Blue2016XL

Oh the other thing I learned, at least for 2010 and can only assume it is true for newer trucks, is that the climate control is also vacuum controlled. Were you doing anything with the climate control when it happens? It could elude to something going on there. For me, I wasn't touching anything in that regard and the SM said to replace the solenoid based on my description of the symptoms.

johnday in BFE

iTrader: (1)

LOL, that worked for you!
I think I'll look at the valve tomorrow, don't have any thing to pull a vac with, but I can at least see if there is any place where I might find a leak. Maybe the valve/solenoid just needs a little persuading.

Blue2016XL

I did the same thing. I even traced the hoses back from the IWEs to the valve and solenoid. I just kept coming back to the conclusion that if I had a leak, it wouldn't come and go. SM agreed with me and said it could be (in order of what he thought it would be):

1. Solenoid.
2. Climate control (if it happened while it was being adjusted).
3. Or engine wasn't producing enough vacuum.

Didn't think it was either of the IWEs due to it coming and going. When he pulled the hose off of the check valve on the new truck, it was obvious that the new truck and more vacuum applied to the lines than mine. Mine had vacuum but, clearly not as much. Since it has been almost a month since replacing them, I have not had a reoccurrence. If I had a small leak, I think it would have shown up by now.

Good luck in you quest. I'm tired but, if I remember other little tidbits of what I learned I'll post them.

jjc155

lmao

j-

jjc155

There was one thread that I read on the Solenoid that said where it was mounted that water would leak on it when it rained or when you washed your truck and that that could be part of the issue or cause of a failed/failing solenoid.

J-

johnday in BFE

iTrader: (1)

I'll get out there and try bypassing the solenoid just to see if the problem quits. Couldn't hurt anything just driving it like that. It's 35 miles to the dealer and might save the IWE.

I'd still like to know about the vac pump though. Does the vac system rely solely on the pump, or is engine vac the primary source until it goes into boost?

Blue2016XL

I think that was one the 2009 or 2008 and earlier. Mine is on the drivers side off of the brake booster. Hopefully they left it there or off of the firewall for his year of truck.


I hope you mean where you bypass the solenoid but, still have vacuum applied. If not, your front wheels will be locked together like they would be with the truck in 4WD. Not sure how far on dry pavement they would consider to be to far.

I'm sure I don't need to tell you this but, going to say it just so you don't forget. Be sure to plug the hose that supplies vacuum to the solenoid.

Sorry, can't answer your other question.

johnday in BFE

iTrader: (1)

Definetley plug those lines!!!
AFAIK, mine is on the left side up by the brake booster like you say. I'm going to just disconnect the vac supply, and route it into the IWE lines to maintain the vac.
My last Superdude, I was a total jack*****, and lent it to a scumbag that drove it all day with the hubs locked and Tcase in 4 hi. He managed to do a lot of damage to the Tcase, hubs. Never even offered to pay for it. Needless to say, I prefer not to be even be in the same county as that white trash POS.

johnday in BFE

iTrader: (1)

Well, doesn't appear to be the solenoid/valve. I bypassed it, took off, and it seemed worse. Have a 1000 tomorrow at the dealer, looks like it's hub time at 623 miles.

Blue2016XL

Ouch! Sorry to hear about that. At least it'll be covered under warranty. It still may not be the hub though. Could be a vacuum issue though. Plugged or partially plugged line somewhere.