air suspension

Hi all,
looking for advice, my dhse, when left for a few days seems to take forever to get up to driving height, 10-15 mins. I had a bag (I think) replaced when I first bought car 2yrs ago cos every morning one side would be leaning. Maybe there are filters I should be cleaning or maintainence I should be doing. Any help? Cheers.

Sounds like a worn compressor to me. Before starting in the morning, open the bonnet and then open the EAS box. Its on the passenger side above the wheel. Start the vehicle and leave the door open and then time how long the pump runs, you will know when the pump is running as you will hear it running OR you can put your hand on it and feel it running.

Should not run for more than around 8 minutes. This is roughly the amount of time it takes fill a completely empty air tank. Usually the tank will have been kept topped up with air as you drive so the pump shouldn't run for more than 2 to 3 minutes.

Do you know if the compressor has ever been replaced or refurbished, if it hasn't and the pump does run for a long time then suspect a worn compressor seal. You can get replacement seals online, complete compressor refurbish kits or you can go and buy a new compressor.

A far less likely scenario could be that you have a leak somewhere. You can check for this with a little plant sprayer type thing and set it to the mist setting. Wait until the compressor has stopped running and fill up the sprayer with soapy water and then spray on the air line connections that go into the EAS box (DONT SPRAY INSIDE THE BOX) and look for any bubbling. Also check the air tank air line connection (the tank is under the vehicle beneath the driver, inside the frame rail). Then close the door and let the vehicle come up to height, it should come up straight away assuming that the compressor can fill the tank ok. With it up to height, get underneath the vehicle and then spray the rubber airbags. Look for any bubbling from them as well. This could also be a cause of your problems, however, I wouldn't expect you to be able to hold height at all if your bags were leaking.

Check the air compressor and see what you find and post back with results.

-Wills

cheers Wills, will try your advice.

Look for leaks. Soapy water test on the outside of the valve block and the fittings for dryer and bags. A normal healthy system should not loose more than approximately 1 inch overnight.

i had same prob, my compressor would run for ages trying to fill tank, or with the doors all shut it would take ages to lift!
i brought a new piston assembly complete with seal, piston, crank and cylinder, the whole lot, £80, fitted it in 20 mins and now its fine. the state of the old piston seal was amazing, i was suprised it worked at all!!

p.s. i found that a slow puncture dont help as the suspension try's to self level and lowers it self due to one of the tyre's being softer.

Might depend on how long your normal journeys are too! If you have only been driving round town and dropping into access height the reservoir will empty and unless you go over 2000rpm the compressor will not kick in. I occasionally get the same problem, so don't tend to use access height unless the wife is with me!

Ed Foster said:

Might depend on how long your normal journeys are too! If you have only been driving round town and dropping into access height the reservoir will empty and unless you go over 2000rpm the compressor will not kick in. I occasionally get the same problem, so don't tend to use access height unless the wife is with me!

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fistly.
the tank dont empty when dropping, the air in it is then used to push it back to standard ride hight therefor the pressure will drop and the compressor will kick in to put the pressure back to normal, the tank wont empty completely, just a bit!...................

secondly.
my compressor will kick in and out as required at idle speed, there is no relationship between engine speed and the compressor running, as long as the engine is running.
the engine dont have to be taken over 2000rpm once for i to kick in either..............

i would advise you have your EAS checked if the compressor only runs when engine speed is 2000rpm+ as its defo not right!
the pressure in the tank should be enough to drop to access mode and return 2 maybe 3 times to normal hight without the compressor running, (unpluged) mine does anyway!

Okay....well seems to work with mine........guess I had better check everything is alright then....not getting any error messages!....gulp

Just found this on another site! Does this make sense?

Normal Operation which Might Seem Faulty: The air suspension is controlled by an ECU under the drivers seat, which operates a solenoid valve block in the engine compartment. The ECU has a fairly low IQ, and wastes a lot of air by raising and lowering each corner constantly trying to level the vehicle. So the system's compressor turns on frequently. Another cause of its frequent running is the fact that the pressure switch is located remotely from the air tank so the pressure drop in the thin air line makes it think more air is needed. Another annoying feature that is said to be normal happens whenever the vehicle is parked on anything but a perfectly flat surface. The system tries to level itself by lowering all springs to the height of the lowest one, then realizes it is still not level so it lowers the first spring as well and starts the whole cycle over again until the vehicle ends up on the bump stops. This rather unintelligent strategy is particularly annoying off pavement, since the ground is nearly always uneven. So don't park where there is a big rock or other obstacle under the vehicle! If you want to stop in such a spot temporarily, either leave the engine running, or inhibit the system's unintelligent operation by leaving a door or the tailgate open. Pressing the manual inhibit switch on the dash also helps reduce or ewliminate this behaviour. Finally, whether on or off road, the ECU often lets so much air out of the system overnight that when you come out in the morning it can take several minutes for the suspension to raise itself up again to normal height. This is not supposed to happen but often does, even though the suspension checks out normally on the dealer's diagnostic apparatus

Ed Foster said:

Okay....well seems to work with mine........guess I had better check everything is alright then....not getting any error messages!....gulp

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it may be worth while,you may be lucky and catch something before it becomes a real prob!
if i start mine with no throttle the compressor kicks in and its up in 2-3 minutes when its left for a week or so and on bump stops!

also beware of slow puntures!
mine used to drop on even ground and when i found and repaired a slow puncture it stopped doing it instantly.