EAS Fault - running out of ideas!

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groomvroom

New Member
Posts
6
Hi All

I am having trouble locating a problem with my EAS system. Only had the car for three months or so, shortly after buying it, I had a rear bag burst so I replaced the two rears, all OK for a month then I noticed it was taking longer and longer to get to the selected ride height, eventually it wouldn’t rise at all and the pump was running continuously. A bad pump seal was suggested, so stripped the pump and the seal had melted and the barrel was wrecked, replaced both, pump still running continually, it lasted a day and the piston rod in the pump snapped. Bought a reconditioned pump, now reaching all the height settings but the pump still running all the time, fitted air line adapters and pumped up all four bags, not dropping in 48 hours, bought a block seal and diaphragm kit, everything looked in good shape but fitted anyway, pump still running but ride height reached faster, checked all connections for leaks including the dryer, with the silencer removed, after switching off the engine, you get a spurt of air then it continues to vent air slowly for 3 minutes or more, the ride height stays constant. Should this happen? I have a set of front bags to fit but when manually filled they stay up fine, there are no leaks I can detect around the air tank, the pump runs continuously then you get a blast of air vented, it goes off for 3 seconds or so and starts up again. Any help greatly appreciated. Interestingly, I have never had a soft or hard fault.
 
groomvroom said:
Hi All

I am having trouble locating a problem with my EAS system. Only had the car for three months or so, shortly after buying it, I had a rear bag burst so I replaced the two rears, all OK for a month then I noticed it was taking longer and longer to get to the selected ride height, eventually it wouldn’t rise at all and the pump was running continuously. A bad pump seal was suggested, so stripped the pump and the seal had melted and the barrel was wrecked, replaced both, pump still running continually, it lasted a day and the piston rod in the pump snapped. Bought a reconditioned pump, now reaching all the height settings but the pump still running all the time, fitted air line adapters and pumped up all four bags, not dropping in 48 hours, bought a block seal and diaphragm kit, everything looked in good shape but fitted anyway, pump still running but ride height reached faster, checked all connections for leaks including the dryer, with the silencer removed, after switching off the engine, you get a spurt of air then it continues to vent air slowly for 3 minutes or more, the ride height stays constant. Should this happen? I have a set of front bags to fit but when manually filled they stay up fine, there are no leaks I can detect around the air tank, the pump runs continuously then you get a blast of air vented, it goes off for 3 seconds or so and starts up again. Any help greatly appreciated. Interestingly, I have never had a soft or hard fault.
Click to expand...

Change the exhaust diaphragm it is more than likely split. There should be no air coming from exhaust other than the burst as the pump stops and exhaust back pressure to allow pump to restart in free air.
 
wammers said:
Change the exhaust diaphragm it is more than likely split. There should be no air coming from exhaust other than the burst as the pump stops and exhaust back pressure to allow pump to restart in free air.
Click to expand...

Yes already did that in the overhaul, always possible its not seated correctly, just tested the preasure switch and its permantly open which I guess means its not reaching the correct PSI, just check the operation again and if you go from the high setting to the low, it takes too long to go back up unless you open the door and let the tank fill first, then it works as it should, can I loose pressure through the diaphragm? The old one was cracked but not split through.
 
groomvroom said:
Thats the one I used
Click to expand...


Ok then all should be good. Treat the EAS as two seperate systems. Pressure generation and storage side and pressure distribution side. If after inflation your suspension is staying up. No air is being used so the air in the tank should not be getting depleated unless there is a leak. If you have 140 psi in the system the pump should not run. The pump can only run when the pressure switch detects a fall in air prassure below 120 psi. You may have a faulty pressure switch or the small pipe from the tank that feeds the switched could have a restriction. If you have a leak from around the switch housing and there is a restricted airflow through the feed pipe the pressure is lost from the back of the switch causing the pump to start, but because the flow is restricted in the tell tale pipe it does not build pressure to shut the switch until the compressor has run a while. Then the prosses is repeated. Hence constant compressor.
 
wammers said:
Ok then all should be good. Treat the EAS as two seperate systems. Pressure generation and storage side and pressure distribution side. If after inflation your suspension is staying up. No air is being used so the air in the tank should not be getting depleated unless there is a leak. If you have 140 psi in the system the pump should not run. The pump can only run when the pressure switch detects a fall in air prassure below 120 psi. You may have a faulty pressure switch or the small pipe from the tank that feeds the switched could have a restriction. If you have a leak from around the switch housing and there is a restricted airflow through the feed pipe the pressure is lost from the back of the switch causing the pump to start, but because the flow is restricted in the tell tale pipe it does not build pressure to shut the switch until the compressor has run a while. Then the prosses is repeated. Hence constant compressor.
Click to expand...

Sorry Wammers, but I must correct your pressures. Pump cut in is 104 to 116psi (7.8 to 8 bar) Pump cut out is 138 to 152psi (9.5 to 10.5 bar) as specified in RAVE.:D
 
Datatek said:
Sorry Wammers, but I must correct your pressures. Pump cut in is 104 to 116psi (7.8 to 8 bar) Pump cut out is 138 to 152psi (9.5 to 10.5 bar) as specified in RAVE.:D
Click to expand...


Thank you but a rather think 120 to 140 was near enough for descriptive purposes. The point is the pressure switch is either on or off there is no in between. At whatever parameters your personal switch works at it should not switch the pump on again unless the pressure drops below the lower limit. This should not happen within seconds of the pump stopping and evacuating. There is a considerable volume of air within the tank, for the pressure to drop by 20 psi or more in seconds either means a massive leak which is unlikely, or a malfunctioning switch or air leak from the switch chamber and/or slow pressure feed to the switch. The air pressure from the compressor passes an NRV into the tank, that pressure is then confined by that NRV and the inlet valve. The switch is fed by the small pipe back from the tank. The pressure in this small pipe feeds the back of the switch for sensing purposes. The pump cannot run unless the switch is closed circuit. Therefore either the switch is duff and has drasticly lost it's offset, or there is a leak in the switch chamber which is faster than the small feed pipe can supply pressure to keep the switch open circuit and therefore the pump off.
 
wammers said:
Thank you but a rather think 120 to 140 was near enough for descriptive purposes. The point is the pressure switch is either on or off there is no in between. At whatever parameters your personal switch works at it should not switch the pump on again unless the pressure drops below the lower limit. This should not happen within seconds of the pump stopping and evacuating. There is a considerable volume of air within the tank, for the pressure to drop by 20 psi or more in seconds either means a massive leak which is unlikely, or a malfunctioning switch or air leak from the switch chamber and/or slow pressure feed to the switch. The air pressure from the compressor passes an NRV into the tank, that pressure is then confined by that NRV and the inlet valve. The switch is fed by the small pipe back from the tank. The pressure in this small pipe feeds the back of the switch for sensing purposes. The pump cannot run unless the switch is closed circuit. Therefore either the switch is duff and has drasticly lost it's offset, or there is a leak in the switch chamber which is faster than the small feed pipe can supply pressure to keep the switch open circuit and therefore the pump off.
Click to expand...

Outstanding info Wammers:cool::cool:

Thanks for posting this, I often wondered what the small hose was but never thought of it while on RAVE. Thanks:)
 
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