I’ll use Subaru as an example. Subaru issued a bulletin stating that some oil seepage on the struts should be considered normal.
At a Subaru service school one time the instructor stated during that school that some oil seepage is to be considered normal and nothing to be concerned about.
However, with the countless number of Subarus I’ve serviced no matter the model or mileage I can probably count on one hand the number of cars I’ve seen with any seepage at all.
Would this mean that 99.99% of bone dry Subarus are the abnormal ones and the .01% are the good ones?
On the flip side I’ve seen a lot of VWs with oil stained struts and VW says that the struts with seepage need to be replaced.
Here’s a cut and paste below from Monroe about the issue.
Visual Test
Along with the road test, be sure to perform a visual test during the inspection.
When the vehicle is in the shop, first check the shocks or struts for leakage. This is indicated by oil outside the units. It’s important to remember that shocks and struts are hydraulic systems; any leakage indicates the possible need for replacement.
I’m of the belief that struts should not leak, but whether I’m right or wrong OK4450’s comments about the worn struts having been extended beyond their normal travel when lifted and that causing your hard ride and noises are, I believe, and excellent possibility. Even an excellent probability. This would not be at all abnormal.
I would give this suggestion a great deal of weight despite any perspectives on leakage. In truth, it’s an excellent possibility even without any leakage.
@the same mountainbike, when the left front strut on one of my cars failed abruptly after being lifted for an oil change neither of the front struts had one iota of oil seepage anywhere.
To make things even more frustrating, those struts only had about 40k miles on them after the original replacement.
To make things even worse, those struts were one of the very few things I bought online from a well known suspension provider.
They had a lifetime guarantee but the shipping both ways to return them was a killer and made it not worthwhile so I just bought another pair locally.
I know Toyota has a TSB that says some seepage (I count that as sweating) is normal. I am not sure if that is just for them to deny warranty work or no. If you ask Monroe (or KYB for that matter), every strut should be changed exp if they have 50K miles on them.
My 2005 Camry has had some seepage since 50K miles and now it is a bit more pronounced at 150K miles. The ride is a bit bouncy which is new, but still not too bad.
Toyota struts are made by KYB if it makes any difference.
“any leakage indicates the possible need for replacement.”
Emphasis on “possible” . . . IMO
If the struts are not bone dry and show some seepage . . . I used the word wet earlier, but let’s not fixate on exact terminology for the moment . . . but the ride is totally fine, and the car doesn’t have high mileage, they may just be fine
If the struts are wet, the ride is clunking, and they’re not able to control the oscillations, and the car has 200k on the original suspension, they’re probably not okay
If your struts have looked wet for years, and you're a supposed mechanic, you're the last person I'd bring my vehicle to.
Everybody has their own level of tolerance for "failure".
Based on how db4690 described it, he would be my PREFERRED choice over someone that won't tolerate anything less than perfect.
I run into those shops on occasion. Anything less than ideal is an urgent matter for them to address NOW. Um, no thanks…
Seepage happens over time/use. At what point it becomes a failure and must be replaced is subjective. I’ve also lived with seepage for many years without it noticeably impacting performance.
There are people who are extremely proactive and replace at first sign of issues. That is not me or most of my friends and acquaintances. Many times an issue like this has been just fine for many years and survived the normal life of the vehicle. It’s definitely a sign that it’s getting worn out and should be monitored but not a critical issue. That is more or less highlighted in the excerpt OK posted above:
any leakage indicates the possible need for replacement.
Notice it says POSSIBLE. Not imminent or critical or immediate or saying someone is less professional because they didn’t treat it with the same urgency as someone else feels is appropriate…