2002 Vario 814D - Air suspension fault

Omfinity

New Member
Joined
Sep 15, 2012
Messages
6
Reaction score
0
Location
Caerphilly
Your Mercedes
Vario 814D 2002
Hello everybody,

We have just purchased a 2002 Vario 814D Ex-Library van fitted with air suspension on the rear axle.

200 miles into ownership it has developed and interesting fault.:confused:

When stationary, with the engine running, the rear of the vehicle is raising and lowering every 10 seconds or so. It does not go to the ground but probably about half way down.... The air system does not appear to have any leaks but cannot be sure as the system appears to release any excess air as a matter of course..

Has anybody had a similar fault or experience and perhaps offer some guidance ahead of heading off to a MB dealership..

Thank you..
 

Roxie

Senior Member
Joined
Sep 20, 2011
Messages
814
Reaction score
15
Location
Lincolnshire
Your Mercedes
C Class 350CDI 2012
It is probably losing air from the air bags or the exhaust port on the control valve. If you cannot hear anything then spray soapy water round anything that might leak.
 
OP
O

Omfinity

New Member
Joined
Sep 15, 2012
Messages
6
Reaction score
0
Location
Caerphilly
Your Mercedes
Vario 814D 2002
  • Thread Starter
  • Thread starter
  • #3
Thanks Roxie..

I have checked for leaks as you suggested, nothing apparent! The Relief valve on the suspension air control valve assembly mounted above the air brakes relief valve was popping, however, there is now no upward movement in the suspension at all and no poppping! Full air tank pressure, brakes etc all fine.. NO Suspension movement at all...
 
OP
O

Omfinity

New Member
Joined
Sep 15, 2012
Messages
6
Reaction score
0
Location
Caerphilly
Your Mercedes
Vario 814D 2002
  • Thread Starter
  • Thread starter
  • #4
Mercedes Vario 814d Air suspension fault continued

Update to my investigations:

Made an appointment and plodded along to the official commercial Mercedes agent "Euro Commercials" in Cardiff..

Problem of suspension explained and demonstrated..

Refused request to view under the truck at the same time of inspection..

3 hours later, reported that the fault was not anything to do with Mercedes standard parts, but something to do with an after market modification, which was estimated as possibly a few days work to establish the cause!!

I was then charged £165.00 for the inspection to establish what the fault might be.

I have since contacted the coach builders, Bailey's Body Builders who have assured me that the vehicle chassis and all suspension related parts and controls are indeed ALL Mercedes Standard Factory Fitted options!!

I have also since established that Bailey's Body Builders are correct in stating that Mercedes do indeed supply a manual suspension raising and lower option if request by their customers. Logical really, I cant imagine that anybody would wish to mess around with Mercedes electrics unnecessarily and I am sure that Mercedes certainly wouldn't wish for their systems to be tampered with (perhaps not)

The question I find myself asking is:

If this is standard Mercedes Equipment, why did Euro Commercials not advise me of this fact! The only answer I can reasonably come up with is: Euro Commercial's mechanic was either inept (which he didn't appear to be) or guided to say otherwise to generate further income, or..... Suggestions please!!

The only remedy is to try another Mercedes main agent and see what happens...

I will update again with further information..

Comments appreciated
 

Roxie

Senior Member
Joined
Sep 20, 2011
Messages
814
Reaction score
15
Location
Lincolnshire
Your Mercedes
C Class 350CDI 2012
So what did they think the proplem is? Do you have an air leak from the door control mechanism? Do you have a Kneeling bus?(does the front suspension lower when you open the door)
 
OP
O

Omfinity

New Member
Joined
Sep 15, 2012
Messages
6
Reaction score
0
Location
Caerphilly
Your Mercedes
Vario 814D 2002
  • Thread Starter
  • Thread starter
  • #6
Vario 814d Suspension fault workaround

My apologies for not updating this post earlier..

Many thanks to Roxie for the suggestions and questions.

There were no air leaks from the suspension system.

I visited a couple more MB commercial main agents for an answer to the issue. I was not charged by either, but was not given an answer to the very obvious problem. To me, this made no sense, there was a very clear issue and the suspension sensors on the vehicle, tied into the electronics, must have been reporting errors. The response however was a categoric NOT a MB problem, not even a speculative suggestion that it may be the main suspension control unit or at least related to an electronic sensor.

It was obvious that I would have to seek assistance outside of the main MB network as there was a stonewall. Eventually I came across Avonmouth Auto Electrics who were extremely helpful, had access to the current MB Star Diagnostic equipment and software and had access to a friendly, current MB Commercial Techie, prepared to provide a second opinion.

The problem was very quickly identified, 30 minutes! The main suspension control unit was faulty, which off the record, was confirmed by several sources as being a common known fault by MB!

Due to the vehicle’s new use, a motorhome, a suitable and efficient workaround was possible, at a fraction of the cost that MB would have charged. I am now fully convinced that had Euro Commercials had the vehicle in for full investigation of the possible faults, intimated as being caused by the coach builders, Baileys, I would have had a new suspension control unit fitted and been charged a very fancy price for a known MB issue.

The workaround was only possible as the vehicle was going to remain at a reasonably constant weight, not carrying goods or having weight variation to such a degree whereby constant pressure adjustment was necessary of the air suspension to compensate for weight fluctuations.

The fix.

To adjust the rear suspension ride height, there are two, NS & OS MB electronic ride leveller units, these are normally controlled by the main suspension control unit. These ride leveller units were simply replaced by two manually adjustable ride leveller units, which bolted straight on to where the stock items came off. The suspension ride height was then manually set to the best ride position according to the weight of the vehicle. Problem in part, solved for a fraction of the MB cost.

During this exercise it was noticed that there was very little rear suspension travel, even at full inflation of the air suspension bags, before the axle stops hit the chassis stops, Any suggestions???
 

Comand Online Ltd is a specialist supplier of Mercedes Navigation Disks, Phone & Bluetooth, iPod, DAB, CD and other COMAND retrofit parts to enhance your vehicle.www.comandonline.co.uk
Top Bottom