Leaking PSE Pump Caused MULTIPLE Issues in My 2004 Mercedes SL500 Including Trunk Soft-Close Failure

Another common issue with Mercedes-Benz SL500 R230 cars is a failed or leaking PSE Pump - PSE is short for Pneumatic System Equipment. This is an air pump that creates pressure or vacuum in soft close systems such as the trunk soft close, the door soft close, the powered door locks, the lumbar supports, and more.
When this pump has a leak, you can hear it making an intermittent rubbing sound in the rear, driver's side of the car. Sometimes it will even error out and stop working all together.
Considering just this part costs nearly $1000 to replace, not including labor, I opted to try and find a more cost effective solution.
R230 SL PSE Pump Part #: 2308000048
PSE Pump Rebuilder: Doug at Instrumedix - [phone]

[@ShutterSpeed_auto]

Nice video. I had a similar issue with the rear soft close so i took out the lock actuator and filled in the cracks with JB weld, held up so far. But I also notice a hissing in both drivers and passenger side doors (even though the locks still move up and down). Instead of pulling apart the driver and passenger side doors, i might go into the PSE pump and just adjust the shutoff pressure time-out so that it doesn't constantly run 10-15 seconds each time it has to lock / unlock the doors

[@rollingstocks]

Very interesting. I have certainly heard of the lock actuator in the trunk going out, but mine has held up so far. The hissing definitely sounds like a leak in the pneumatic system. I've never taken the door panel off the R230, but I have heard it's not the easiest one. It sounds like it still works, so you could leave it, but on my car, I would have to fix it so I don't have to hear about it from my wife, haha.

[@PeterMercedesSL550]

Nice car I just bought a 2011 Mercedes SL550 black on black love AMG package

[@rollingstocks]

Very nice, I've heard the later models don't have as many of the same issues as the earlier ones. I think if I owned a 2011, I wouldn't have any KZbin videos to make, haha! Sounds like a very nice car, congratulations on your ownership!

[@breadsmith6645]

Hey boss loving the videos. I have a question how did you come to the conclusion that the pump was bad?

[@rollingstocks]

The initial indicator was that the pump would run for a few seconds after sitting for a few minutes and then stop, presumably to re--pressurize the system after it had leaked some of the air out. Then, the trunk stopped soft-closing, and that's when it became really apparent. I had a mechanic remove the PSE pump and pressure test it and the lines, and that's when he found the very small leak on the pump itself, near one of the solenoid valves.

[@breadsmith6645]

@@rollingstockswhen you would try to soft close the trunk would it make a long hissing noise and then just give up? I think I have the same issue you are having.

[@CJHazard]

@@breadsmith6645 mine was a small, slow leak so it was a little different, but, based on your explanation, it certainly sounds like you have a leak at either your pump or maybe one of the lines. If you pull the trunk stuff out and listen closely for the leak, you may be able to identify the source.

[@sluggosloan]

Where did you have that pump rebuilt? Was it expensive?

[@rollingstocks]

I was referred to a local mechanic that owns his own company, Instrumedix. I've added his contact info (per his permission) to the description of this video in case you ever go to the dark side and need a Mercedes part rebuilt ;-)

[@rollingstocks]

Also, it was not expensive. Less than 1/4 the cost of a new one.

[@sluggosloan]

@@rollingstocks Thank you!

[@djqueenb]

So how did you find the shorted wire or did you pay someone to do that?

[@rollingstocks]

Great question. I tried really hard to fix that myself, and eventually took it into a shop. One of the seasoned mechanics there was able to tear into the footwell of the car and find the broken wire. I don't think I ever would have been able to find that.

[@mikimiki195]

You can repair that pump for next to nothing by replacing rotary little wheel inside the pump

[@rollingstocks]

This is also true, but it will only fix the pump if the rotary wheel is the problem to begin with. Mine was leaking from the plastic case, so it was an unrelated issue.

[@wilbertwilson9387]

Same question , where and how much did it cost to rebuild the pump

[@rollingstocks]

Great question, a local mechanic that owns his own company, Instrumedix I've added his contact info to the video description in case you or anyone else needs their pump rebuilt.

[@CL500MBZ]

Great question but you won't get the answer here

[@MegaRugby2]

part number