What does "shock absorber has light misting of oil&quot

[oldcardriver]

Toyota Corolla, 1.3 L, 1998, 120,000 miles.

It passed the MOT, but had an advisory note "rear shock absorber has light misting of oil" for both shockers. I have had a look and cannot see any oil, what does the advisory note mean? The shockers bounce one and a half times when a rear corner of the car is pushed right down. They cost £200 each so I only want to change them if absolutely necessary, and they are not so easy to change as rear shockers used to be years ago

 

[Burnerman]

It means that the tester has seen a slight weep of oil coming from one of the shock absorber seals, but it's not enough to warrant a failure.
Your shocks are working at this time, but if the oil disappears there won't be any damping available.
It's probably wise to budget a change before the next mot.
John

 

[DeletedUser]

Have a browse yourself. http://www.motinfo.gov.uk/htdocs/

 

[Burnerman]

These have turreted McPherson struts on the back, don't they?
Not a 10 min change, but not so bad.
John

 

[oldcardriver]

These have turreted McPherson struts on the back, don't they?
Not a 10 min change, but not so bad.
John

Thanks Burnerman, now you say that, they do look like McPherson struts. As I cannot see any trace of the oil, does the "light misting of oil' occur when the shockers are depressed over the full travel? How on earth they can see it I do not know, because the top half of the shocker is covered by a rubber boot (albeit damaged) and all contained up in the body.

The problem was reported on one shocker last year, and this year it is reported on both, so looks like I should change them soon. They are a pain to change as the spring will need compressing and, the brake pipe is connected to them so will have to be bleed In the old days it was just a matter of undoing two bolts!

 

[Burnerman]

Any oil misting can be wiped away from the shock body, so maybe it's been wiped clean......or maybe there's a bit of drumming up business here!
At the moment, shocks are just checked for leaks, really but the time will come where the car is placed on shaking plates where faults become easier to spot.
As you seem perfectly aware on how to detect worn shocks I wouldn't personally rush to the repair......they do seem bloomin' expensive though!
John

 

[Avocet]

Are those prices for "genuine" ones? If so, plenty of places are likely to sell significantly cheaper aftermarket items.

As Burnerman says, the misting is just "present"(not just when they're moving in one direction or the other). It will be the start of the oil leaking past the piston seals. If you pull up the (remains of) the rubber boot, and look at where the piston emerges from the body of the damper, that's where the oil is likely to be coming from.

 

[oldcardriver]

Thanks guys.

Are those prices for "genuine" ones? If so, plenty of places are likely to sell significantly cheaper aftermarket items.

As Burnerman says, the misting is just "present"(not just when they're moving in one direction or the other). It will be the start of the oil leaking past the piston seals. If you pull up the (remains of) the rubber boot, and look at where the piston emerges from the body of the damper, that's where the oil is likely to be coming from.

Yes, the £200 price tag is for Toyota parts. I looked at Monroe shockers and they are a third of the price but they show 4 different part nos for each rear shocker. The Corolla model changed a couple of months before I bought the car when new, so it will be difficult to ensure that I order the correct part. When I order from Toyota I have to quote the reg no. Koni talk about cutting the bottom off the shockers and replacing the innards, that sounds a bit too dodgy to me.

As I indicated the whole of the top half of the rear shockers are contained up in the body and are inaccessible, even getting a mirror on a stick up there would probably be impossible. However from what I can see it is all dry! I think I just have to keep a regular check on the bounce of the shockers/body.

Edit:-
I would add that the MOT people lifted up the interior trim panel to get at the 3 nuts in the top of the shockers, but they are all that you can see, you can't see below unless maybe you undo the bolts and I find it difficult to believe that they go that far.

 

[Avocet]

As has already been said, I guess it's perfectly possible that the garage was just trying to drum up a bit of work? Lots of online car places have their parts catalogues linked to the DVLA database these days, so I'm sure you'll be able to search by registration number online and get a better deal. Koni have an excellent reputation, so I'd be surprised if anything with their name on it would be dodgy. Certainly, if it were my car, I'd do nothing other than what you're already doing - just monitor the situation.

 

[mfarrow]

A fluid leakage serious enough to indicate that the fluid seal of a shock absorber has failed.

I had mine as advisory for 2 years before failing, and once you have most cars on jacks to be honest they all weep it's just hidden by the dust covers!