Hissy seat

[W1Z]

Hi all, I wonder if someone can help...

The close assist on my boot doesn't work (SL500 04). It does the usual thing of working for a while after I pull and replace the fuse under the rear storage compartment, but then failing again. I checked the vacuum to the rear lock and it seemed ok, I even had the lock pump changed (was done under warranty) but that was ok too. Then tonight I heard a hissing from the driver seat and thought maybe I have a leak there. When I looked under the seat, I found a length of rubber pipe (about 18") that was connected to a vertical nipple under the lumbar adjustment control, but un-attached at the other end. I've tried in vain to find where the other end of the pipe should attach but to no avail.

Could anyone give me a clue as to where it should go? And do you think that is the cause of my close assist failing as I believe the two are connected?
Thanks in advance.

 

[television]

Hello and welcome, I did get your PM from benzworld.

The pipe has come off the valve block on the seat backrest.

I am sending you 2 papers, 1 for the back and 1 for the sides on how to remove, you should then see where the pipe has come off the valve block in the center of the back rest.

The seat is driven by the PSE pump in the boot, this is CAN operated and only the valve on the pump is opened when the command is received to open that valve.

Often when there is a leak, the pump can shut down, but yours has not done this so far.
Put the pipe back and we can deal with other faults after that.
If you would like the valve block paper I can print one off but you should not need it

 

[television]

I do need your Email address please

 

[W1Z]

Thanks Malcolm you're a star...

I've pm'd you my email address, thanks again.

 

[television]

Thanks Malcolm you're a star...

I've pm'd you my email address, thanks again.

It has not come through yet

 

[W1Z]

No probs it's:


Just don't want he spam crawlers to pick it up that's all.

Thanks

 

[television]

OK you can go back and in "edit" on your last post delete the address.

I tried via benzworld, but that did not allow me to atteach things.

2 papers sent

 

[W1Z]

Thanks for the pdf's Malcolm. Do you need to remove the seat to perform the side and back removal or can it be done with the seat still in place?

I get the feeling you don't think this pipe has anything to do with the boot close assist failing? Funny thing is, resetting the close assist with the fuse always makes it work again for a while but then it stops (usually over night). Sometimes, after it's stopped working, it does start working again even without removing/replacing the fuse - which is very confusing. Everything else (cental locking etc) seems to work fine.

Looks like I'll have fun getting to the bottom of this one, it's very nice to know someone who knows more about it than the dealers seem to

 

[television]

You can do it all with the seat raised, do not take any pipes off the front panel with backrest lumber adjust.

I do not know anything about the closing assist, but it could use the same air tank in the boot that the seats use, until the seat is fixed we will never know.

I will look up the closing assist and see how it works. I do not have that on my car as it is too early for it.

I never get time these days to post on Benzworld or MB world, but I know there are loads of questions that do not get answered

 

[W1Z]

Well I'm glad you post here mate . I have followed some of your other threads, expecially about the pump problems and they are really helpful. Appreciate it.

 

[W1Z]

Well, I finally got a chance to work on the car today and I think (hope) I’ve fixed the problem. Firstly, a big thanks to Malcolm (Television) for sending me the instructions for removing the panels off the seat so that I could access the pipes.

There seems to be two kinds of vacuum pipe in the seat, the thin, hard plastic type that are most common throughout the car and a fatter more conventional rubber tube. It was one of the rubber tubes that had become disconnected on my car. One end of the tube was attached to the nibble that comes vertically down from under the lumber adjustment wheel, the other end, as it turned out, should have been connected to a nipple right at the front of the seat frame behind the storage bin. It was a bugger to get to, but now I know how, it will be easy if it ever happens again.

