Air suspension problem, I know not that again

[captiva]

Fault is inact suspension light plus very hard to get it to off road height pump goes forever and doesn't get there
4.8 is 2005 and done the air bags, pump relay, overhauled pump and that improved it so thought I was on the right track, fitted new pump and its the same although the light hasn't come on yet. I thought the reservoir tanks were supposed to hold enough air to raise vehicle once without using pump. Original code was 74 accumulator requesting filling.

One last observation , are the rear ride height sensors supposed to be at an angle as the front ones are dead level.

Any help would be appreciated as it is driving me nuts!!

[Brandon002]

Have you checked for a leak in any of the air lines?

[captiva]

Originally Posted by Brandon002

Have you checked for a leak in any of the air lines?

I haven't done the soapy water test yet, I just visually inspected them and wiggled them

[TerminatorX5]

one basic observation - the level can be lowered when the engine is off and all doors are closed (hatch can be opened) and the "lower" command recieved while the car was running... the level can NOT be raised when the engine is NOT running, and the doors still need to be shut...

so, if it still behaves as you describe, further digging is warranted...

[captiva]

Whenever I try it, the engine is running and doors closed, it will go from low to normal but with pump running considerably but does not go from normal to high easily, it struggles and I usually give up as I am concerned about stressing or overheating the pump

[TerminatorX5]

something is obstructing the passage of air - can you hear any hissing or whistling if you are outside the car while the pump is pumping?

[captiva]

Originally Posted by TerminatorX5

something is obstructing the passage of air - can you hear any hissing or whistling if you are outside the car while the pump is pumping?

No nothing

[Ricky Bobby]

Originally Posted by captiva

Fault is inact suspension light plus very hard to get it to off road height pump goes forever and doesn't get there
4.8 is 2005 and done the air bags, pump relay, overhauled pump and that improved it so thought I was on the right track, fitted new pump and its the same although the light hasn't come on yet. I thought the reservoir tanks were supposed to hold enough air to raise vehicle once without using pump. Original code was 74 accumulator requesting filling.

One last observation , are the rear ride height sensors supposed to be at an angle as the front ones are dead level.

Any help would be appreciated as it is driving me nuts!!

Your accumulator 74 code dictates an air compressor (pump) burnt out of spec. Did you actually replace the whole pump? Explain this overhaul you did? Did you use the seal repair kit available to refurbish the pump, or did you just buy a used pump and swap them out?

Did you reset the faults in the module with GT1/DIS/INPA after "overhauling the pump"? If you didn't, your old faults will be stored and you'll still have an error on the dash.


Explain these questions and I should be able to help you figure it out, I swear I should make a sticky thread about repairing the air suspension, I must get pm's once a week about it ever since mine was fixed.

[captiva]

Originally Posted by Ricky Bobby

Your accumulator 74 code dictates an air compressor (pump) burnt out of spec. Did you actually replace the whole pump? Explain this overhaul you did? Did you use the seal repair kit available to refurbish the pump, or did you just buy a used pump and swap them out?

Did you reset the faults in the module with GT1/DIS/INPA after "overhauling the pump"? If you didn't, your old faults will be stored and you'll still have an error on the dash.


Explain these questions and I should be able to help you figure it out, I swear I should make a sticky thread about repairing the air suspension, I must get pm's once a week about it ever since mine was fixed.

I got the piston ring and seal from England and fitted that and there was an improvement so went on to buy replacement pump from Arnott and although the light has not come on YET pump goes crazy when I try to select high level. Have a DIS 44 so cleared any codes

[Ricky Bobby]

Originally Posted by captiva

Fault is inact suspension light plus very hard to get it to off road height pump goes forever and doesn't get there

This is the key statement which tells me your air pump, whether replaced with a new one or not, still has issues. When I replaced mine a year and a half ago, I bought a used pump off a member on here which came off a 30k mile X, so it was fairly new. however, I would not recommend a highly used air pump because the seal does have a tendency to degrade and that is why it can't fill the bags quick enough.

Here is a link to the air pump repair kit that you need to install on your air pump to hold the pressure better, it comes from jolly ol' England:

Mercedes E Class s Class Wabco Air Suspension Compressor Pump Seal Repair Kit | eBay

Install it on your pump, reinstall in the car, and reset the faults. Your air suspension should be fine after that (with any issues relating to the above)