2001 ZR2 Vacuum Solenoid
 

New guy. I know its been talked about 500 times, but I can't find this specifically. 2001 ZR2 that I'm fixing up. I've got a 4x4 issue that I am almost sure is vacuum related. HVAC got all freaky at the same time. I'm going to fix it this weekend, but one thing I've noticed is that I don't have a solenoid on the firewall near the distributer. Or, if I do its hiding.

My question is on an 01 ZR2 do they have one up there? 3 button 4WD.

I've replaced the dizzy and didn't see it, and I've looked around that area and didn't see anything that looks like the thing and I've had a few of these trucks before.

I am just trying to get a handle on this specific truck so I can tackle it. I'm worried somebody may have bubba'd it, but the rest of it looks pretty clean. Ican actually hear it leaking from behind the HVAC panel, but when I checked the lines to the canister in the fender and under the truck they were brittle like the rest of them. So, I'm going to swap everything.

No solenoid with the 3-button. You have a switch on top pf the transfer case.

Copy thanks. Is that switch vacuum operated and/or prone to failure. I'm about certain its a vacuum issue. I guess my question is there a diaphram and vacuum down there?
rj

Take a look here...this is the extent of my knowledge about the vacuum system. If you have hissing, it's probably coming from behind the HVAC selector knob. That's where all the HVAC vacuum lines meet up behind the dash. Also, be sure to check for fluid in the vacuum lines. If there's any moisture in the lines, it's coming from the transfer case, via the vacuum switch.

The lines do have some fluid, albeit just a little. I was able to pull the ashtray out and saw some there. Hoping the tranny seal isn't bad, but it is what it is.

fix the trans seal before you worry about the vacuum lines... or you'll have to do the lines again...

If there is fluid present does it guarantee the trans seal is bad? Its very slight, almost like condensated vapor.

Is it the outputshaft seal? Any links to the fix?

Have not got under the truck to check the transfer case fluid level. My plan was if that was normal, just change the switch and the lines, if not pull the tranny and replace the seal.

When you pull off the t-case fill bolt, you'll know if your seal is bad. I just don't think there's any other way for ATF to get in the lines, other than having an over-full t-case and the fluid pushes its way past the seals in the vacuum switch. The only times I've ever had hissing behind the dash, it's been because of ATF in the lines.

Thanks, you all have been a great help. When I got the truck the oil was over serviced so it would not surprise me if the T-case was done as well. But, its hard to overfill as it would just run out the fill hole. We are talking about me, so no doubt the T-case seal is bad. Murphy and I are old drinkin buddies ;)

I'm in the military and work in DC during the week and go home on weekends. So I've got to do as much as I can in a short time. I picked up the vacuum switch so I've got that. Trying to see if that T-case seal is doable. Can't find the procedure here yet. My service programs are at home.

LOL! So of course I pull the fill plug and about 2 quarts pour out. I love my life. In the process of trying to figure out how to drop the transfer case. Got both driveshafts out. Took tranny mount out and I can see the bolts with it tilted down. But it don't look like there is enough room to pull the case off the trans before it hits that welded in crossmember?