Does anyone know where I can get the solenoid. 7C3Z-9H465-A Also it seems that my pump is always running. I checked the lines and don't see or feel any leaks is it okay that it seems to run all the time.

 

Welcome to FTE,as far as where to get the solinoid,im not sure,but as far as the pump always running check the lines going from the pump(on the pass.side fender well) down to the hubs,or it could be the yellow o-rings in the hubs themselves.Someone else will be on shortly with more info.

 

He will take good care of you. And welcome to FTE.

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Well I replaced the solenoid and the heater runs normal until I put it into 4 wheel drive, then it defaults back to defrost and no 4x4.

 

you may have a cut line going to your vacuum hubs. I already replaced everything on mine. The vacuum pump goes to the shift solenoid, which is activated by the 4wd selector. From there the lines go under the motor to each hub. Chances are if the vacuum lines are good, the vac seals at the hubs are bad. Check the hoses from the frame mount to the knuckle.

A cheap and fast fix is to pinch off or plug the vacuum line by the selector valve and manually operate the hubs.

 

I am watching this one too, and have some confusion about troubleshooting the vacuum pump/solenoid.
My hubs do not engage when I switch at the dash. They were rebuilt after a front axle kaboom a couple years ago, and I work them every month. My HVAC controls work fine when not in 2WD, but upon going to 4WD on the dash it reverts to defrost. How does the solenoid affect that when operating in 2WD so long? Does that open another vacuum system, which then leaks so much that the controls revert?
When in 2WD and starting from scratch, all would be cool until the solenoid operates?

I have replaced the lines from the knuckles to the frame by the brake, and can feel vacuum there with each finger. The nipples were actually so corroded I am replacing them, but they had a very small orfice on the thread end. I assume that is just to keep it cleaner inside? Can a typical brass nipple work?

My pump will run when the ignition is on, but after I try to switch it over to 4WD, it will run a long time, I finally quit after 4-5 minutes. About to buy a vacuum gauge and start testing, but for what I can search, it seems to point to the solenoid.

I hope that didnt confuse y'all, but thanks for any info.
Dig

 

fordff,

you have an open line somewhere in your system after the selector solenoid. All the solenoid does is allow vacuum to go to the hubs. When you activate the solenoid, it just opens a valve and allows vacuum from the accumulator tank to the hubs. Nothing magic or complicated. If you loose your heater controls, its because they are vacuum operated and you are loosing vacuum because of a hole somewhere between the solenoid and the hubs.

My fittings at the hubs did not have an orifice, it was just full of rust and crap. Most likely cause is bad/worn vac seals behind the wheel bearing. Not all shops install these right. Ford has a special seal took for this and a guy needs to know what he is doing when these are put in. I have done a dozen or so and own all the special tools for this type of work. Then you need to install a new oring around the wheel bearing/hub assembly (remember to clean the groove). Ford also recommends installing new orings at the locking hub. If your appear to be good, nice and round, I would re-use them. If you question them at all, new ones are cheap, only a few bucks for them at the dealer.

 

Ah, I get it. I am guessing all the junk in the nipples has found its way down into the hub. Hoping for a quick and easy no brainer. Ford dealer put the hubs together, and worked well ever since, (well, before this, anyway)

Will pull em before the snow flies too bad. Thanks for the help.