Thread: D2 Rear Air suspenion issue.

Pneumatic or hydraulic valves can operate to their rated pressure but operating them to their rated pressures can result in them not opening as the high pressure on the downstream side may prevent them opening to dump.

Originally Posted by clubagreenie

Pneumatic or hydraulic valves can operate to their rated pressure but operating them to their rated pressures can result in them not opening as the high pressure on the downstream side may prevent them opening to dump.

The ones I have are rated to 1.0mpa and rated to operate to 0.8mpa. Normally the operate fine but once I load up the Disco they struggle. The Wabco valves that still operate the left and right Valves should be seeing the highest pressure, operate fine. Hence I'm trying to find a Wabco Valve block to replace the valves I have.

I have posted in the "Wanted" forum. I was offered a set a couple of months ago the price was a bit high for something many just remove to put coils in.

Happy Days

that alternative which i presented works without any problem with those 0.8MPa(117psi) valves and i dont see why a 117psi valve would not work at 70psi as long as it's solenoid which opens together with the compressor(or pressure feed) so it's not under pressure untill it doesnt get the command from the ECU ... yes, if a tank it's involved that valve which is the first after the tank could struggle to open if the pressure in tank is more than 5 bar(0.5MPa) but that's not very common

70psi is normal for the SLS when the vehicle is empty but I have no idea what the pressure id like when it's fully loaded.

Mine also works perfectly when the vehicle only has the family and a normal amount of luggage in the back but with the roof top tent, full camping gear, 20L water, 20L extra fuel and all else, 2780kg it's boarder line. It failed to exhaust a couple of times and I needed to pull a line off to get it down once then it was fine.

As the Wabco valves are 2 in 1 unit, they will also save space and reduce the connections that could leak. And they are designed top work at the pressures of the SLS.

Happy Days.

i completely agree that the wabco valve block is the best, i've never contested that, the problem is that you can't buy it as spare part by new only if you buy the whole compressor assy... i've just shown one tested alternative... based on what you said we can agree that this alternative is maybe not for such loaded cars as you described...my friend who runs it doesnt even use a roof rack and usually there are max two people in that car(including the driver)