So apparently, Porsche doesn't like to sell the entire air spring/strut assembly anymore. They will now sell you the air-spring, the strut, the o-rings, seals, bellows etc - all individually!

Anyway, I now have the left and right air springs and I am lots poorer. You'd think for that money, they'd include the bellows, but that's a big no. No o-rings either. Anyway, does anyone know the top nut torque? I've read 41 ft-lbs. True?

 

M12 x 1.5 supporting mount to piston rod 55 Nm or 41 ft-lbs. Seems correct.

 

Thanks. I spent a few hours really digging in to the new air springs and I have a theory about the leaks that we all have - or will be - dealing with. My suspicion is that it's not the springs themselves that leak. That top rubber pad around the strut nut is there to isolate the vibrations of the actual strut from the airbag. That rubber is about 1" thick and wraps around a 2." metal collar that the top of the strut slides into and seals against. There is a small o-ring inside the collar at the top and THAT is what seals the air on the top. There is another o-ring on the bottom of the bag-mount and that sits on the lower part of the strut and seals it down there. Porsche even lists both o-rings as "seals" in the parts catalog. They're about $10 each.

I would wager a guess that replacing the o-rings on the front struts would fix the vast majority of leaks. I bought two sets and I will test my theory once they all get to the dealer and I pick them up.

For future reference, here is a list of the parts required (and dealer prices) when replacing just the air-spring, since Porsche does not sell the complete strut/airspring any longer:

2 - 970-343-601-00 BELLOWS 33.33
2 - 970-343-603-00 HOSE CLAMP 11.85
2 - 970-343-605-00 O-RING SEAL 13.99
2 - 970-343-607-00 O-RING SEAL 15.82
2 - 999-084-128-01 HEXAGON NUT 1.78
6 - 900-380-008-01 HEXAGON NUT 2.81
2 - 999-074-150-01 HEX HEAD BOLT 6.69
2 - 999-084-445-01 LOCK NUT 2.81

 

good info, looking forward to your findings.

 

Interesting. Thanks for sharing!

I felt ours failed due to leaving the right front suspended for two days as I had the wheel refinished at Wheels America. That was July, and fast forward to October that specific strut failed. PASM was disabled by pushing the level button for 10 secs. If ever I need to lift it again as soon as possible I will support the arm with a jack or similar.

Are you going to try to fill with nitrogen?

 

Not going to fill with nitrogen initially. I may later down the road.

My bags failed after it was left in the air for 4 days by a tire-shop. This also kind of supports my theory on it being the seals and not the bags that fail. Looking at the air-spring itself, the rubber "bag" is only a very small part of the air-chamber. The bulk of it is actually machined aluminum. The chances of the air chamber popping a leak? Just about nill. The rubber for the bag is thick, suspension-grade rubber and while I am sure it can crack and leak if over extended, the travel of the strut plunger would probably top-out before that happens. The way I see it, there are 4 failure points of the air springs:
1. Top strut seal
2. Bottom strut seal
3. Rubber bag
4. Inflation bushing/housing

Leaving the car hanging caused the weight of the assembly to pull down against the top and bottom seal. This either slightly un-seated the o-ring or somehow otherwise caused the o-ring to stop sealing completely. They're rubber, they get stiff over time. That's my theory anyway... We shall see.

 

Do you have the Syntheso Glep 1 grease for the sealing rings? (Saw this in the instruction I have)...

 

Its the same as dielectric grease. I have a bunch

 

Thank very much. This would be an amazing contribution to one of the most irritating, and expensive, faults of the Panamera.