I couldn’t find where it should go at first, so in the end I traced the one on the passenger seat. To re-fit this particular pipe, you only need to remove the storage bin, which is held in by four screws and the lock bolt. There is a pipe junction right at the front behind a metal plate bracket, close to the carpet. It is very hard to see and it appears clipped into place by a small plastic clip that is “twist locked” into the metal bracket. The pipe junction box is only pushed into the plastic clip, so it isn’t necessary to remove the clip from the metal bracket to get access (as I did ). You can simply push the pipe junction connector away from the metal bracket and it slides out of the plastic clip, you can then re-connect the rubber pipe and replace it all. To help you locate the pipe junction box – it’s almost touching the carpet and had three nipples on; two for thin plastic vacuum pipes and one for the fatter rubber one.

Sorry I don’t have pictures but I didn’t have a camera to hand when I did the job. If anyone finds this thread and need clarification however, PM me and I’ll gladly elaborate for you.

Anyway, I’ve tested it many, many times now and both the lumbar support and boot lid close assist or soft close work every time. I hope that’s it fixed for good now, thanks again to those who helped.

 

[television]

OK so the closing assist does use the reserve tank in boot.

So pleased its fixed, thank you for your offer, and should you ever need help again you know where to come

 

[W1Z]

OK so the closing assist does use the reserve tank in boot.

Yep, looks like the two are connected on the same circuit; I kinda suspected they were because I'd seen other people on the forums with the boot close-assist failure and it always seemed to be that their lumber support adjustment failed as well, but it's nice to have it confirmed.

I'm new to SL ownership so I don't know much about them at all, but it looks like I'll be finding out how most of it works over the next few years :? . Thanks god for forums like this one

 

[television]

WEhen I first bought my SL the comfort seat were not working so plugged it into STAR at MB they said there was a leak in the drivers seat.

I removed all of the leather seat cover on the back rest, and disconnected from under the control panel on the seat and blew the seat up, it stayed up all week, so I went back to MB and asked to see their STAR guy and they let me into the workshop where we plugged it in and he said still got a leak in the drivers seat, so I asked him to go to the seat menu and look to see if the car know that it had Comfort seats, that was turned off, so he turned them on and all was well.

Since then I have replaced struts and 2 SAMs my last job is that STAR cannot find the Comand on my car and it does not shut sown on a wake up circuit. For now I have made my own shut down that turns it off in ½ an hour.

I have to remove the sills and rear inside trim to scope up the D2b and where this ring joins into the CAN, I will do that soon

 

[W1Z]

Well, damn and blast, the boot close assist has stopped working again :cry:

Funny thing is, the lumbar support is still working, so at least that pipe seems to have solved that problem. I'm really not sure where to go from here, the lock pump has been changed for new so I know that isn't leaking and everything else seems to be working fine, but the boot is a swine to close without the assist working so I'd love to find a way of fixing it.

Ho hum, any ideas welcome ...

 

[television]

See what I can find, This is one thing that I have never looked at

 

[W1Z]

Thanks Malcolm

The weather was pretty good today so I decided to take the afternoon off and really look into this.

I took the air pipe off both ends (pump and lock) and checked it for leaks but it didn't have any. The lock release works fine all the time without any problems (works on the same pipe), but when the close assist is activated, it seems as if the pump is not being told that the operation is complete, even when it is done. This means that the pump runs on until it cuts out on what must be a timer. Two goes like that and the system assumes the close assist isn't working and stops triggering it until the fues is pulled and the pump is reset.

I'm beginning to think that there is something wrong with the sensor in the pump. I missed one recently on eBay, it sold for £100 :cry: but I suppose that is going to be my next purchase.

Ho hum

 

[television]

I have no info on my WIS it is a 06 version so too early, I have a new version but not working yet.

From your description it sounds as though the pump is not being told to run long enough to complete the action. It is CAN controlled, on STAR it must say something about what is going on

 

[W1Z]

Found a great article covering what looks like it may be my problem. It's not specific to my model of pump but the principle looks the same.

http://www.v12uberalles.com/Closing_Assist_Pump.htm

It seems that the pump may be adjustable as to the pressure at which it switches off. That would certainly seem to solve the problem if I can do it.

I'll let you know...

 

[television]

The pressure is not adjustable bur what I said in my last post, maybe the running time is. There is a max setting for the run time, as these pumps soon overheat, the slightest leak in the rams could cause the problems