After installing ball joints the front air suspension went flat and the pump won't kick on to pump up the struts.The pump was tested and operates. Fuses and relays were checked.

Any ideas.....???

As a last resort, how do Iblock the car up off its wheels to get it to a shop...????

Thanx.

 

I have the identical problem on my 2000 s500. Just the front struts are flat, no obvious signs of damage. The compressor does run but it sounds weak. The dash warning about the car being too low comes on then the message about the car rising comes on but the car never rises.Let me know if you find out anything as I am almost ready to see the dealer($$$gulp!)

 

Air suspension is in principle quite straight forward.
All you need is air pressure.
Pressure is supplied by the pump.
This pressure is limited by a pressure sensitive cut out.
The pressure is distributed by a valve block with its own pressure sensor.
The air is distributed and subject to a leak on the lines OR in the strut (usually the top mounting) the air will cause the piston in the strut to lift the car.
Height is sensed by sensors on the axles attached by little plastic links.

Now none of this has to be disturbed to change the lower front ball joints.

However when the suspension is disconnected the struts "dangle" and this could have been the last straw to an about to fail top strut mount.

If the car is OK at rear and low at front it suggests the valve block or height sensors but the valve block is extremely reliable and the chamnces of this going coincident with the ball joint change VERY low,

I suspect that your pump is not working correctly. May run but not deliver the correct pressure for whatever reaqson.

Now all of this CAN be done as DIY BUT the easy way is to get the dealer to use SDS Diagnostics because they can test each component in the system thru commands to the computer and do things like raise the LHF height on its own (i.e. override the normal raise all corners command. This process allows the faulty component to be isolated without need for disconnecting lines and using pressure gauges etc etc.

Now how do I know all of this.

Well recently I had a similar problem.

I tested EVERYTHING that I considered a possibility but couldn't find the fault with my limited test gear.

In the end I had to get the dealer to look. Of course they didn't accept my word as to the fact that everything was OK. I agreed to pay for an SDS Quick Test report £25. 5 hours later they announced they had found the problem but they would not charge extra because thay hadn't previously encountered the fault and they were very interested.

The fault was that after a recent journey with heavy load in the boot the rear end was running high. I eventually lowered it by letting air out of the system but the system wouldn't then raise the car to the correct height. The pump would run but somehow it never raised the pressure adequately so I suspected the pump pressure valve but this appeared OK.

The problem turned out to be a bad connection WITHIN the wire harness (about 6" from the plug onto the pump pressure sensor. When the joint got warm it changed the signal from the pump pressure sensor and stopped the pump prematurely. The bad join was due to salt solution having travelled thru capillary action up the harness wires. Solution. Resplice the problem area. He presto.

Mind you to get to this point the dealer had changed the pump, valve block and pressure sensors since they too had tested them and found them OK BUT SOMETHING had to be wrong.

Could have been VERY EXPENSIVE.

I actually drove the car to the dealer (mile or so away) since my car is on standard 225/60-16 tyres vs wider ones and my car was not FULLY onto the bump stops. WARNING: WARNING: I DO NOT SUGGEST YOU DO THE SAME. Although the tyres should not be touching anything whilst the point straight ahead it is a different matter when you apply lock. If you can get some air into the front struts then maybe.

Looks like you need a flatbed truck (if you can get the car onto it)

Good luck.

Stuart

 

You accurately described my circumstances. After further inspection I discovered that both front strut tops are cracked.

 

Hi,

Need to locate the after market repair kit (posts on this forum have previously referred to where to obtain etc.) otherwise this is a VERY expensive repair.

good luck.

stuart

 

there is an original part for the air suspension repair kit but you will need a special tool to dismantle the top diaphram

 

The 2000 S500 is a full 765 pounds lighter than the previous year, and even when. Elimination of double paned windows, and the air suspension system

 

For all that are interested I have repaired my air suspension problem. As listed earlier in this thread my front struts went completely flat. The rear was fine and I could hear thecompressor working, although it sounded weak. I tried to repair thecompressor and clean out the carbon buildup on the inside. I reinstalled the cleaned up unit back in my car but the result was identical, noise butno lift. As a side note, I inspected the top of the struts and could not find a crack anywhere. The valve unit on top of the compressor had been replaced about a year ago due to a leak in the valve body (you could hear the hissing). Thismeant to me that this part is prone to fail or it could mean that it was an almost new part and was unlikely to fail again. I took a chance and changed the compressor. To my delight the car started rising immediately and I have not had any problems since. The compressor replacement is not a difficult job, but it is labor intensive. You must remove the passenger front wheel and mudguard, the bottom splash guard, and perform the job while laying underneath the vehicle (unless you have a lift). The only tools required were a 10mm and 8mm socket wrench and a set of pliers. I would be happy to share the details of the job if asked. Adam.

 

Hello all, tell me in your MB experience. Should a retire poor man invest his $349.00 a month for 60 months for a 2000 S500 MB white with 119,415 miles from a dealer. I bargain it for $13,500.00 with high interest because of bad credit makes my payment so much but with $0 down payment. The only physical damage is the right visor. I am 63 yrs old and this is my dream car. I finish my 00 Nissan Maxima payment in March with the same $349.00 a month for 7 years. So, tell me your opinion, by the way it will save as a second car because my Maxima only carry 76,178 miles. Reply and God bless.
PS: Do not hesitate to tell me if I am crazy?

 

@friac40.
Dream Car. Yes but...
Nightmare repair costs (should anything go wrong) unless you are a DIY'er
At 113k miles a number of things MAY need attention dependent upon previous use, care and luck etc.

Engine/Trans should be OK but suspension (ball joints and airmatic struts on V8) + assorted electrics will likely need attention.
Ensure you have a good warranty or at least have a pot of gold incase a rainy day comes along.

Can't make any judgement regarding the required price of the car. Not familiar with your market.