When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I googled the question several different ways and read what came up. Most of what was useful was from this forum. But, like most forums, the search function on here sucks so bad you are better off to use google. It took awhile. Most of the information is on the 3 button 4wd.
mike5511, thanks for posting the diagram. It should be helpful to people. I might even go back to the start of the thread and put the extra bits I missed like the diagram in that first post so that it is all easier to find.
As for diagrams for specific vehicles, if I remember correctly, even with the GM manuals it is not easy to find them as they the HVAC, Engine and 4wd systems are treated separately and you have to piece together a composite diagram.
For those of you interested in the lengths and sizes for the vacuum hoses that control your transfer case and HVAC that live under the hood of your rigs, here is the list of the sizes and length of each I used on my '99 Blazer LT with 4WD (4-button 4wd/Auto-4wd/NVG236 transfere case)
Intake supply line:..................7/32" ID, 7/16" OD, L = 20"
lines to transfer case:..............5/32" ID, 5/16" OD, L = 7' (total of both lines)
to vacuum reservoir:...............3/16" ID, 5/16" OD, L = 8"
between Tee and vac supply:....7/64" ID, 1/4" OD, L = 3"
Of course I purchased more than I needed. Except for the smallest diameter hose, I ended up with 16" to 22" extra and 9" extra for the smallest ID hose.
You'll likely want to do round up the lengths to the nearest foot so that you can have a little extra to allow yourself to reroute any of your lines if you desire.
Christine
P.S. Here is a schematic of the hose connections posted by mike5511 (post #29) who found it elsewhere on BF.com.
OK Christine I went out to the parts store and bought everything on the list. This weekend I'll attempt to replace all the vacuum tubing. Some of the tubing is really in bad shape although I have no issues at this time. I'd rather do it now instead of when it's really cold outside. Are the different colors representative of the different sizes?
OK Christine I went out to the parts store and bought everything on the list. This weekend I'll attempt to replace all the vacuum tubing. Some of the tubing is really in bad shape although I have no issues at this time. I'd rather do it now instead of when it's really cold outside. Are the different colors representative of the different sizes?
As a bit of insurance, you might also do what I did and use zip-ties as mini hose-clamps on each of the fittings for the hoses.
This is an awesome thread. I've been reading since I got my 04 about horror stories of people sucking trans fluid up into their vacuum lines after the vacuum switch on the transfercase fails; I had NO idea that because mine is a 4 button with auto 4x4 that I didn't even have to worry about that LOL! VERY good to know! Looks like a much more simplified vacuum setup actually compared to the one with the switch on top of the transfercase.
OK Christine I went out to the parts store and bought everything on the list. This weekend I'll attempt to replace all the vacuum tubing. Some of the tubing is really in bad shape although I have no issues at this time. I'd rather do it now instead of when it's really cold outside. Are the different colors representative of the different sizes?
I just noticed the question about the colors representing the size of the hoses. To answer you question, no, at least on purpose. That is someone else's excellent picture that was made before I did my hose measurements.
Update: I'm editing the first post in this thread as I learn of bits of info that I think would be useful to people. Be sure to check it out too if you find this.
It looks like you might have answered your own question on this thread (https://blazerforum.com/forum/2nd-ge...e2/#post696740). But to answer your question, yes the tee and check valve can leak too. These are often available at local parts stores.
