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Hello... I can not for the life of me find where the green intake manifold vacuum line goes. I've been looking for at least 30 minutes. hahaha. My vacuum line was running in between a tube that runs to the intake and the valve cover... it was just loose sitting there.
Can someone send a pic of where on the intake that line should run? Would be super helpful.
For now, this is the best I can do in terms of picture. The hose connects to the intake manifold at a fitting on the left (drivers's) side of the intake plenum (upper intake manifold) near the outer edge about half-way from front to back.
If this doesn't help reply here or PM me. Good Luck!
Why do i have a second line coming out of the intake supply?
Originally Posted by christine_208
[updated continually]
Hi all,
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) (see below for 3-button transfer case)
Intake supply line:..............................................7/32" ID, 7/16" OD, L = 20" [ light green line in schematic] lines to transfer case:.........................................5/32" ID, 5/16" OD, L = 7' (total of both lines) [ blue and red lines in schematic] to vacuum reservoir:...........................................3/16" ID, 5/16" OD, L = 8" [ light blue line in schematic] between Tee and one-way valve (vac supply):......7/64" ID, 1/4" OD, L = 3" [ grey line in schematic]
(The brown line in the schematic is a cable, not vacuum line.)
Regarding the hose connection to the vacuum diaphragm for the front axle located under the battery tray: The OD of the hose that goes to the vacuum actuator for the front axle is as important as the ID. This is because this hose connects to the actuator using a FEMALE fitting, not a male (i.e. a nipple) fitting. And as we all know, not all hoses with the same ID have the same OD. I lucked out with this one as I did not know that when I purchased my hoses.
Of course I purchased more hose 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
Hint: If you want a bit of extra insurance, you might do what I did and use zip-ties as mini hose-clamps where each of the hoses attach to the nipples.
Here is a schematic of the hose connections posted by mike5511 (post #29) who found it elsewhere on BF.com.
This information is from Fitz (post 23):
P.S. I am continually updating this first post in this thread with additional details and ideas others have contributed.
Originally Posted by christine_208
I don't think it would make much of a difference if the new size is not too different from the original.
Please help christine 208!! im new to this forum and i have a second vacuum line coming out of the intake supply on my blazer 2000 4x4 3button 4 wheel drive. Is it a breather hose maybe? Everything points out to me that the pcv is under the big plastic hose that goes from the air filter to the throttle body. That second hose has like a plastic fitting at the end and i found it pointing down
While this is brought up...what is that dark green line from the actuator to the transfer case?
That line is a cable that is pulled by the actuator that lives under the battery tray to which the blue line goes. When pulled, it pulls on a yoke that slides a gear along the right output axle axis so that the right wheel is engaged with the front differential.
Please help christine 208!! im new to this forum and i have a second vacuum line coming out of the intake supply on my blazer 2000 4x4 3button 4 wheel drive. Is it a breather hose maybe? Everything points out to me that the pcv is under the big plastic hose that goes from the air filter to the throttle body. That second hose has like a plastic fitting at the end and i found it pointing down
Off the top of my head, I believe you could be correctly referring to the connect to the PCV. There is a right-angle hose that attaches to it. It is best to take the engine air inlet off the top of the engine so that you can see everything easier.
There should be no hoses exposed to atmosphere from the engine. The only hoses that are vented to atmosphere that I know of are the ones for the front and rear axles.
Off the top of my head, I believe you could be correctly referring to the connect to the PCV. There is a right-angle hose that attaches to it. It is best to take the engine air inlet off the top of the engine so that you can see everything easier.
There should be no hoses exposed to atmosphere from the engine. The only hoses that are vented to atmosphere that I know of are the ones for the front and rear axles.
Christine 208 thats whats hooked up to the pcv. But why both hoses and where does that second one go to? Or can i block it off maybe??
i have a question,
on my i guess bled door switch / ****, when i am switching from floor to defrost to vent, my vent only blows hot as it is either switching to it or away from it when it is actually blowing out of the vent it only blows cool air. but, again when it is moving off vent to any other position that is when i feel the actual hot air for a split second, and the top and bottom both blow hot and suggestions on what to try ?
i have a question,
on my i guess bled door switch / ****, when i am switching from floor to defrost to vent, my vent only blows hot as it is either switching to it or away from it when it is actually blowing out of the vent it only blows cool air. but, again when it is moving off vent to any other position that is when i feel the actual hot air for a split second, and the top and bottom both blow hot and suggestions on what to try ?
In the future it would be best if you used proper punctuation and capitalization as it was hard to read your question.
But to your question. I would suggest you look for one of the vacuum diagrams for the HVAC system in our Blazers. There you will see that the air ducts are controlled by vacuum actuators. These not only direct to where the air is directed to flow but I believe there is at least one that also works with how the air is ducted for the heating/cooling of it.
Problems with the HVAC system can happen even if there is only a small leak. As such, it is a good idea to replace all of the under-hood vacuum hoses once the vehicle gets to about 15 y.o.
06-25-2020, 01:56 PM
