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1999 SL280 Tonneau Cover Slow To Raise - Feels Heavy

1926 Views 12 Replies 3 Participants Last post by  macysum
Hello all. I have been been speaking with Klaus at Top Hydraulics and he has asked me to post here.

I have recently purchased a 1999 SL280 with 67000 miles on the clock. The Tonneau Cover is slow to raise. I checked the Hydraulics and there are no leaks whatsoever.

When I raise the Tonneau Cover by hand it feels heavier than my friends 1997 SL320 with 99000 miles. We are considering swapping the Hydraulics over as it seems straightforward.

I have noticed that on one side (USA drivers side) there is a Black Strut. Does this move like a piston or is it solid all the way through?

I have lubed the working parts with WD40 and it felt easier to raise up. I could not try it out with the switch as I think I have drained the battery somewhat as the Red Switch blinks. Battery is on charge so hopefully I can test it tomorrow.

If it does not improve then I'll look at swapping the Hydraulics over but I'd like to know if I need to swap the Black Strut over also?

Thanks in advance,

Anesh.
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Hello all. I have been been speaking with Klaus at Top Hydraulics and he has asked me to post here.

I have recently purchased a 1999 SL280 with 67000 miles on the clock. The Tonneau Cover is slow to raise. I checked the Hydraulics and there are no leaks whatsoever.

When I raise the Tonneau Cover by hand it feels heavier than my friends 1997 SL320 with 99000 miles. We are considering swapping the Hydraulics over as it seems straightforward.

I have noticed that on one side (USA drivers side) there is a Black Strut. Does this move like a piston or is it solid all the way through?

I have lubed the working parts with WD40 and it felt easier to raise up. I could not try it out with the switch as I think I have drained the battery somewhat as the Red Switch blinks. Battery is on charge so hopefully I can test it tomorrow.

If it does not improve then I'll look at swapping the Hydraulics over but I'd like to know if I need to swap the Black Strut over also?

Thanks in advance,

Anesh.
Would just like to add, could it also be the Pump for the roof as this would probably be easier to swap over?
WD 40 is not a good lube, it'll wash out whatever lube remains and make it worse. I don't know what MB recommends but I'd use a light machine oil.

Keep the engine running while operating the soft top, saves the battery and gives you a couple more volts.
Oh dear. Hope I have not made it worse in that case. I am going to leave the car on charge and give it a go at the end of the day.
It'll be fine :grin just re-oil or maybe a dab of some light grease. Someone will come along soon with some recommended lube but if nothing else some 3 in 1 would do the trick.

Where abouts are you?
In Leicester. Are you a Mercedes Specialist Garage?
No just a private owner, I'm in Warwickshire, let me know if you need a hand with anything. I've not used them but Mercworld (Nuneaton) have a good reputation. :grin
Great thanks! The only other issue with the car is the Oil Light is constantly on and the Oil Temperature Gauge does not register. I suspect a faulty sensor.

Am thinking of taking it to Star Motors here in Leicester but have never used them. Haven't seen any bad reviews for them so might be ok.
Update:

Today I went out to the car after having it on trickle charge since Monday. Tried the roof switch and it just flashed so low voltage was not the problem it seems. I then removed the hard top manually. Tried the roof switch and it just flashed. Disconnected the battery for 5 minutes or so and reconnected. The windows went down partially when the doors were opened. I reset the windows and then tried the roof again. It worked! The Tonneau Cover lifted with ease so I think the WD40 worked!

But I think I need to lubricate the moving parts with better stuff so what should I use?

Also after a drive with the roof down I returned home and the SRS light turned on and it comes on now all the time after about 10 seconds after the car is started and won't go out.

Needs to be reset? But why did it happen?
WD40 is good for a few things but lubrication isn't one of them (WD stands for water displacement, it's pretty good at that).

Tri Flow is what I'd use...

Triflow | Superior Lubricant

Just ordered a bottle off eBay. Should I wipe off the WD40 (difficult to do as the Hydraulic is hard to get at) or can I just put it on over it?

By the way. Left battery disconnected overnight and SRS light was still on but went off soon after driving :grin
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