Roof (anti-) sag. Another thread!

[sidepod]

My interpretation of this is that it explicitly points the finger at the valves as being the main cause if sags in pre-New California models (I can’t bear to call them T7s).
I would dearly like to challenge my dealer on this point were it not for the fact they could never replicate a sag when they had my van in their workshop.

Indeed.Maybe I’m giving VeeDub more credit than is required but, the wording doesn’t suggest the “roof moving downwards” is/was an issue?
Cleverly worded?

 

[vbk1975]

Hmmm. We spent 10 days over Christmas last year with the roof up in Austria. Temp range from -5 during the day to -13 at night.
We suffered sag.
I’m not convinced it’s temp related unless it’s internal temperature from the heater.

On our T6 We definitely have suffered from sagging due to high temp and I made shields that resolve it, but that is only one of the ways it sags.

Post in thread 'Potential roof problem'
https://vwcaliforniaclub.com/threads/potential-roof-problem.50357/post-661876

We also suffer from a gradual sagging over 5-6 days, just enough to take the tension out the front corners but nothing more.

We did have a complete failure and the roof would only stay up on one side (the van was 3 years and a few days old… so no warranty) . I was told that debris from when the pipes get cut to length is what can end up in the valve seats and causes the failure.

There is definitely something in the way T6.1 has been changed that appears to make it a lot worse, both occurrence and severity.

 

[sidepod]

An update on post #1. I’ve just released the straps. Zero roof movement.

I’m not saying it’s definitive. Needs more testing.

Early indications look promising.

I know it was suggested to simply re-raise the roof daily but that’s just annoying when it shouldn’t be necessary.

The slightest amount of “downward movement “ allows the canvas to become floppy and just look crappy.
My experience is, having raised the roof fully you can’t re-tension it without first lowering it slightly.

Anyway all of this has been covered. The point of this thread was to find a cheap simple easy workaround.

There really isn’t much we can do if VW’s version of acceptable droop is way in excess of what’s actually acceptable, meaning getting it fixed ain’t gonna happen unless you end up being half squashed by the roof.

If we keep the van and the roof becomes an issue I’ll have the pump out and get it machined to take better valves.

 

[KevH]

An update on post #1. I’ve just released the straps. Zero roof movement.

I’m not saying it’s definitive. Needs more testing.

Early indications look promising.

I know it was suggested to simply re-raise the roof daily but that’s just annoying when it shouldn’t be necessary.

The slightest amount of “downward movement “ allows the canvas to become floppy and just look crappy.
My experience is, having raised the roof fully you can’t re-tension it without first lowering it slightly.

Anyway all of this has been covered. The point of this thread was to find a cheap simple easy workaround.

There really isn’t much we can do if VW’s version of acceptable droop is way in excess of what’s actually acceptable, meaning getting it fixed ain’t gonna happen unless you end up being half squashed by the roof.

If we keep the van and the roof becomes an issue I’ll have the pump out and get it machined to take better valves.

Reading between the lines, your strap appears to have minimised the pressure on the valve, hence no loss once the strap was released. Very promising indeed, thanks for doing this.

I am looking forward to seeing how the strap can be refined to enable a quick on / off action.

 

[sidepod]

Mk2 version. Double the strap length and pass it around twice. Much easier to tension it.

 

[KevH]

Mk2 version. Double the strap length and pass it around twice. Much easier to tension it.

Out of interest do you strap both sides? How long is the strap? How is it fastened? How long does this all take?
Again, thanks for doing this

 

[sidepod]

Covering the Hydraulic rams with a heat reflective/insulating cover to stop the Hydraulic oil heating up, thus increasing the pressure and the excess pressure bleeding off, so that when the temperature drops the Hydraulic pressure drops as does the roof. Depending of course if this is the actual cause of the sag.

Just re-reading the self help document, it quotes working pressures as 180bar pumping and 100 bar when locked off.

There will obvs be a relief valve somewhere with a setting of at least 180bar.

If the system is locked off (roof up) at 100bar I can’t see how a slight increase in ambient could account for 80bar!!

In other words, I don’t think it’s pressure increases that causes the problem, more simply badly designed valves?

 

[Up10]

Our roof sagged. MY 2023 Q4.
Hydraulic pump changed, roof stopped sagging. There is a new supplier to VW for this part. So suggest that there was probably a manufacturing issue originally.
I wish good luck (because that is all we can hope for with VW) to everyone with saggy bellows and hope you can persuade your local workshop to replace the clearly faulty parts.

 

[Fish111111111.]

???? That sounds bizarre.
So are you saying, if you plug something into the dash skt then lower the roof the lights DONT go out at all?

I think we’ve established the 6.1 doesn’t run auto-correct of the roof.

Sorry i have a 6.1 and can 100% confirm it has autocorrect.