Loud knock when lowering electric roof

[EddySPalm]

Hi,
I am actually the owner lf a 2006 MB Viano Marco Polo, but I can't find a single forum thread discussing roof/camper related issues. I have seen somewhere though, that the electric roof is supposed to be the same as on the T5, which led me here, and I really hope you let me stay for a little while.

I just bought my camper used, with only 100k kms on the clock.

When lowering the roof, the moment I push the "down" button there is a loud knock coming from somewhere.,and then the roof starts lowering like it should. I haven't been able to locate exactly where the knock comes from, but it sure doesn't sound good!

Has anyone here experienced the same? Any idea what it might be? Oh and if you were to buy roof related parts for your campers, where would you go, simply to your local vw dealer?

Thanks,
Edward

 

[Meoncoast]

can not say I recall such an issue being discussed here although there has been a lot of talk about the MP

 

[WelshGas]

Don't worry. I'm sure everyone will do their best to help and might even be asking you a few questions about your vehicle.
Right, not being totally familiar with your vehicle.
The VW has an Electro-Hydraulic system. An electric pump pressurises a hydraulic system and hydraulic ram which pushes the roof up. Pressure is reduced and fluid pumped out to lower the roof.
If there is a clunk or knock when you start lowering I would suggest checking all the connection points/hinges, both Top and Bottom of all the struts. It sounds as if one of these points/hinges could be worn or loose.
Spare parts would normally be sourced directly from a VW Commercial Dealer.

 

[sidepod]

Agreed. It does sound as if something in the hinge/runner mechanism is sticking on activation.

Suggest a good old clean and blast with WD40 before investing further.

 

[Hotel California]

Welcome Eddy , as said above check things visual....one operating the button one standing on a ladder next to the Cali....ooeps....Marco Polo....

 

[sidepod]

Calipolo or Marcofornia?

Got potential. Best bits of each.

 

[EddySPalm]

Wow, I just went to bed after posting my first ever message, and woke up to friggin' 5 replies :O
Thanks all for the warm welcome.

OK so first thing to do is definitely to lower the roof with a helper or two spotting the mechanisms. I guess if I have one guy on each side then at least we can find out which side it comes from and then start to investigate what it is. The whole lifting mechanism seems very much like yours' but with some sort of metal guide on each side to help the canvas fold in by itself. I am actually missing one of these, but MB dealer quoted to £600 for it and it also had to be produced in Germany before eventually I can get my hands on it. I'm hoping this is not the cause of the knock!

 

[GrannyJen]

Eddy, welcome and I am pleased you have had some constructive replies.

I will be really interested in hearing how you have gone on and about your experiences with the MP so please pull up a chair, settle in comfortably and a big warm welcome to a community of fellow campers!

 

[sidepod]

U vill tell uss everysing u know.....

 

[EddySPalm]

Oh my, I feel so warm already!!

I had a look at the roof with a colleague today, and we definitely found out where the knock is coming from. There is a latch on/under the main mechanism that seems to mechanically secure the roof in its top position. The knock is the sound of the latch being "torn" out of position. It looks like it is designed in a way that it should start working its way out of "latching position" when you start lowering the roof, but I don't fully understand it. I'll post a picture soon

 

[WelshGas]

Oh my, I feel so warm already!!

I had a look at the roof with a colleague today, and we definitely found out where the knock is coming from. There is a latch on/under the main mechanism that seems to mechanically secure the roof in its top position. The knock is the sound of the latch being "torn" out of position. It looks like it is designed in a way that it should start working its way out of "latching position" when you start lowering the roof, but I don't fully understand it. I'll post a picture soon

Pictures useful. Might just need cleaning and some lubrication. Could you also post a picture of the missing £600 part?

