Hi

My 2004 L322 150,000 miles has had loads of "air susp inactive" faults this year. Fairly exhausting.

It started with a broken height sensor, then I had two more replaced, as suggested by the diagnostics.

The first sensor failure dropped the front down to the stops, which killed the two front air susp struts (old originals), which were replaced.

There are now no faults showing on the diagnostics, but the "air susp inactive" still comes on. It used to clear on its own, randomly, but now it is permanent.

I have replaced the piston ring in the compressor pump twice. No difference.

Before this fault was permanent, the raising was slow when testing it with the wading mode.

I have been advised to try a new compressor.

(1) Is this recommended? I don't want to splash out on a new one, only to find the same problem.

(2) Please can anyone suggest a cheap source of new ones?

(3) What does the relay do? Do these break? Should I replace this too? Could the problem just be related to the relay?

I have searched, and read a few threads here.

Thanks

Even though you've changed the compressor piston ring the bore of the cylinder may be worn and the desiccant in the drier will need changing , a new or recon compressor is probably what's needed , but check for leaks first , there's also an old thread on here somewhere about the valves in the valve block being full of rusty crud ,that may be worth a look aswell . As for cheap they are all around the same price £300 ish new but you might get a recon from somewhere for half the price, I bought a new one 2 years ago and it sorted out the air susp inactive coming up once a fortnight .

Start off with testing the pump, but a pressure gauge and some push fitting and put the gauge direct on the outlet of the pump. I would expect to see 160 psi or there abouts.

someone was offering new pumps on here about 6/7 week's ago as part of a trial, may be worth a search

tomcat59alan said:

someone was offering new pumps on here about 6/7 week's ago as part of a trial, may be worth a search

Click to expand...

They were the later facelift models

2.0_hippo said:

They were the later facelift models

Click to expand...

Mmm,ok, he also said he had P38 pump's as well, did anyone take him up on his offer?

tomcat59alan said:

Mmm,ok, he also said he had P38 pump's as well, did anyone take him up on his offer?

Click to expand...

Would of if he had some for the early L322's

I have bitten the bullit, and bought a new full compressor unit inc housing from Ribble Valley 4X4 via ebay £295 delivered.

I will report back.

Thanks guys.

Incidentally, when I replaced the piston ring in my existing pump, the cylinder was perfectly smooth both vertically and horizontally. It seemed that there was either no wear, or very very even ware.