1990 C1500 ABS (RWAL) removal.

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bobby v

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Ok so I got to doing this today and all was going swell till I tried to break loose the fittings on the dump valve, after almost 30 years of being together they didn't want to come apart, in fact they didn't even after soaking them with Screw loose, all three kinked the brake line and finally came out looking like a pigs tail, even the one line that was going back to the proportioning valve :bawl:
So I had to try to disconnect that at the union at the bottom of the firewall and with headers it was a, excuse my French, a mother *****!!! Stuck like hell and no room to work period!!!! I soaked it with loosen juice and let it sit awhile, no dice, so I got my little butane torch out and heated it some. After cussing every word known to man it finally broke loose, Yippee. So off to the parts store for a brake line and Ill try to finish 2morrow after I attempt to bend the new one to fit, then I guess Ill have to bleed the rears for sure now. I hope it all works after this fiasco
Wish me luck
Bobby V
So had trouble with the lower brass union leaking damnit, but I turned the line end for end and it stopped, bled rears and all seems natural, good pedal. The ABS light came on for awhile but just went for a test run and its out now ???
So inspite of having some problems its all good :grd:
 
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bobby v

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After not thinking the job helped out with the pedal feel that much I decided to bleed the rears again today, got a lot of air out. So my test drive went great and the pedal definitely is much improved, I would do it again
Bobby V
 

mars2878

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After not thinking the job helped out with the pedal feel that much I decided to bleed the rears again today, got a lot of air out. So my test drive went great and the pedal definitely is much improved, I would do it again
Bobby V


glad it worked out for you
 

gordonm1

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So I finally did my 1991 WT and with engine off pedal stays high as about any brakes I've had but there is still alot of travel running down the road (more bleeding?). I think it has in part to do with rear drum adjustment and the 1/2 ton size master cylinder has to travel farther to pump the same fluid volume. Front brakes seem to grab better now and I am glad I did this but the real test will be with a full load in the truck. I did not need any adapter for the line but have some open ends on the wiring still to clean up.

I had recently been through the brakes and was not happy yet. Going from 9" 1/2 ton to a 10" 3/4 ton booster helped a little. Just need the final testing and maybe rubber lines I have waiting.
 

bobby v

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After not thinking the job helped out with the pedal feel that much I decided to bleed the rears again today, got a lot of air out. So my test drive went great and the pedal definitely is much improved, I would do it again
Bobby V


Wouldn't you know it, I have the Little Shop rear disc conversion going on this week and they recommend re-installing the proportioning/dump valve to original lol, plus a new MC
Hope it works good
Bobby
 
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I can't speak for the 94+ but on the 88-94 it gets rid of the brake light


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I did this on my 90 model Sierra and now it has rear brakes. I almost rear ended somebody who didn`t signal for a right turn. My truck had no rear brakes because of the failed cast iron valve below the master cylinder. Now has great stopping power.
 

Kkortman112

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Just wanted to add another satisfied customer. I just did this last week and brakes are a lot better. 1993 C1500 Silverado with a 4.3 and didn't need the adapter. Looking up my brake issues is how I stumbled across this site.
 

CADET115

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Ok I'm new to the forum so please tell me if this is not the correct place to put this. I just noticed this is literally what I need to get my truck road worthy. It's a 1991 C/K1500 Scottsdale 5.7 V8 Manual. Reading through I have found the Isolation dump valve isn't the one in the picture and I want to make sure that the thing I'm even staring at is the isolation dump valve. (I would post a picture but not quite sure how to do that on this forum) Any help is appreciated
 

lokitruck

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Im getting ready to do this tomorrow and my dump valve doesnt look like the one in the pics on page 1. Is this going to be an issue?
You must be registered for see images attach
 
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