 

[EddySPalm]

Uhhm, where do I edit my post? Gonna try again with a new one for now... Think you have to click the URL's though.

https://www.dropbox.com/s/kcvqfqe5t8dnpf5/2017-02-03 16.26.54.jpg?dl=0

https://www.dropbox.com/s/h8h9hirevl12bp7/2017-02-03 16.27.03.jpg?dl=0

https://www.dropbox.com/s/ksjqt0yp9kkjed2/2017-02-03 16.27.13.jpg?dl=0

https://www.dropbox.com/s/oo1wndfpo5joea1/2017-02-03 16.27.39.jpg?dl=0

https://www.dropbox.com/s/4iybsofg7v18qni/2017-02-03 16.27.47.jpg?dl=0

https://www.dropbox.com/s/hhacfqdsx3fcpbr/2017-02-03 16.38.03.jpg?dl=0

 

[EddySPalm]

The 600£ part is the curved piece of ABS/PC in the fourth picture, haha. It is definitely not the lack of one of those that makes my roof knock... I'll make one up myself. The reason for the high price was that it couldn't be sold separately.
So what do you guys think? I will try and lubricate it tomorrow, and then maybe/hopefully find out that one of the links in the latch mechanism is stuck.

 

[WelshGas]

The 600£ part is the curved piece of ABS/PC in the fourth picture, haha. It is definitely not the lack of one of those that makes my roof knock... I'll make one up myself. The reason for the high price was that it couldn't be sold separately.
So what do you guys think? I will try and lubricate it tomorrow, and then maybe/hopefully find out that one of the links in the latch mechanism is stuck.

Very different looking system to that used on the California. In picture 3 looks like metal filings underneath the catch as if it is not moving freely and wearing.

I think, could be wrong, that you have to be a VIP member to be able to edit or Delete posts.

 

[EddySPalm]

Did a little more investigating today.
I detached the gas struts and kept the latches in "open" position. The knock went away, hooray. All linkages move nice and freely though, and when I reattached the strut the knock came back.

So do you guys not have any sort of mechanical lock to keep the roof from coming down on its own? I am tempted to keep the gas struts detached, as I fear the big forces that are keeping the roof from coming down will eventually make the hydraulic cylinders leak.

In case I haven't been clear enough; the mechanical latch that seems to be there to secure the roof in its top position is probably designed in a way that it should unlock when one starts to lower the roof. But what happens in my case is that it doesn't.. So the force from the hydraulic cylinders kind of rips the latch out of its locked position, creating a horrible sound (and yes, metal shavings, as seen in one of the pictures).
I couldn't see any sort of adjustment on the mechanism either.

One can see that the latch has sort of an extra "feature" that I think is there to start the levering action of the latch when one starts lowering the roof, but I can't see that it works (obiously) and what's funny is that I can't see how that simple feature could distinguish between a roof that is falling because of broken cylinders, and a roof that is simply lowered in a normal manner...

 

[WelshGas]

Did a little more investigating today.
I detached the gas struts and kept the latches in "open" position. The knock went away, hooray. All linkages move nice and freely though, and when I reattached the strut the knock came back.

So do you guys not have any sort of mechanical lock to keep the roof from coming down on its own? I am tempted to keep the gas struts detached, as I fear the big forces that are keeping the roof from coming down will eventually make the hydraulic cylinders leak.

In case I haven't been clear enough; the mechanical latch that seems to be there to secure the roof in its top position is probably designed in a way that it should unlock when one starts to lower the roof. But what happens in my case is that it doesn't.. So the force from the hydraulic cylinders kind of rips the latch out of its locked position, creating a horrible sound (and yes, metal shavings, as seen in one of the pictures).
I couldn't see any sort of adjustment on the mechanism either.

One can see that the latch has sort of an extra "feature" that I think is there to start the levering action of the latch when one starts lowering the roof, but I can't see that it works (obiously) and what's funny is that I can't see how that simple feature could distinguish between a roof that is falling because of broken cylinders, and a roof that is simply lowered in a normal manner...

No latch to keep the roof up. The system is kept pressurised. Every so often the pump will spin up to re-pressurise the system. About every 72hrs after Ignition Off.

 

[EddySPalm]

No latch to keep the roof up. The system is kept pressurised. Every so often the pump will spin up to re-pressurise the system. About every 72hrs after Ignition Off.

That really makes me wanna just disconnect them, until maybe one day I will investigate the matter more thoroughly.
Actually, if I want to I can just leave the gas struts disconnected, and if I stop somewhere to actually sleep up top I can just reattach them for the stay, and then detach them again before I lower the roof.

 

[BikerGran]

That really makes me wanna just disconnect them, until maybe one day I will investigate the matter more thoroughly.
Actually, if I want to I can just leave the gas struts disconnected, and if I stop somewhere to actually sleep up top I can just reattach them for the stay, and then detach them again before I lower the roof.

