Okay.. so my Blazer is beginning to make me feel quite like an idiot. I have a print out of the vacuum diagrams posted on the forum, but can not make heads or tails where to begin. I will post the confusing one up, and if anyone could give me some insight I'd appreciate it.

Also, my 4wd works, so I'm am not sure as to how the previous owner has this rigged.. and judging by their wiring skills, I'm honestly a little frightened.

Where is the engine vacuum fitting located? I noticed there is one single vacuum hose running from the intake manifold fitting (where the driver side pcv valve runs to). But the hose runs down behind the dizzy and between the engine and firewall. Can't see where it goes to...

I noticed a lot of old, rotted vacuum hoses just sitting in the engine bay with the connectors still attached, but could not see where they hooked up to. Attachments below.

 

When I redid mine I started with the main line on the drivers side and worked towards the middle and then down and etc. doing a little at a time. And the one hose on the pcv should be the main hose(at least it is on mine :P). Just make sure you get plenty of new hose fittings cause the old ones crack and break easy

 

Oh yeah, I went ahead and bought a whole new box of different fittings lol, those things are hardly ever reusable.

I noticed the brake check valve has an extra fitting on it, that has been capped off, I was wondering if maybe that's what the diagram means as far as the "check valve". Being that the booster would be running off the main vacuum line. I think I'll try it and see what happens. Still no idea where the smaller vacuum hose is running to, but obviously it is suppose to go there from the website I got this image from. Number 3 is what I was talking about. So, I guess tomorrow I will give it a go and see what happens. I've still no idea why my 4wd is working, how they have it run. I guess we will find out, lol.

 

The 4wd should have a vacuum line connected to the actuator or it wouldn't work.

 

I haven't had a chance to check it out yet, but from what the diagram is saying, the vacuum line for the t-case and actuator are intertwined with that of the cruise control and a/c. Neither of which is hooked up, because the check valve is capped off, lol, I know, sounds stupid. Evidently they have the actuator hooked up somewhere.. somehow, because my 4wd completely engages and disengages. I probably won't get a chance to look at it until Friday, if not before work the next two days, but we'll see what we've got.

 

And for number 3 and 4 on that photo number 4 should go into the canister in the driver side fender. It's a pain in the *** to get the hose on that fitting because of its location but if you feel for that little vacuum fitting Thats the best I could get to give you an idea :P

 

what is number 3 called? Was changing spider injectors on friends truck and can’t find what happened to this part and can’t find any reference on the actual name besides an eBay seller so I can get one. I’m attaching photo.

 

brake booster vacuum cover, its the same part on 98+/MPFI trucks or those without hydroboost systems.

 

when I look up this part it shows ones that don’t have the section that plugs into the cover. I understand these are aftermarket but I don’t want to chase parts down that won’t work. Any ideas?

 

Does anyone know if this is the Vacuum line that goes through the firewall to the HVAC?