Sealing PSE Pump - SL500

[rexemper]

Hi

I've read in a number of posts about how people have added some kind of sealing to the PSE pump in the boot of their SL, but I don't think I've come across any images of what it looks like; what has worked and what hasn't; what to watch out for etc.

So I thought I'd start a thread to see if we could get something in place that describes what to do - a step-by-step if you like.

I'll start with a picture of the pump in the boot of my SL:

So what have you tried and what works etc? Be really interested to hear about different materials people have used - I've always thought that some kind of vapour membrane (like they use on roofs) would be a good idea as it will let the moisture out but not in.

It would also be useful to know what is under or behind the various pieces of foam, other than the pump which sits on top and is covered by a piece of removal foam.

 

[wizzman]

The foam encapsulates the pse module which has printed circuit boards which do not like moisture. The foam sits on the boot floor so even a shallow pool of water is quickly soaked up. Gradually this moisture will wreck the pse unit. I removed my unit and removed the foam and dried it thoroughly. Before remounting l cut a piece of plywood 12 or 15 mm thick and mount the pse on top which stops the foam coming into contact with any minor leak and l have had no problems. Alternatively sort out the boot leaks in your car.........you will find plenty of advice on that one !!
Crack on

 

[rexemper]

Thanks.

I’ve already had a go at re-sealing the boot seals but obviously still have a problem. Not sure if it’s the boot or something else as some of the carpets inside are wet too.

Is there a step by step or guide on how to remove things before drying out and refitting?
Do you have a picture of the finished job by any chance?
Like the idea of a piece of plywood underneath. I have plenty of that in the garage.

 

[wizzman]

I think it’s all four nuts removed and that allows you to manoeuvre the whole assembly up without disconnecting anything. The foam support comes off as top half and bottom half I seem to recall. Then you will see the space where you need to place the packing wood or whatever material you use that doesn’t absorb moisture. I was going to fabricate some stud extensions so l could bolt it back down but it really can’t go anywhere so l never got round to it. It’s never been a problem again but I did address the boot leaks. Usually it’s the main seal along the bottom of the rear screen. Remove the rubber and clean the metal flange until perfect and then paint with self etch or POR15. Clean all old sealer off the rubber and refit the seal with good silicone or even better, use Sikaflex PU sealer and don’t forget to key the painted flange with rubbing down paper so the sealer grips to it permanently. Take your time and do it inside if possible. Do it properly once or it will fail again.

cheers

Ian

 

[00slk]

Thanks.

I’ve already had a go at re-sealing the boot seals but obviously still have a problem. Not sure if it’s the boot or something else as some of the carpets inside are wet too.

Is there a step by step or guide on how to remove things before drying out and refitting?
Do you have a picture of the finished job by any chance?
Like the idea of a piece of plywood underneath. I have plenty of that in the garage.

It's not only the main rubber seal at the bottom of the rear screen, water can leak in via the C pillars. The tape that sticks these 1/4 rubbers lose there stick after awhile and let water in, which drips into the interior behind the seats and water will also find it's way into the boot. It's a bit involved to remove the seal and to restick it. I'm sure there is a how to do on you tube but haven't a link sorry.

 

[John77]

Don't know if this is the same or helps, but I had the same problem with the PSE pump on my wife's 1999 Slk and things started working. Television was kind enough to let me post him the pump and he rewired and renewed any breaks in the circuit board. He also extended the wires so that the pump could be turned upside down so it did not sit in water anymore. He said this is caused by a poor fitting boot lid and as above, the foam around it soaks up the water and ruins the circuit board.

 

[flowrider]

I would rather fix the leak so that no water gets into the boot otherwise the carpets will eventually rot and the boot will rust.

 

[rexemper]

I would rather fix the leak so that no water gets into the boot otherwise the carpets will eventually rot and the boot will rust.

Completely agree with that. However, sealing or doing something to the pump is an extra precaution in case water gets in regardless of a fix.
Just an extra precaution.

 

[rexemper]

T

It's not only the main rubber seal at the bottom of the rear screen, water can leak in via the C pillars. The tape that sticks these 1/4 rubbers lose there stick after awhile and let water in, which drips into the interior behind the seats and water will also find it's way into the boot. It's a bit involved to remove the seal and to restick it. I'm sure there is a how to do on you tube but haven't a link sorry.

Thanks. Have you seen my other post re the carpets behind the drivers seat being wet?

 

[00slk]

T


Thanks. Have you seen my other post re the carpets behind the drivers seat being wet?

No ..............

 

[rexemper]

No ..............

Ah, I thought you had as I’ve been trying to work out what could have caused the carpet to get very wet behind the drivers seat.

 

[rexemper]

Ah, I thought you had as I’ve been trying to work out what could have caused the carpet to get very wet behind the drivers seat.

@00slk - thread is here - https://forums.mercedesclub.org.uk/index.php?threads/wet-carpets-in-rear-of-sl500.186468/ in case you have any ideas as to where the water could be getting in.