NEED HELP air suspension acting weird

cretecrawler

Well-Known Member
2006 envoy denali swb, pump was running off and on at different times, sometimes I would come out in the morning it would be squatting. Now the aZZ end it way up in the air. Don't know where to start at.
 

northcreek

Well-Known Member
Not trying to drum up a sale, since I'm selling a new compressor unit but, sounds like a compressor failure due to the erratic nature.
The compressor is a stand alone unit (not interfaced with other systems, except for a few inputs) so everything except bags and two position sensors are in there.
The unit is not repairable except for a check valve which doesn't sound like your problem...Mike.
PS I would look at the two sensors near the bags/tires to make sure that they are still in place and both appear to be in the same relative position, the thinking is that maybe something flew-up and damaged one of them.
 
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cretecrawler

Well-Known Member
I was thinking it was a possibly a positioning sensor since is now stuck as high as it will go and not coming back down for almost a week
 

northcreek

Well-Known Member
I was thinking it was a possibly a positioning sensor since is now stuck as high as it will go and not coming back down for almost a week
But, you did originally say that it would be squatting at times which again sounds like compressor logic/valving . The only way I can see the sensors causing this fluctuation is if one is dislodged and flopping around or full of water and shorting out.
 
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cretecrawler

Well-Known Member
But, you did originally say that it would be squatting at times which again sounds like compressor logic/valving . The only way I can see the sensors causing this fluctuation is if one is dislodged and flopping around or full of water and shorting out.
hmmmmmmmm
 
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cretecrawler

Well-Known Member
good day sir Mooseman, on an unrelated/related subject I tried to get to the manuals in your tag line and b4 it would even allow me to sign in to it, the page it went to says this "
Authorization Required

This server could not verify that you are authorized to access the document requested. Either you supplied the wrong credentials (e.g., bad password), or your browser doesn't understand how to supply the credentials required."
Have I done something wrong??

Update: I have gotten it to work, had to switch to Chrome
 
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cretecrawler

Well-Known Member
Not trying to drum up a sale, since I'm selling a new compressor unit but, sounds like a compressor failure due to the erratic nature.
The compressor is a stand alone unit (not interfaced with other systems, except for a few inputs) so everything except bags and two position sensors are in there.
The unit is not repairable except for a check valve which doesn't sound like your problem...Mike.
PS I would look at the two sensors near the bags/tires to make sure that they are still in place and both appear to be in the same relative position, the thinking is that maybe something flew-up and damaged one of them.

I am weighing my options here, and what would be your asking price on the compressor pump that you have
 
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cretecrawler

Well-Known Member
well thank you sir, unfortunately I just came back from the doctor and now the proud owner of a walking boot for Plantar Fasciitis, bone spurs, calcium deposits and degenerative arthritis in both feet so my funds just became nonexistent until I can recoup my med bills. Is there a way to release the pressure in the bags so I can cut back on the nosebleed look and lack of steering ability
 

northcreek

Well-Known Member
Yes, you have to remove the two air lines to the bags (removed at the compressor). "The vehicle must be supported on jack stands".
The rest requires a little air line plumbing, now you must connect those removed lines to a tee, then from the tee you extend a line to an access point and attach a Schrader valve, now it can be filled via air hose to the height you want. Others have done it and there are some old posts here to support what I'm saying. Good luck with those feet....Mike.
ps after this you must "drive a stake" in the compressor, pull the connector or fuse.
 

TequilaWarrior

Well-Known Member
When I "tee'd" mine off - I used the existing schrader valve inside the cargo area. Literally, just removed the air lines from the compressor and tee'd all three together. I do believe I ended up cutting barbs off the end of them because of the type of tee I used. $3 and about 20 minutes worth of work. 4 years now, no issues other than occasionally having to add air - but that's expected. Make sure you are supporting the entirety of the weight of the rear - there is pressure in those bags/lines.
 

northcreek

Well-Known Member
When I "tee'd" mine off - I used the existing schrader valve inside the cargo area. Literally, just removed the air lines from the compressor and tee'd all three together.
That seems like a quick and cost effective way to do this, all for the price of a tee. Perhaps you can provide a source for the tee so the OP can get rolling on this....Mike.
 
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cretecrawler

Well-Known Member
thank you sir TequilaWarrior this is just what I am looking for
When I "tee'd" mine off - I used the existing schrader valve inside the cargo area. Literally, just removed the air lines from the compressor and tee'd all three together. I do believe I ended up cutting barbs off the end of them because of the type of tee I used. $3 and about 20 minutes worth of work. 4 years now, no issues other than occasionally having to add air - but that's expected. Make sure you are supporting the entirety of the weight of the rear - there is pressure in those bags/lines.
does anyone no the size of the air lines??
 

TequilaWarrior

Well-Known Member
I believe the lines are 5/32". I just looked at my amazon & ebay order histories and didn't find anything.

