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From: BC Canada
There is also a connection to the 4*4 locking hubs, down behind and below the battery there is a tube coming up from the pass side axle. This would mean if it's disconnected that when you activate 4 wheel drive, all the vacuum will be lost and then the heating and cooling will default to defrost and stay there.
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More Turbo
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I guess it seems not to be going it to 4x4. When I unplug that line the vacuum pump doesn't kick on, but the other line going toward the firewall up high does kick on the vacuum if I unplug it. Where do I get new lines? Confused that it doesn't try to pull vacuum when I separate the line though?
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Joined: Jan 2005
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From: BC Canada
Where is a control valve that uses vacuum to activate the hubs. It's bolted to the fender. It only uses vacuum from the tank when you switch 4*4. If you take the vacuum pump line off that goes to the tank and plug it with finger, the pump should **** off. Then plug into the line to the tank and check the lines hold vacuum. The see if the hubs hold vacuum. I have had to replace the line that goes from pump to tank and over to the hub valve and the HVAC on the firewall. I have also had the line at each wheel to the hub go and had to replace. The rubber lines go pinky and don't hold a vacuum, they need to be replaced. I have also had to replace the 4*4 solenoid, that actives the hubs vacuum line, it's gone bad on me twice. So, you have some trouble shooting to do. One step at a time and you will get it. Just takes a bit of patience.
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