A friend has a nicely modded 1999 Volvo V70 T5. His left front Koni recently ate itself. Near as I can figure the strut insert leaked out and filled the housing. Then the fluid in the housing hydraulically popped the top off, bending the housing and letting the cap rattle around on the shaft. The rattle noise was the first indication of a problem. From what I've rad Konis have a lifetime warranty, but only for the original purchaser. While he has many receipts from the previous owners the Koni bill is not among them.
Has anyone else had to deal with anything similar? Is my friend boned or will Koni work with him? Any sympathetic vendors to try? The struts don't look very old, but without a receipt there is no way to tell.
I very much doubt the cap was blown of hydraulically. More likely the gland nut was loose, and eventually it pounded itself apart.
Bent E36 M3 is NEVER covered under warranty.
They'll happily rebuild it if possible, but they'll charge him. He's not the original purchaser and has no warranty coverage.
I know Bilstein only charges $65 to rebuild a shock, I suspect koni charges around the same.
No warranty for your friend.
If you get them re built you will not have a warranty. It is also usually more expensive to have them re build versus getting new ones. (factor in shipping etc.)
Is the car lowered?
Was he running the bump stops that Koni Requires?
I had a long conversation with Lee over at Koni couple years back about this and the absolute necessity for the bump stops. In short if you bottom out a Koni strut you will trash the strut as the valving hits the bottom of the tube and it is game over. The fluid that is under pressure in the strut will leak out and you get a clunking / rattling sound in the strut. This is especially a problem with cars that have been powered as this shortens the amount of upward wheel travel available in the strut. This is why it is very important to have the bump stops installed on the struts to prevent the strut from bottoming out.
Your description of the problem matches what happened to my Koni's that I bottomed out. I am not sure about this but I think this voids the Koni warranty but I don't remember for sure on this one.
Your description of the failure is very similar to what happened to the struts in my 924s when they failed. Did your friend hit any large potholes, curbs, speed bumps, etc lately? I hit a very large pothole and it bottomed out the strut killing it, causing it to leak all over the place. Reading your description I am not sure your assessment of the failure is not correct. The housing that the inserts go into are not sealed to the piston on the Koni insert. There for the release of the fluid that is under pressure in the strut will not cause the retainer on the top of the housing to come off. It sounds like either it was not tightened up properly or was damaged mechanically from a hard hit to the suspension. In either case since it is not sealed it can not be popped off due to the strut leaking. Also, the housing that the strut insert goes into should be partially filled with antifreeze (could tablespoons go in when the strut is inserted). This allows heat that builds up in the strut during normal service to be dissipated through the antifreeze to the outer housing that surrounds it. If this antifreeze is not present I think you could damage the strut by overheating it. But again the cap that screws on the top of the housing that retains the strut insert does not seal the strut in. It retains the strut in the housing only.
I could not find the receipts from when I purchased them in 1994 and as it turns out I did not have the bump stops on the struts. So even if I did have the paperwork on them I think I would have voided the warranty.
If you replace the struts you will have to ask for the bump stops. They did not come with new set of Koni's that I put in my car a couple years back. They come with a lot of them but you have to ask / verify that they are included.
