Has anyone done the shuttle valve mod? If so does it work and more important once done will the hill decent, abs and TC work properly or does it just bypass it?

 

Yes I have done it
Yes it works
No impact to hill decent, abs, and TC. It all works properly, it does not bypass the shuttle valve, just gives you a better electrical connection by going around a circuit board that is fragile.

 

Thanks
was it difficult to do or not really
take about an hour?

 

The mod to the SVS is one of the best mods you'll ever do, yes I've done it and yes it works fine. I cheated and purchased a new SVS with the particular mod done slightly differently but basically the same mod and mine has been excellent ever since for a couple of years.

PS: it takes an hour or two to fix and doesn't require re-bleeding the brakes.

 

There are 14 different faults that can trigger the Three Amigos (ABS, traction control and hill descent control lights). It's best to have the codes read to confirm whether or not the Shuttle Valve Failure Electrical Fault is the problem. If that is not the problem Option B will not help. On the other hand, the shuttle valve failure code is very common, and I dare say in many, many cases it's a good bet to do Option B if you don't have access the a diagnostic tool that will read ABS codes or don't want to pay $100 or so to have the codes read. For under $10 in parts and supplies and an hour or so of your time you can give it a shot and have a good chance at success. Just be sure to inspect carefully for any sign of brake fluid having leaked past the seals and into the switches, and check the switches for appropriate resistance, all as detailed in Josh Salas's terrific write-up.

And to your question, Option B does not bypass the ABS system. Option B restores full ABS, TC and HDC function if the problem was the very common defective printed circuit board buried deep within the modulator. All that's being bypassed is the bad circuit board.

 

It works as if you never did anything to the ABS. That is because all you are doing is bypassing a poorly soldered circuit.

 

X1 ............... you have obviously been there also