Under-hood vacuum hose replace
#71
Are you sure it cannot hold vacuum? Have you checked it and the one-way valve?
You might consider a vacuum canister from a 1st gen Blazer because I think they are remotely mounted and not inside the fender.
#73
I have a 2004 Blazer 3 button. I have replaced the majority of the vacuum lines described but when I go into 4 wd I get a p0445 error code. A large leak but only when I switch. Originally it did it but I lost 4wd. I didn't have enough vacuum to work actuator. Any ideas where to start?
#74
I have a 2004 Blazer 3 button. I have replaced the majority of the vacuum lines described but when I go into 4 wd I get a p0445 error code. A large leak but only when I switch. Originally it did it but I lost 4wd. I didn't have enough vacuum to work actuator. Any ideas where to start?
#75
Thanks I have checked the vacuum tank I'll look for the line to the axle next
#76
Out of curiosity, does the size of the line make a huge difference on its performance? I replaced the small line between the T and the one way valve with a piece of 5/32 I thought matched it in size, would this cause any issues?
#77
#78
[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.
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.
#79
Your diagram shows a "vacuum reservoir". It appears to be in the fender/wheelwell area. My 02 Blazer, 4WD, has no such animal in that location. But there is a vacuum hose that I can't locate a connection for. When I started taking the rotted hose off, all of it came off in my hand and I didn't see where it came off from. What am I missing?
#80
My problem now is that the hard plastic tubing's are breaking off almost at the touch. Can that stuff be replaced? I know I'm working with an 18 year old vehicle, but it's my 2020! I gotta fix this thing.