X1. if there was a great enough demand the Chinese would have been in on the case for a while now, but sadly not.

Falcon works seem to have the market cornered on WABCO SVS seals even in europe. WABCO won't sell them even, particularly to us minions who actually own D2's.

 

X2 on the o-rings as our 2003 Discovery had its shuttle valves soaked in fluid. You should also verify you do not have a bad solder joint where the shuttle valve plugs into to the modulator. Test and retest the pins with in the ABS module for weak solder joints. There is a fix on the Hummer website:

Hummer?s Meritor Wabco ABS Modulator - Hummer Knowledge Base PDF Download - arepdf.com

2003 Discovery 144K

 

I believe I have read every page on the ABS repair methods, so I am hoping to summarize my fix here and confirm with people if I am on the right track. As I know it could be wheel hubs, speed sensors, etc. Easy things first.

So, I have a new SVC and the rubber grommets.

My plan is to do the "B" repair, extend the wiring outside of the unit. I expect that I should replace the rubber grommets as well. The instructions with the package from Falcon Works are not particularly clear, but we will cross that bridge later.

Questions:
If I do "B", do I need a new shuttle valve? Can I re-use the old one?
Also, the Falcon Works instructions specify a Super Blue and one other brand of brake fluid as the only acceptable products. What do people think of this? I was planning on using Valvoline as Super Blue requires for thought and planning to purchase in advance of doing this.

Thanks for the feedback.

 

I replaced the shuttle valve without reading the abs codes. I had 'assumed' that was the fault after reading so many cases. Wrong. Mistake. Rookie error.

I now have a nice new shuttle valve, with the option B repair, and the 3A's remain. Awaiting code reader to probably discover a wheel sensor needs doing.

My seals arnt leaking. Shuttle valve was clean and looked great. So I have a spare.

For all those who think the svs repair is a magic bullet for the 3A's, Make sure it's the right kind of Magic first.

 

May be the sensors like you say. I think that's another one of the common fixes.

Did you check your front hubs for play? I think when the hubs get old and have play it will set the 3A's off as well.

I have had several encounters with those...

When I first bought my 03 about 8 years ago it had the 3A's, I cleaned all of my ground connections, on the battery, the connector on the fender, and on the block, and also had to put a new terminal on the ground cable at the battery since it would not tighten like it should. It cured my 3A's for a long time, like years.

then several years later my battery got weak and got the 3A's again and when I put a new battery in they went away again.

another time when they showed up, it was time for new brake pads and rotors up front and after that they went away again for years.

They have only shown up again after I let my truck sit for several months, then after I charged my battery they were gone again for a few weeks, then I swapped out the battery with an almost new one I had in another one and they are gone for now..knock on wood.

So I'm not saying that a new battery or clean cables or any of that will cure your problems, just passing along how it went with me.

These trucks are weird... especially anything to do with electrics.