I had another thread about my hub and brake problems. Also figured out my vacuum solenoid was leaking, giving my 4wd and heater fits.
I hooked up a Mityvac and started messing with it just to see what I could do. First, took the top cover off and everything in there looked fine. Then tapped it on all sides with a hammer to see if something was stuck. It went from holding no vacuum at all to holding some. Still lost about 1" of vacuum a minute but progress. Something was stuck why not try make it not stick again or at all?
Got out the silicone spray and squirted some into the top vacuum connection and hooked the MV to the bottom port to pull a vacuum. Then cycle the 4wd switch to try to pull a little silicone into the solenoid(s). After the 1st time it still leaked a bit, but didn't seem to be as much. So I sprayed and cycled it again.
After the 2nd time I pulled 15 inches of vacuum on the bottom port and it held steady for about 20 minutes. So was it the silicone or the cycling that free'd it up? I don't know but it's back in the truck and working for now. I'll keep tabs on how long the vacuum pump runs once in a while. Just in case it sticks open and screws up the heat again, I'm keeping a plug handy for the red vacuum source tube...and money in the bank for a new solenoid.
Throwing it out there for others who have what looks like a good part and want to tinker with it.
I hooked up a Mityvac and started messing with it just to see what I could do. First, took the top cover off and everything in there looked fine. Then tapped it on all sides with a hammer to see if something was stuck. It went from holding no vacuum at all to holding some. Still lost about 1" of vacuum a minute but progress. Something was stuck why not try make it not stick again or at all?
Got out the silicone spray and squirted some into the top vacuum connection and hooked the MV to the bottom port to pull a vacuum. Then cycle the 4wd switch to try to pull a little silicone into the solenoid(s). After the 1st time it still leaked a bit, but didn't seem to be as much. So I sprayed and cycled it again.
After the 2nd time I pulled 15 inches of vacuum on the bottom port and it held steady for about 20 minutes. So was it the silicone or the cycling that free'd it up? I don't know but it's back in the truck and working for now. I'll keep tabs on how long the vacuum pump runs once in a while. Just in case it sticks open and screws up the heat again, I'm keeping a plug handy for the red vacuum source tube...and money in the bank for a new solenoid.
Throwing it out there for others who have what looks like a good part and want to tinker with it.