Burn marks on Bilstein shock?
Thread Starter
Pro
Joined: Mar 2003
Posts: 708
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From: New Franklin, OH
Burn marks on Bilstein shock?
Hi guys,
I have Bilstein Sport shocks on my 2009 Z51 coupe. The shocks have 47k miles on them. Today while cleaning I noticed black (burn) marks on the dust booth on the driver-side. When I took the booth off, I saw that the rubber bumper underneath it is completely torn. Passenger side is OK. Both shocks seem to extend the same when I push them in by hand, so it does not appear to be blown.
Anybody ever seen this? Any idea what could have caused it? I've sent an email to Bilstein too, to see what they say...
Thanks! Sonny
I have Bilstein Sport shocks on my 2009 Z51 coupe. The shocks have 47k miles on them. Today while cleaning I noticed black (burn) marks on the dust booth on the driver-side. When I took the booth off, I saw that the rubber bumper underneath it is completely torn. Passenger side is OK. Both shocks seem to extend the same when I push them in by hand, so it does not appear to be blown.
Anybody ever seen this? Any idea what could have caused it? I've sent an email to Bilstein too, to see what they say...
Thanks! Sonny
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 462
From: Southern Utah
That's not a burn mark or it would have melted the plastic boot. Don't worry about it. Replace the rubber bumpers and enjoy them. Bilsteins go for much longer than 47K. They are great shocks.
Thread Starter
Pro
Joined: Mar 2003
Posts: 708
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From: New Franklin, OH
That's the weird part, it is not "on" the boot, I tried cleaning it off with alcohol and such... it is the boot itself that discoloured. And only on the outside, I looked inside with a flashlight and it looks fine. Only damage I see is the rubber bumper that's broken.
I'm just gonna go with the suggestion above and replace the bumper and call it a day... They are really easy to get in/out, so in case something happens down the road, it's easy enough to replace...
Sonny
I'm just gonna go with the suggestion above and replace the bumper and call it a day... They are really easy to get in/out, so in case something happens down the road, it's easy enough to replace...
Sonny
Thread Starter
Pro
Joined: Mar 2003
Posts: 708
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From: New Franklin, OH
Well, just got a reply from Bilstein:
they figured that the bumper got trashed when the shock bottomed out (makes sense) and now the shock might be overheating causing the marks...
Anyway, they offered to send me 2 new boots and bumpers free-of-charge I'm just gonna put those on and see next spring if the problem re-occurs... 
Sonny
they figured that the bumper got trashed when the shock bottomed out (makes sense) and now the shock might be overheating causing the marks...
Anyway, they offered to send me 2 new boots and bumpers free-of-charge
I'm just gonna put those on and see next spring if the problem re-occurs... Sonny
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St. Jude Donor '13
I've seen darker colors "migrate" through lighter color plastic. Is it possible that when the black rubber bumper came apart, some of the black has slowly impregnated the blue dust cover?
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Well, just got a reply from Bilstein:
they figured that the bumper got trashed when the shock bottomed out (makes sense) and now the shock might be overheating causing the marks...
Anyway, they offered to send me 2 new boots and bumpers free-of-charge I'm just gonna put those on and see next spring if the problem re-occurs...
Sonny
they figured that the bumper got trashed when the shock bottomed out (makes sense) and now the shock might be overheating causing the marks...
Anyway, they offered to send me 2 new boots and bumpers free-of-charge
I'm just gonna put those on and see next spring if the problem re-occurs... Sonny
Burning Brakes
Joined: Jun 2013
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From: SW Ohio
Well, if it's not a burn mark (and it doesn't look like one) and it's not black paint (it does look a lot like paint) then my guess is that it's discoloration from either tire rubber or brake dust being directed against the shock boot by tire rotation.