2004 LeSabre - Compressor for rear shocks

[Dan Cluley]

I know this is more late-model than most here, but I'm hoping someone has some experience with this.

 

My LeSabre has the automatic leveling system, but it isn't holding air.  Over the winter I had noticed the compressor running every few minutes, so attacked the project last month.  Replaced both shocks (Monroe MA822) and the plastic air lines (2 of the Monroe AK29 kits had enough pieces) but still had the problem.

 

If I disconnect the lines from the compressor & use a hobby compressor through a schrader valve, the lines & shocks will hold air pressure for a couple of days, so I'm reasonably confident that those are ok, and that the air leak is in the compressor assembly itself.  Honestly, if it would hold air longer than a few days, I'd call it good, but having to put air in regularly is going to get old fast.

 

I pulled the compressor assembly and bench testing it, I think I know what is going on, but not 100% sure & not sure if it is something that can be fixed.

 

Putting power to the one pair of wires causes the compressor to run, and air comes out.

 

Putting power to the other pair causes the valve area to make a clicking noise.

 

 

If I understand correctly, when the shocks need air, the compressor runs & pushes air through the valve, through connection 4 into the reservoir & then through connection 5 into the lines.

 

When the shocks need less air, the valve opens and lets air from the reservoir out through connection 3 and out through connection 1 (that hose connects to a fitting in the frame rail)

 

By process of elimination, I am assuming that connection 2 is the air intake for the compressor although I cant see how it gets from there to the head.

 

If any of that is incorrect, please let me know.

 

I tried running the compressor with the Y hose disconnected, and there is a little air flow at connector 5 and more air flow at connection 3.  I assume this means the valve is not sealing properly in some fashion.  Does that seem right?

 

I see lots of bolt heads, but before I start taking things apart, is this likely to be repairable, or do I just bite the bullet and replace the whole thing.

[JohnD1956]

With no similar experience here I think your explanation of the process is logical. And since you have airflow it appears your assessment that the valve is sticking is correct.  I dont see how that valve is removable from the bracket for any service. And I dont see any mechanical means for sensing the level of the car. 

As such, if that valve cannot be serviced I suspect you have to get a new one. 

And before I did that I might try some type of lubricant soak by introducing some 50/50 trans fluid acetone mix through 1 and 5 and then let it sit for a week or more. 

Is there a mechanical link to determine the level?   That may need some attention too. 

 

Good luck

[Dan Cluley]

The sensor is a separate component attached to the frame and left rear control arm.   It sends a signal through one of the computers to a pair of relays that control the compressor and the release valve.  I'm pretty sure that part is working properly.

[Dan Cluley]

Thanks for the info. The short answer is I found a used one for a reasonable price that is supposed to have been tested. I guess I'll find out next week when it arrives.  Will probably try to disassemble the old one to see what I find.

Having spent too much time researching this, I'm going to include this info that may help someone else who finds this post.

It looks like the same basic compressor unit was used on the C, H & G body cars from 1985-2011. Sometime around 95-96? they changed the air out fitting on the dryer. There are a number of different mounting brackets depending on year and car. There are either 3 or 4 different electrical connector types, but I suspect that the compressor & valve can be interchanged all through that 25 years.

Dorman numbers - some or all of these are available new in 2023.
949-033 - 1985-1995
949-035 - 1996-1999
949-015 - 1997-2005 - There is overlap '97-99 I think the H bodies used the older style, while the G bodies used the new?
949-009 - 2006-2011

GM numbers - I think these have all been discontinued, so used or find in the back of someone's warehouse.

22153135 - 1985-1995
22153137 - 1985-1995

12494811 - 1997-2005
22153457 - 1997-2005
22189726 - 1997-2005

15811960 - 2006-2011
25806015 - 2006-2011

Just the head & valve assembly was also available separately from GM

12494810
12494812
22153611
22177672

I did not find enough information to know if there are differences, or if these are just part number changes over the years.

[NTX5467]

Thanks for the information.  The 2005 LeSabre Limited I bought about 5 years ago, with about 88K miles on it then, the first start of the day, I could hear the compressor run a little bit to get things re-pressurized.  I figured this was normal.  I know that one of the rear shocks had already been replaced when I bought the car, but not sure which one.

