Help identifying a brake-system part.

[unstable]

Yup thats the prop valve by the looks of it.

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Does your proportiong valve have a black box mounted on the side and a wire coming off of it? It's it electronically controlled proportioning? =)

 

[1997chevydriver]

Yes it does have the box but I believe that box is for abs. That wire on the prop valve I believe is the sensor for detecting low brake pressure.

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[jeff's88silverado]

the black box is for abs the wire on the prop valve is for if you lose pressure on one side of the brake system. It will ground out the wire turning on the brake light letting you know you have a problem.

And as for your problem you can get the prop valve on amazon for $100 ish. And for the RWAL thats underneath the prop valve you can remove it to by running adapter on one line or cutting the line and changing the fitting.

 

[BubbaZ71]

i had to bypass that on my 88 Due to the fact it failed and my pedal was soft.If you remove it your pedal will be right at the top and very responsive.You can bypass it but with the box being unplugged and the unit not in the truck you will get a brake light on on the dash.If you need info on how to do it let me know ill take some pics and type up some info for ya

 

[unstable]

Thanks for the help guys. I just ordered a new one. I'm contemplating just going through the brakes all at once and doing a complete overhaul of the lines because I've replaced sections of lines with flares and unions on other vehicles and inevitably you're looking at blowing out another line in the near future and that gets old and frustrating in short order.

It actually surprises me that stainless lines aren't a standard affair on vehicles. Yeah I know they try to trim costs to maximize their profits...but I've got a 99 Mercury that is headed to the junkyard soon, and before the car was even 10 years old, I had a ton of lines to replace on it and more and more lines kept going. You'd think with something as critical as brakes from a safety perspective that they'd use something a little more long lasting.
/just ranting.

I'm looking forward to getting this thing back together and on the road. I sidelined it because of a few problems with it that I just didn't want to deal with, but with the POS sable hitting the boneyard, it's now time.

 

[MIHELA]

Almost all cars now use nylon armor line. It doesn't rust unless the coating gets damaged. I plan on replacing the rear axle hard lines on my truck and I've bought the line already from GM, 03+ trucks use it and it's the same size as ours.

 

[unstable]

Thanks for the info Mihela. Right now I need to remember how this crap goes back together. Like I said, I'm the shi**est excuse for a shade tree mechanic that the world has ever seen. =(

If anyone would be so kind as to draw me a diagram or snap a couple of pictures of this arrangment, I would be extremely grateful. From the earlier picture I took and trying to use common sense, here's what I've got.

Master cylinder lines criss-cross to the top of the proportioning valve.
Forward line on bottom of proportioning valve goes to truck existing brake plumbing...small line? 3/8's maybe.
Back line on bottom of proportioning valve goes to the abs unit...somewhere.
Only port left on abs unit goes to existing plumbing on truck...this is thicker line.