E Class W211 2007 Self Leveling Suspension

[JohnB50]

Hi Guys, just wanted a bit of advice.
BACKGROUND
I replaced NS rear air Spring last year with a Bilstien OEM one and everything was fine. Did the OSR one last week due to leak and everything seemed fine although it was slow to get back to full pressure in the new spring, however after a week and about 100 miles the new Spring failed. I think looking at it I must have put too much weight on it before it was fully inflated a it pinched or damaged the bag. A costly mistake but fortunately I got a good price from ECP so only wasted £280! While I've got it off the road I'm also reconditioning the compressor and replacing the filter and relay.
QUESTION
I don't have access to Star diagnostics so to avoid making the same mistake I've worked out the following. I can run the compressor by bridging 30 and 87 on the compressor relay then I've played around with the valve on the failed spring and have made a plug so connect it to a small 12v battery which opens the valve. If I fit the new spring, connect the air supply then run the compressor and open the valve I should be able to partially inflate the spring before reconnecting the proper plug, lower the weight on to the spring, reconnect the relay , start the car and let it sort its self out. Can anyone see any problems with this? Will it confuse the ecu by reconnecting the battery and running the compressor by bypassing the relay and opening the valve in the spring with a separate 12v supply?

Sorry for the long post. Thanks John

 

[Dodipops]

Don’t think it would confuse the ecu doing a bypass to run the compressor but can’t you just start the car while on the jack so the full weight isn’t on the new bag, just until it fills it itself?

 

[JohnB50]

That's what I did with the first one and it worked ok, I think what went wrong this times was that the compressor did run as the axle level sensor was in the correct position, not too high or too low so I let more weight down to trigger it to start and probably was impatient and let it down to far. I'm just nervous of damaging another spring now and the instruction with the Spring and in Haynes manual tell you it must be re-inflated using Star.

 

[Dodipops]

Yeah you’re meant to use star or alternative to inflate. What about disconnecting level sensor and moving it manually to start compressor?
If you can get the rod off the a.r.b.

 

[steveq]

Hi,

That all sounds very complicated.

I suggest that, when you are finished the installation of the unit, you refit the wheel, remove any axle stands from under the car so it is just held up on a decent trolley jack (and you're not under it).
Then lower the car slightly so that the wheel is on the ground and the car is roughly at the correct height but all the weight is still on the jack. Then start the car so that the new air suspension unit inflates.
You could then slowly lower the jack so that the unit takes the weight and review it all then.