I have Warn hubs that I have to lock in. All works good. A/C goes to defrost at first when cranking but then runs fine after a couple seconds. So, I was thinking that maybe my pump is running all the time. Who knows. I'm sure all my vacuum lines are dry rotted. What exactly is the need for it exactly and what's the best way to cap? Hoping to do it at the unit itself if possible.

Thanks Jed

 

The going to defrost seems to be normal (only at start up), at least that's how mine works too, but the pump should kick off after about 30 seconds or so. As for capping the lines going to the hubs, I just pulled them off, and capped them with some rubber caps I got from the auto parts store that slip over the end, held these in place with silicone. They rubber line just goes between the fender well and the knuckle. Make sure you cap off both sides (fender and the knuckle) to prevent water intrusion into your knuckle....

After you have capped these lines see if your pump does indeed turn off after a half minute or so

 

sounds as if your vac lines have a crack and are letting air into the system, the pump should only run long enough to pull about (estimated) 1Hg or so of vac, that is why you have a vac tank (the big black tub thing) which should hold at least a few changes of the vents, and/or esof system before the pump has to kick on again to "recharge" the vac canister...

if your wanting to just cap the vac pump get the small caps (i forget the part number) to cap its vac ports, I DO NOT have 4x4 so I can't comment on this part, as for the vents, you will loose functionality of your vents, and get defrost only, if your good with that then continue on...your ESOF lines are known to crack at or near the front hubs where the vac line connects to them, replace it even if it looks good...


EDIT: looks like Rickster posted at the same time I was...

 

The last time I checked mine it ran about 30 seconds like Jaimie and Rikster. Then it took about 35 minutes before it started again. When I cut my ESOF solenoid out of the picture I ran the line out of the tank directly to the HVAC system, no capping anything. Pump to tank and tank to HVAC, very easy to do.

 

I pulled the vacuum T off the reservoir and capped it off (blue cap in pic) disconnected HVAC vacuum line (white cap w/zip tie center right in pic) then ran the HVAC line straight along fender to reservoir. Cuts the ESOF out of the equation but it's reversible if you want to go back to stock.

 

Here's the tubing I ordered to replace my vacuum lines. About $7 for 10ft.

Blue 5/32" 4mm Vacuum Silicone Hose Turbo Intercooler Coupler Pipe Turbo-10 feet

I haven't done it yet, just rebuilt the drivers front wheel with new wheel hub, top and bottom ball joints, rotor and hub.

I recommend servicing the ESOF hub and replacing the outer oring. Here is a link to my thread, with a link to Diesel Oring's site for the snap ring and oring.

www.ford-trucks.com/forums/1452477-esof-hub-clicking-how-to-repair-rebuild.html

It has lots of pics of the ESOF hub internals. I also replaced the internal bearings and lubed it all up.

If you have a parts washer, it really helps

 

I'm stealing this pic!

It will save loads of time when I replace the lines. Should certainly help the OP troubleshoot his vacuum pump, too.