I found the thread I got the idea from on the 'voy site (unfortunately) : https://forums.trailvoy.com/showthread.php?t=30513&highlight=air+suspension

They do mention some McMaster Carr part numbers - you might be able to cross-reference them to a part at your local hardware store.
I seem to remember having to deal with compression rings on the lines as the new tee fitting had compression style couplings - but this was at least 5 maybe 6 years ago(thinking back - I know I said 4 years, but I moved 4 years ago and did this well before then).
This is the part that I see listed in the thread: https://www.mcmaster.com/5779K32 - although I seem to remember mine being brass for some reason. Again, my memory is a little foggy. I know I ended up cutting my air lines after dropping the compressor and I think it was to put the compression rings & compression nuts over the lines before inserting them into the tee.
The thread also mentions using gasket maker to seal up the connections - I did NOT do that and only occasionally have to add air, most notably when there is a significant drop in temperature. My bags actually hold air better after the $5 hack job than when I had the compressor. That dang thing struggled constantly. I attribute what little "droop" I have now to leaky (relatively speaking) bags.
I'll try and crawl under and take a pic if I can tonight. I also seem to recall having left over pieces - perhaps I had to buy a multi-pack to get the Tee fittings I wanted. I'll check my toolbox and spares shelves tonight, too.
 
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cretecrawler

Well-Known Member
I believe the lines are 5/32". I just looked at my amazon & ebay order histories and didn't find anything.

I found the thread I got the idea from on the 'voy site (unfortunately) : https://forums.trailvoy.com/showthread.php?t=30513&highlight=air+suspension

They do mention some McMaster Carr part numbers - you might be able to cross-reference them to a part at your local hardware store.
I seem to remember having to deal with compression rings on the lines as the new tee fitting had compression style couplings - but this was at least 5 maybe 6 years ago(thinking back - I know I said 4 years, but I moved 4 years ago and did this well before then).
This is the part that I see listed in the thread: https://www.mcmaster.com/5779K32 - although I seem to remember mine being brass for some reason. Again, my memory is a little foggy. I know I ended up cutting my air lines after dropping the compressor and I think it was to put the compression rings & compression nuts over the lines before inserting them into the tee.
The thread also mentions using gasket maker to seal up the connections - I did NOT do that and only occasionally have to add air, most notably when there is a significant drop in temperature. My bags actually hold air better after the $5 hack job than when I had the compressor. That dang thing struggled constantly. I attribute what little "droop" I have now to leaky (relatively speaking) bags.
I'll try and crawl under and take a pic if I can tonight. I also seem to recall having left over pieces - perhaps I had to buy a multi-pack to get the Tee fittings I wanted. I'll check my toolbox and spares shelves tonight, too.
THANK YOU SIR
 

northcreek

Well-Known Member
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TequilaWarrior

Well-Known Member
Apparently I used one similar to the one @northcreek just showed a picture of. I didn't find any extras on my spares shelves. Thinking back, I probably ordered it from McMaster-Carr. The ebay one above is not DOT rated (not that anyone's going to check). I think the McMaster-Carr one I got is also not DOT rated, but has a higher max PSI and larger operating temperature range. A tad cheaper, too. But still not DOT approved, FYI.

Here's a pic of it installed:
20190116_081910.jpg
 
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cretecrawler

Well-Known Member
Ok update..... got the fitting, jacked up the truck and found the connector (round rod) arm from the height sensor switch was broken off on the passenger side. Haven't looked at the driver's side yet
Moved the arm back down a little and reinstalled the fuse then the truck suspension lowered by itself. Not having any luck finding just the rod. Any ideas? Also I see in the pics on rock-auto.com that the entire assembly comes with a t-pin locking the sensor arm in one position, is this a shipping application or is that an option to install a pin to keep it in one location?
 

Mooseman

Moderator
I would imagine that T-pin is just for shipping or pre-installation. It has to be able to move with the suspension arm.

Apart from getting a whole new sensor, all I can think of is either JB Weld or finding a used one in a yard.
 
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cretecrawler

Well-Known Member
now to add to the saga, the truck has developed a case of wandering when driving and braking. Feels like the front end is just all over the road. Any suggestions to start looking at?? I understand that this platform seems to eat sway bar bushings and end links.....
 
Yes you will want something like this, you simply push the tubes in and you are all set. I don't think that you will find these at a hardware store as they are mostly used in pneumatic industrial controls.

http://rover.ebay.com/rover/1/711-53200-19255-0/1?icep_ff3=2&toolid=10001&campid=5338077216&icep_item=122794244856View attachment 87083
Is that "t" featured on that link the exact piece, dimensions and all, that I will need? Also, this may be a really dumb question but, how and where did you reinflate the shocks to proper height?
 

TollKeeper

Well-Known Member
What I did on my Avalanche was run a hose from that -T- to a air inflation nipple mounted where ever you want. Then you just take a standard tire air chuck, and inflate them as needed.

It will take a little experimenting to find which air pressure you like, a difference of a couple pounds of air can go from a soft ride, to a firm ride.
 

16vcabman

Well-Known Member
If you replace the sensor, you should re-calibrate both sensors. I made the blocks out of 2x4 and adjusted my sensors. Now the truck sits normal and not stuck in the air. Pump works occasionally but just to hold it at level.
 

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