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You mean for a replacement diaphragm? I don't have direct experience. Normally I try to go for GM parts since I expect to keep my Blazer for a while. The exception for parts are suspension components; e.g. Moog, Proforged, Wix (filters).
Sorry, yes the vacuum diaphragm actuator underneath the battery. Obviously the replacement I installed isn't adequate! Wish I could tell everyone what the brand name is on it so they could avoid it. For informations sake the GM part number is 25031740. The Dorman replacement number is 600-102.
I have a Posi-Lok kit ready to go...might just go that way. I'm tired of throwing parts and money at this thing!
Sorry, yes the vacuum diaphragm actuator underneath the battery. Obviously the replacement I installed isn't adequate! Wish I could tell everyone what the brand name is on it so they could avoid it. For informations sake the GM part number is 25031740. The Dorman replacement number is 600-102.
I have a Posi-Lok kit ready to go...might just go that way. I'm tired of throwing parts and money at this thing!
I would think Dorman could be a decent part. Seeing how easy it is to install this part, you might try going for a GM part for the diaphragm. But the Posi-Lok systems are cool. I might consider doing that someday but for now, I'm happy with the factory setup. (I the "4-button" transfer case so I don't know how the Posi-Lok system would work with that.)
I have wondered about how the Posi-Lok would work with the 4-button. Auto wouldn't work all unless you drove around with the front axle engaged.
anybody have experience here?
You'd better get used to it because it seems to be a fact of life with these rigs. We either fix or modify......LOL
Right? Honestly that's been my only real issue with the little champ. It saves me wear and tear on my 2500, but without 4x4 it's kinda treacherous on the wintertime Montana roads.
For a long time I was under the impression that there was no difference between the 3 and 4 button trucks. I'm learning otherwise, mostly thanks to this thread!
Last edited by Puppytank; 10-07-2018 at 12:43 PM.
Reason: Addition
Right? Honestly that's been my only real issue with the little champ. It saves me wear and tear on my 2500, but without 4x4 it's kinda treacherous on the wintertime Montana roads.
For a long time I was under the impression that there was no difference between the 3 and 4 button trucks. I'm learning otherwise, mostly thanks to this thread!
Puppytank, I'm going to suggest this discussion about the Posi-Lok and diaphragm selection are deserving of its own thread. This could be useful to others especially with respect to use with 3-button vs 4-button transfer cases.
Puppytank, I'm going to suggest this discussion about the Posi-Lok and diaphragm selection are deserving of its own thread. This could be useful to others especially with respect to use with 3-button vs 4-button transfer cases.
agreed Christine. Not sure I'll pursue it anyway....I think you are on to something with the 4-button differences
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" [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.]
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
Edit: 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.
P.S. Here is a schematic of the hose connections posted by mike5511 (post #29) who found it elsewhere on BF.com.
Awesome info on this thread I found the vacuum supply from the manifold and to the reservoir are completely rotted. That being said is the reservoir hose go any further into the fender or just stop at where I can feel it?
Puppytank, There is a little nipple in the fender wall that you can just feel the end of (at least on mine). It was tough for me to get my hand in there to get the hose slid over the nipple but I got it. I couldn't see it, it was all done by feel.
Puppytank, There is a little nipple in the fender wall that you can just feel the end of (at least on mine). It was tough for me to get my hand in there to get the hose slid over the nipple but I got it. I couldn't see it, it was all done by feel.
That's what I was thinking just wanted to verify before I started tearing into it.
10-07-2018, 10:31 AM
Sorry, yes
