Arshad:
"Replacing the hydraulic cylenders will cost about $1500 for a pair. Service manual recommends changing the hydraulic tubing, which isn't sold separately, so the entire kit will probably be >$2000. Then, after installing it, you'll have to flush and bleed the hydraulics, which I have personally done on the 997TT...it is a pain and not a one man job.
I'm fairly certain the part numbers fot the cylenders are different for the cab. When bleeding the hydraulics, if you fill the pump, tubing, and cylenders with as much Pentosin as possible, the maximum elevation of the inner cylender is not as high as the cab (even if you go beyond Porsche's specs.)"
Thanks, bbywu! Didn't know he would have to change the hydraulic tubing & refill hydraulic fluid into the circuit as well (thought it was just a straight-replacement of parts).
You're also right - the part numbers for the lift cylinders are indeed different. But was not very clear about your last sentence - do you mean that even if he changes the lift cylinder, he will still not get the required height?
In any case, I'll inform him about your advice and see what he decides.
(I've also sent him an e-mail inviting him to this forum!)
--
"I dream of a better tomorrow, where chickens can cross the road without being questioned about their intent"
If you look at the service manual, there are instructions for replacing the hydraulic system. If you wanted to do just the cylenders, it is possible, but they recommend changing the tubing also. I've personally gone through this hell, and found that if you change the washers, you could get away with just the cylenders...
When I did my own, I modified the instructions. When you disconnect the old cylenders and are ready to mount the new ones, you need to invert the cylender, fill the chamber and have someone hold it upside down to keep the fluid in the chamber. Then, you take the tubing, submerge it under a cup or basin of pentosin, and have someone activate the spoiler up and down. In doing so, the pump flushes and draws until all the bubbles are out of the line. Then you attach the tubing and tighten the screws. As you tighten, someone needs to activate the spoiler, to flush excess pentosin from the line...as this happens, you tighten the bolt to seal the line. You need to do this with each side.
The spoiler activator will continue to supply energy to the pump until the cylender is completely deployed. On the manual, it suggests that you measure I believe a set height "X" mms...I can't remember the exact number. To get that height, you release the bolt ever so slightly to remove excess Pentosin, and lower the spoiler cylender, then you retighten the bolt. Once you have the correct height, you have to match it to the other side.
Even if you allow the pump to push the heigt of the cylender to its maximum position, it will not be as high as the turbo cab.
Hope that helps. It is extremely tedius and painful, as I hope my explaination above suggests .
Ultimately, I decided to go with this: (yes the wing is fixed on a Ruf...I had Ruf remove the inactive spoiler button with a GT3 lower console)