o2 sensor. Then where the module was at, I installed an adjustable prop valve

 

[TommyM]

I just thought I'd follow up since I asked the question in the first place. After reading over the wiring diagrams and seeing that the ABS really doesn't provide any ECM feedback, I unplugged the ABS computer and all is fine.

Literally just a few minutes after I disconnected it, I was hauling about 6300 lbs of water on my 1200 lb flatbed trailer at about 30 mph when I suddenly found myself in the middle of a whitetail deer parade running perpendicular to the hard-packed dirt road. I nailed the brakes, and left a nice set of black stripes on the road. Somehow I managed not to hit any of them, but I imagine they were telling that story around the campfire later that evening!

When I unplugged the ABS, I started following the wires back through the harness and decided I didn't want to untangle that mess right now, so I just tucked it up in there and tied it down to deal with another time. I wish I'd thought of this a few weeks ago when I had the entire harness out laying on the workbench!

I've decided to go hydroboost with the brakes, so I'll probably just leave the abs dump valve in place until I get around to that.

Tommy

 

[dhcomp]

If you disconnect the box, do you lose all functionality of the brake warning light? Like, if you positioning valve clicks one way or whatever (sensing fluid loss on 1/2 of the system), will the light still work? Does it still work for the e brake?

 

[TommyM]

Yes, those things still work the old fashioned way, they just share the light bulb with the ABS.

 

[dhcomp]

So both large connectors to that black box on the mastercyliner mount are just the abs? Damn. I've never even felt the abs work on this truck......

 

[TommyM]

If I understand the system right (and I don't care very much, hence getting rid of it), it doesn't do that bouncy-pedal thing like most ABS. It just dumps fluid from the rear circuit to reduce pressure under really hard stops. So you wouldn't necessarily feel it.

 

[dhcomp]

Got it. I'd rather it be gone too. I disabled the one in my 94, and had to brake-at-the-limit in a few panic situations, never had a problem. My trained foot is all the abs i need.

 

[badmix]

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