L322 EAS having trouble lifting heavy weights.

[davus]

Hi Guys,

Merry xmas and happy new year to everyone!.

Ive got a bit of a problem with the airbag suspension in my 2002 L322. For some reason it has started having trouble lifting heavy weights.

I have a whittley cruisemaster 700 cruiser boat. Its right on the limit of tow weight at 3.5 tons. Cant remember the downforce on the tow ball, but i do remember that its right on the limit there too.

Anyway, normally i reverse the car up to the trailer and then just use the airnag suspension to lift the car to the highest "offroad" setting. This gives me enough clearance to swing the jockey wheel into its upright position.

About a week ago i went to hook the trailer up, and the car wouldnt lift to the highest setting. Below are a few pertinent points.

1) without any weight on the towball, the car will lift fine to all heights.
2) If i lift the car to the highest setting, and then lower the trailer onto the ball, the car does not want to then self level.
3) if i set the height to the "normal" height, lower the trailer onto the ball, and then try to lift to the max height, the air compressor comes on, and the front lifts no problems. However the rear wont. It slowly tries to go up, but in reality it doesnt.
4) eventually it will get to the point where it thinks it is high enough (ie the indicator light stops flashing and is solid on the highest point), however the car at the rear physically hasnt lifted that high.
5) there are no errors coming up at all. I have an AllComms which i have plugged in, and no faults are coming up at all.

Does anyone have any pointers as to what the problem might be, or where to start looking?.

Many thanks.

Dave

[Blade74]

I have no idea but it kinda sounds like the compressor can't create the pressure required.
In sure someone will have more of an idea but it sounds like the compressor to me?
Does the car maintain height when parked up overnight or a few days?
Or could there be a slow leak somewhere?

[davus]

Hi Blade,

I "think" the compressor is OK. I have two of them.

One has been working seemingly OK for quite a while. The other i rebuilt about 6 months ago with one of bag piping andy's rebuild kits.

If i leave the car sitting for a few days and then get in a start it, the front of the car does come up about an inch. I didnt think i leak this slow would be enough to stop it from lifting the rear. And even then, i would have thought i leak in the front would effect the lifting of the rear?.

Dave

[Homestar]

My initial thought was the compressor too. The other symptoms make me think it could be something else though. The fact that the flashing light goes off to say it has reached the required height, but it hasn't gone up at the back is a bit strange. The only time that happened to me was when I has a stuffed height sensor, but that threw a fault.

With your Allcomm, can you see the individual heights of each wheel? If so, check to see if they are all saying the right thing, could be a sensor, but I'm leaning towards the compressor - when was the last time you replaced it? If it's original, then it will be very long in the tooth. I'm on my second one, and that is starting to get a bit slow.

[davus]

hi bacicat,

Not sure if the answers in my above response will help?. I think i responded about the same time as you!.

Dave

[Blade74]

There's obviously 3 different pressures required for the three different heights.
Something may be limiting the pressure required to reach max height or the pressure required for leveling the car with weight on the ball.
Maybe the compressor can't create the pressure required.
Although you would expect that there is a cut out once the compressor has reached it and if it didn't it would just try and keep pumping and never get there.
So maybe it's the pressure cutout sensor which I assume is built into the compressor.
Maybe it's cutting out too soon at too low a pressure?
Sorry just throwing out ideas

[Homestar]

Sorry for the hijack But I've just had something similar happen to mine today... :D

Got it back on the road today after months sitting in a mates workshop (my fault entirely for not making the time to sort the issues) but after fully rebuilding the arse end as it clunked and squeaked and clicked (cv's - easy fix if they just start to click - swap them side to side, they are identical part numbers on the back ;)) but when I recommissioned the EAS (the whole system was deflated using my IID tool) I now find that I cannot get it to off-road height. It starts to go up, but doesn't get there....

I know my compressor is a bit weak, what pressure should be in the system? I watch it go up to 138psi which I think is a bit low.

Any thoughts?

[davus]

thanks guys for all the replies.

I can see the heights of the wheels, however im not quite sure how to read it.

Does anyone know if the allcomms can show the pressure in the EAS system?. I cant seem to find it anywhere?.

bacicat - how are you seeing the pressure in your system?

Dave

[Homestar]

I have a GAP Diagnostics IID tool. In the menu you can go to 'live values' and look at any ecu for its data. Was also looking at Cabin, AC and external temps in the hvac system. :)

Height values range from negative a bit to positive a bit - it varies from wheel to wheel. I think I saw -35 when it was at access height and +65 when trying to get to off road height, but what relationship this is to anything, I'm not sure. I probably need to calibrate mine, but I haven't read up on that yet, so don't want to go stuffing with it until I know what I'm doing. :D

[gavinwibrow]

Sounds like zero is either highway or normal suburban height, then up and down for the others

[harlie]

Standard height is 0, other heights are offset from standard.

If the compressor is getting lazy it will take longer, if you have a freshly rebuilt compressor, why would you not try it? Takes 5 mins to swap...

When the indicator shows that it is at offroad height, what is the live value from the 2 rear sensors?

Gav - if you have changed bushes/balljoints ect you should go through the calibration procedure - it sounds more painful than it is.

[eumundimerc]

Hi did you fix problem

I have same Billy

[donrover0]

Does sound like compressor tired or cutout switch not allowing to full pressure.
The back airbags need more pressure than front for same height. So maybe thats why yours will lift front but not back.
Ive rigged up 4 individual wheel air valves under bonnet and mucking around I've found my old wshop compressor at 110 psi will easily lift front high but not back.

[Homestar]

Yeah, you need at least 140PSI to get the arse off the ground.