 

The price of the rear shocks is more than insane from GM AND I also suspect they are not "new production" but really NOS in the GM warehouse, considering the dwindling numbers of cars which use those shocks.  BTAIM

 

Used to be that when the OEMs discontinued something, they'd cut the price drastically to get them sold on a "closeout sale", but not it seems that the price is inflated such that any "obsolete parts scrappage" write-off amounts are maximized.  There are several examples I've happened across over the years which tend to support that observation.

 

I'm suspecting the base units are pretty much all the same.  Not sure why they would change connectors and such?  Of course, the related mounting hardware would be unique to the particular vehicle, as mentioned.

 

Thanks again,

NTX5467

Edited July 1, 2023 by NTX5467 (see edit history)

[Dan Cluley]

1 hour ago, NTX5467 said:

 

The price of the rear shocks is more than insane from GM AND I also suspect they are not "new production" but really NOS in the GM warehouse, considering the dwindling numbers of cars which use those shocks.  BTAIM

 

Check Monroe MA 822. They should be an exact fit and cost a fraction of what the GM ones do

[60FlatTop]

16 hours ago, NTX5467 said:

Used to be that when the OEMs discontinued something, they'd cut the price drastically to get them sold on a "closeout sale", but not it seems that the price is inflated such that any "obsolete parts scrappage" write-off amounts are maximized.  There are several examples I've happened across over the years which tend to support that observation.

I remember things about that practice as I was growing up. Parts used to find their way into the hobby that way. Seems like there was a general 8 year rule attached to it.

 

Today I am most reminded of it when looking through Rock Auto parts availability. Being mostly a GM person I see a lot of items to reinforce the idea.

 

In 2011 I used a lot of original GM parts going through my 1986 Park Avenue. That included complete factory bent and packaged fuel lines and hoses all the way from the tank with correct hoses. When I bought them I though prior to computer databases and marketing those parts would have been scrapped on all but the rarest occasions. We got a lot of parts for my 25 year old malaise on that job.

[NTX5467]

Where the seemingly-inflated MSRP parts prices really hit home to me, an older gentleman came in one day looking for the a/c control head for his wife's 4-door S-Blazer.  When they were putting upscale options on those vehicles to make them more like smaller C/K vehicles.  That semi-automatic a/c control head was over $500.00 for what was then a 20 year old vehicle.  He respectfully said he could not afford that and thanked us for looking.  Then he was going to an area salvage yard.

 

Later, in looking around during slack time, I looked at OEM wheels for an Olds Intrigue.  They were priced as if they were a 2010 new vehicle.  NO insurance company might pay for a new replacement wheel for such a car, due to its age at that time.  Few people were doing OEM-correct restorations, so whom might the ultimate customer be?  More money for scrap parts write-off, apparently.

 

So many actions of the OEMs seem out of whack, but are most probably a part of an orchestrated orientation to result in the parts (or complete vehicles) not moving from inventory.  So, no sales = no new parts being built = parts ultimately scrapped/vehicles ultimately discontinued.  All results from their orchestrations, no more no less.

 

In the years prior to the Camaros first "vacation", GM invested little money in the car for about three model years.  Sales brochures were lackluster.  THEN when the uproar from Camaro enthusiasts overwhelmed GM, that next Camaro brochure had some serious money spent on it.  Many pictures were "poster quality" shots, by observation.  There were some hidden-from public-view side issues at play that first time, which came out as time progressed back then.  Ford has done some similar things, too.

 

NTX5467

[60FlatTop]

On 7/2/2023 at 4:18 PM, NTX5467 said:

THEN when the uproar from Camaro enthusiasts overwhelmed GM, that next Camaro brochure had some serious money spent on it.  Many pictures were "poster quality" shots, by observation. 

Around 2005-06 I bought a few decades of left over sales promotion items from a local retiring Chevy sales manager. From display cards to a few billboards. I remember how nice those Camaro posters were. At the time I was selling them on Ebay. I bought a cheap Camaro and listed it to drive traffic to my sales items. "Please check out my brochures and posters listed in other auctions". I sold everything.