R230 - PSE constantly cycling

[Markmac]

Hi, I purchased a 2004 SL350 approx a month a go with a few faults. The roof would not operate or the boot release. From working through the car I discovered that the PSE pump installed in the car was from an S Class not an SL.

I purchased a second hand pse from eBay. The roof now works as does all the PSE related functions (I have a new boot actuator installed also).

The problem I have is the PSE constantly cycles when the car is unlocked. The glovebox would lock and unlock by itself. I've capped the airline to the glovebox with an end cap but the pump keeps cycling. I've pulled the fuse to stop the pump overheating.

I'm at a loss, do I have a bad PSE pump?

 

[LostKiwi]

Sounds like you have a vacuum leak somewhere.

 

[ajlsl600]

Almost certainly. Find it before it kills ur pump. From memory often under seats?

 

[Markmac]

Thanks, I've order a vacuum tester this morning. Should all lines hold a vacuum or does the lines attached to an actuator release at a set pressure?

 

[LostKiwi]

All should hold vacuum as far as I'm aware.

 

[Markmac]

Vacuum tester arrived this morning. I've tested the lines and found boot, two door lines were not holding a vacuum at all. I found the leak in the boot by the hiss and repaired the pipe with a push to fit joint. The boot line is now holding a vacuum. I assume the door leaks is normally at the actuator. Would this be the case?

To check function of the pump, cut the two lines to the doors and fitted push to fit endcaps (tested holding vacuum). I refitted the fuse to the PSE however it is constantly cycling. I can confirm all other lines are holding vacuum and functioning as they should. Do these PSE pumps require programming? I thought the pump would shut off once pressure/vacuum was achieved. Any suggestions would be greatly appreciated!! Thanks