'95+ ABS Removal Questions

[df2x4]

To start with this thread is purely for research purposes as I don't intend on removing ABS on either of my trucks at this moment, or possibly ever. I've just been digging through some older threads and trying to learn more about removing the Kelsey Hayes 4 wheel ABS system from '95+ GMT400s. I found this very informative post from DRAGGIN95 in another thread:

I have done this several times, on 88-94 2wd truck like mentioned you remove the ABS control module and rear abs valve, be sure to keep the proportioning valve though you need it to keep proper brake bias from the front and rear brakes. Anyway run a new piece of line from the rear brake line junction on the frame just below the firewall to the proportioning valve and that's it. For 95+ originally there are 2 independant lines running to each front brake caliper that run directly to the ABS unit, there are 2 way's to deal with this, either unhook the both front lines at the abs unit and install a tee, or what I do is go the salvage yard and buy the front brake lines and proportioning valve off of a 88-94 the front lines on a 88-94 tee together originally so with this method there are no other tee's needed, I can get it all locally for $10. The rear on the 95+ still only uses 1 brake line that runs directly to the abs unit, it can be unhooked and hand rebent to hook up to the 88-94 proportioning valve, or you can just buy a new piece and run it from the junction on the frame under the firewall to the prop. valve. It's not difficult to do at all. Also one interesting note when the power and other plug's are unhooked from the abs unit on the 95+ the abs in dash light does not come on, even though you would think it should.

So basically it looks like you need a combination/proportioning valve and some new lines. Here's where my questions begin. So instead of a junkyard '88-'94 proportioning valve and front lines, let's say you wanted to use an aftermarket adjustable combination/proportioning valve. Would something like this Wilwood unit be appropriate? If so are the fittings the correct size? (Looks like the Wilwood has 3/8"-24 inverted flare)

https://www.wilwood.com/MasterCylinders/MasterCylinderProd?itemno=260-11179

Also I've seen others mention using a residual pressure valve on the rear line for the drums, Wilwood has a 10lb one that they recommend for this purpose. Is this necessary?

https://www.wilwood.com/MasterCylinders/MasterCylinderProd?itemno=260-13707

Any info is appreciated, my knowledge of this stuff is very limited.

 

[letitsnow]

I have used that wilwood proportioning on both of my trucks. One is a '98 s10 which already had rear disc brakes, the other a '99 k2500 that I converted to rear discs. I also removed all lines and ran new 3/16" hard lines + all new rubber lines.

The s10 obviously was designed for 4 wheel disc, and the brake pedal height and feel are real nice. The k2500 was designed for rear drums, and the pedal travel is more than I would like, but the brakes work very well once the travel is taken up.

Neither job was straight forward - both required custom stuff and patience.

 

[Pinger]

Also I've seen others mention using a residual pressure valve on the rear line for the drums, Wilwood has a 10lb one that they recommend for this purpose. Is this necessary?

All I know about the residual valve is what I've read on this forum and that is that by maintaining pressure in the rear cylinders it keeps the seal lips in contact with the bore and thus prevents air being drawn in on retraction of the pistons (when the seals would otherwise 'relax' their contact).

Strikes me that that would be more beneficial when the pistons were moving over a large stroke and wouldn't that imply that the brakes were in need of adjustment? Or is the adjustment at the opposite end of the shoes?