Quick question guys.

I'm gonna do the option B repair. I ordered the trailer harness for the SVS repair, should be here by Tuesday. My question is, can I start the repair (remove the SVS) and still drive the truck while waiting for the trailer harness to arrive? I have time today to start the repair, but need the truck to be driveable.

Thanks!

 

Don't start it until you have the wires, job doesn't take long at all. 2 foot long wires and 2 wire taps are all that is needed. The instructions make more work than needed, in my opinion. The shuttle valves connect to ground and to the wire going to the ecm. The ground wire and the ecm wire both come out of the abs unit and it does not matter which wire you hook up to which. Cutting the wire from the loom to attach one wire, and finding a ground for the other wire is not needed. They make very good wire taps that you can just tap into the existing wires and be done with it.

 

I had problems finding wire taps. I went to O'Reilly and all they had were the in-line clip on type taps. I would suggest look for those while waiting. The smaller screw on type taps. Otherwise a cut and splice will work.

 

I suppose you could, but as Joemamma implied you wouldn't gain all that much by doing so. I wouldn't bother.

 

If you have some time, have you made the allen-wrench socket tool yet? If you plan to go in with just an Allen key, it will likely be frustrating. Also, do you have a small, flat, compact mirror? I lifted the SLABS up, placed a block of wood under a corner, laid the mirror flat underneath, and used the socket with allen key cut inside. The mirror helps to see the 3 bolts and that socket is a must have. Otherwise you'll make hundreds of tiny turns, if you can get the leverage you need with such a short key wrench.

I suggest cutting a length of about 3/4-inch of allen key. I cut mine too short and kept having to lift it up and hold it in the bolt. If it is longer, the socket will rest on the chassis and push up on the bolt, keeping it inside the hole. Much easier if longer than shorter.

 

Check out this video from AB on fixing the 3 Amigos:

How To Replace Shuttle Valve And Hydraulic Control Assembly On Discovery Series II

The mechanic in the video basically just manhandles the SLABS, turning it upside down to get to the allen bolts underneath. No special allen wrench needed if you follow his instructions.

Check it out!

 

That's a perfect write up of the fiddliest part of the job. Yes, totally need a small socket wrench and some kind of Allen bit in there.

Lifting the unit far enough up puts a bit of strain on the brake lines, but I've not heard of anyone having problems with them. I used a couple of blocks of wood, to get the right height.

Those little Allen bolts are tighter than you might expect, adding to the slight frustration. Once you get a handle on it though it's not bad.

 

Yes, but that requires a brake bleed if you disconnect the lines. I agree - much simpler if you don't mind bleeding brakes after.

 

I had these and they are, in my opinion, the best for this application. I admit kind of pricey, but the whole mod is inexpensive. I got these on Amazon for another project and had several spare ones in tool box.

 

I agree, I just lifted it up and put small 2x4 block to keep i up. I just used regular allen wrench and they came right off(with a little pressure mind you).
I did not want to bleed anything and do anything to make more work for me.
Although, I have been doing this kind of thing for 40 some odd years.(Man I feel old, sometime)