where does the vacuum line go from the vacuum actuator ? 99 s10 blazer ls 3 button 4x4

 

It should go up to a check valve somewhere on the firewall area. There should also be two other lines coming from that check valve, one going down to the transfer case, and the other should be coming from the intake manifold

 

It runs from the actuator down to the vacuum switch on the transfer case.

 

ok all the hoses coming off the transfer case are there but i followed them up but it seems like they all go up to the intake?

 

I know two of the lines from the transfer case go up to the engine compartment, does it matter which one goes to the front actuator? I think my problem is there, because my line from the actuator goes to a check valve over by the brake booster. I looked for the diagrams and cant find them, there are thousands of posts on the site and none of them clearly lay out the 4X4 system vac diagram, at least that I can find.

Thanks again for your help!

 

Well... "NV233+vacuum+diagram" turns up:
2 Gen 4wd Diagram
AND this:
95 blazer s10 vacumn diagram

 

Thanks, obviously mine is routed wrong. So I am going to use this and re-do all of my vac. lines and then replace that actuator. I can see one line coming up the back side of the engine, but not two so ill have to figure out where the other line is going and connect it to the actuator. I bought some line and T's today so maybe this will get it working for good. Thank you so much for you help. I will let you know when it is fixed.

Jeff

 

Ok good news is, I found the missing line... it was down in the right side of the engine laying on the frame, the line going across the motor from the actuator must have been installed by someone who didnt have a clue what they were doing. I corrected the vac line routing, re-installed the resevoir and another new actuator, and guess what...... 4WD works and so does the HVAC controls....

All I can say is THANK YOU, your help has been immensely valuable. I am a poor college student with three kids and a wife to support and honestly I cant afford to have someone else work on my vehicle, so this forum was a HUGE benefit for me. I cant say thank you enough for the time you took to help me out.

 

Ok so i replaced all the vacuum lines and checked the diagram on here it's right, has good actuator, new encoder motor, and and front diff engages, but its still stuck in 4hi, my new ? is the vacuum switch,can that be the problem it seems like the vac to the actuator is on all the time and when i was going down the road today it was going in to 2wd and blinking and then back to 4hi



99 ls 3 button 2wd 4h1 4lo

 

The vacuum system only engages/disengages the front axle. It does not have anything to do with what mode/range the transfer case is in. If you are stuck in 4HI, then there is a problem with the TCCM and/or encoder motor.