Don't quite see how that will solve the problem?

 

[briwy]

If you have established it's a faulty gas strut why don't you just get a new one?

 

[EddySPalm]

Ok, seems like I haven't been clear at all..

The gas struts are working just fine, it is the gas strut that makes the latch lock into position. Once locked, there is something that keeps the latch from disengaging when I try to lower the roof.
Disconnecting the gas struts means disconnecting the latch, meaning the security is the same as on cali's (if WelshGas is right that cali's have no mechanical lock for their electric/hydraulic roofs).

So no, I wouldn't be solving the problem, but I would keep the hydraulic cylinders from having to overcome huge forces of a dysfunctional latch every time I lower the roof, possibly leading to faults on the hydraulic system too.

 

[WelshGas]

Ok, seems like I haven't been clear at all..

The gas struts are working just fine, it is the gas strut that makes the latch lock into position. Once locked, there is something that keeps the latch from disengaging when I try to lower the roof.
Disconnecting the gas struts means disconnecting the latch, meaning the security is the same as on cali's (if WelshGas is right that cali's have no mechanical lock for their electric/hydraulic roofs).

So no, I wouldn't be solving the problem, but I would keep the hydraulic cylinders from having to overcome huge forces of a dysfunctional latch every time I lower the roof, possibly leading to faults on the hydraulic system too.

Have you got a picture of the roof up showing the Gas Strut, basically a view of the side?

I'm trying to get my head round why you have Gas Struts as well, if you can disconnect them and the roof stays up.
Maybe the Hydraulic system doesn't remain pressurised and the Gas Strut is in fact holding the roof up.

Are both gas struts equally pressurised? i.e.: same pressure to compress.

 

[WelshGas]

Ok, seems like I haven't been clear at all..

The gas struts are working just fine, it is the gas strut that makes the latch lock into position. Once locked, there is something that keeps the latch from disengaging when I try to lower the roof.
Disconnecting the gas struts means disconnecting the latch, meaning the security is the same as on cali's (if WelshGas is right that cali's have no mechanical lock for their electric/hydraulic roofs).

So no, I wouldn't be solving the problem, but I would keep the hydraulic cylinders from having to overcome huge forces of a dysfunctional latch every time I lower the roof, possibly leading to faults on the hydraulic system too.

Ok, found a picture. What are these " Gas Struts " you are referring to?

 

[EddySPalm]

Yes, the gas strut is showing in the 1st, 3rd, partly 4th and partly 5th photo. It's lying horizontally on the roof.
It is a small gas strut of only 150N, silver in color. It is only there to operate the safety latch, it doesn't have anything to do with holding the roof up.

I took some more photos the other day, which shows the gas struts a little better:
https://www.dropbox.com/s/227xuyfoim3g7xa/2017-02-04 12.26.16.jpg?dl=0
https://www.dropbox.com/s/pr7av4tcqq1p7hp/2017-02-04 12.29.02.jpg?dl=0

 

[EddySPalm]

It seems like they uprated the gas strut on the new V-class, as it is actually showing from the view of the photo. Mine is not that big, as you can tell from the additional photos.

EDIT: Became a VIP member and can edit posts from now on, sorry for spamming!

I must say you guys are super friendly to help me out even when I don't exactly qualify to join your club

 

[WelshGas]

Yes, the gas strut is showing in the 1st, 3rd, partly 4th and partly 5th photo. It's lying horizontally on the roof.
It is a small gas strut of only 150N, silver in color. It is only there to operate the safety latch, it doesn't have anything to do with holding the roof up.

I took some more photos the other day, which shows the gas struts a little better:
https://www.dropbox.com/s/227xuyfoim3g7xa/2017-02-04 12.26.16.jpg?dl=0
https://www.dropbox.com/s/pr7av4tcqq1p7hp/2017-02-04 12.29.02.jpg?dl=0

Right, I get it now. Is there a strut and catch on both sides, or just the one.

If there is just the one, then probably no harm in removing it. The Roof height might slowly drop over time or with Ambient temperature changes.

If there is one each side then probably best to at least re-fix in place when roof is up as the roof could twist if the Hydraulic pressure dropped causing the roof to lower but one side was Locked in the UP position.