Suspension: 850 rear shock absorbers – rejuvenated

[Cookeh]

Originally Posted by Moose850

Don't understand what the gaiters have to do with it, the shock are not knackered.

I believe Bi-Fuel is trying to state that when the gaiters fail, or when the shocks begin to fail, that they are no longer able to fully pump themselves up.

You have noticed that upon leaving them unloaded for a period of days they have gained additional travel again. This does seem to reinforce the idea that the shocks are failing.

The counter to this is that they havent yet begun to fail again, which is why I imagine you are struggling to see Bi-Fuel's viewpoint.

If the gaiters are in good condition then that will go some way to countering the idea that they are not failing. Though really a reduced range of travel is typically indicative of the beginning of the end with any shock.

As to why they seem to have been revived somewhat, I suppose it is possible if your shocks do not frequently go through an extended range of travel (i.e. if the car is always unloaded etc) then seals etc can stick. Happens a lot with mountain bike shocks, as an example.

[CNGBiFuel]

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I believe Bi-Fuel is trying to state that when the gaiters fail, or when the shocks begin to fail, that they are no longer able to fully pump themselves up.

Not really?

Cookeh? jeeez... You as well, your posts are generally well considered?

Ask yourself, what is the function of the gaiter? Why do Nivomats last so long?
Why do most cheap shox lack gaiters?

A clue: However stubbornly Mr Moose wants to hold on to the fact that they work now, when the dirt gets to those seals they'll leak. T his is inevitable, the shock is finished. There's signs this might already be happening. The seals hold-up now, thus we can rescue it. Those seals will take a certain amount of dirt, then no more. He's likely near, or on the limit now. Left longer, ie he 'pig-heads' this... it won't be me that forces the grey-matter.

I suppose it is possible if your shocks do not frequently go through an extended range of travel (i.e. if the car is always unloaded etc) then seals etc can stick. Happens a lot with mountain bike shocks, as an example.

Entirely possible, a pocket of over-worked fluid (there's several chambers in those things), valve not used to full-range thus not seating, etc etc consider yourself redeemed.

We are left to ask, what could we fit to a shock to stop dirt scoring the seals? Such that next MOT we're not seeing oil dripping down the stanchion, I wonder?

[Cookeh]

Originally Posted by CNGBiFuel

Not really?

I don't wish to cause any issues or create drama. I stated "I believe Bi-Fuel is trying to state that when the gaiters fail, or when the shocks begin to fail, that they are no longer able to fully pump themselves up." You are now saying this at best partially correct, and yet I quote directly:

Originally Posted by CNGBiFuel

Sounds like they're on the way out. Left alone, they will drop, and in good order this takes a day or two. As they get tired (dirt via missing/ torn gaiters causes this) they drop in a matter of minutes.

Originally Posted by CNGBiFuel

Last forever until gaiters perish, then degrade quickly. Change the gaiters immediately, else finding new gets pricey. VERY.

When gaiters are left too long, they no longer pump to height, find £400 each.

I am agreeing entirely with your statements regarding worn gaitors leading to shock failure, and that failing shocks could indicate the symptoms reported by the OP. If I missed the mark by agreeing with you and repeating the same viewpoints then I fear something may have been lost in translation.

I will admit my knowledge of nivomats is far from complete, so it is entirely plausible I have misunderstood something - either in this thread or with prior knowledge!

Originally Posted by CNGBiFuel

Entirely possible, a pocket of over-worked fluid (there's several chambers in those things), valve not used to full-range thus not seating, etc etc consider yourself redeemed.

Most gracious.

[Moose850]

Originally Posted by CNGBiFuel

Well... what can be said? We tried. Where you can't join the dots now, and won't be told, it's a matter of time before you're forced.

I give up.

I have stated that the vehicle endures Norfolks crap back roads every day and has done for at least the last 10 years. The gaiters are fine and I do not dispute that damaged gaiters will eventually lead to trouble.

I also stated that before I had it on the lift for 2 weeks it was fine and the rear sank a little if unused for a few days which is normal. Now, it does not sink after a few days of no use, I have not left it long enough to see just how long it does take but so far 5 days have seen no sink.

I will let you know if they fail within the next 6 months.

[Moose850]

Originally Posted by CNGBiFuel

They're Nivomat, yes? This is normal. Self-levelling, there's a large clue in the name. Pumped-up via suspension movement. Search Nivomat. Last forever until gaiters perish, then degrade quickly. Change the gaiters immediately, else finding new gets pricey. VERY.

When gaiters are left too long, they no longer pump to height, find £400 each.

I mentioned your comment to an ex Volvo mechanic and he said as far as he is aware Volvo do not sell the gaiters separately.

[Paul240480]

Moose, have you a link to the rear bumpers hangers & did yours come with new bolts please?

[rudi dudi]

Originally Posted by Moose850

I mentioned your comment to an ex Volvo mechanic and he said as far as he is aware Volvo do not sell the gaiters separately.

He's wrong..part no 1387105.

[Moose850]

Originally Posted by rudi dudi

He's wrong..part no 1387105.

Just spoken to Volvo. They say that part number is correct for a rear shock gaiter but it is not listed for the 850. Do you know if it actually fits an 850 rear self-levelling shock?

[Moose850]

Originally Posted by Paul240480

Moose, have you a link to the rear bumpers hangers & did yours come with new bolts please?

Paul,

I got genuine brackets as they were (unusually) a good price at £12.80 each + VAT Part #6816114.
They did not come with any bolts. You need 2 short bolt per bracket to bolt to the chassis and 1 long bolt per bracket to bolt the bumper to the brackets. If very rusted like mine they may shear. It is worth taking you time to try and prevent this. If the long one shear that not so bad but the small are into captive nuts 2 of which were tight and the heads rounded off so I welded good bolts to them and the heat from the welding did the trick and them whizzed undone.

The genuine long bolts are £8 each which I considered too expensive. They are about 130mm long and have a large washer fixed in place. Volvo says the short bolts are no longer listed.

I bought the following stainless steel replacement bolts from www.boltbase.com. via Ebay but you can go direct.
#221275756963 - A2 s/steel Flange head bolts M10 x 25mm Pack of 5 (4 required to bolt brackets to chassis rails) £2.70 inc vat.
#220653920654 - M10 stainless flat form C washers 24mm OD Pack of 25 (4 required for above bolts)£2.25 inc vat.
#322352325419 - A2 s/steel hex head fully threaded bolt M10 x 130mm Quantity 2 (the originals were flange head with built on penny washer so I bought the washers below - flange heads as this length seem not so easy to get but it makes no difference at all)
#321225934061 - M10 x 30mm OD A2 s/steel repair washer. Pack of 10 (2 required for above)

Also, one of the small brackets that hold the sides of the bumper where it wraps round toward the rear wheel arch was rusted away. I bought genuine Volvo part #3518077 £4.10 + VAT. A 10mm flange nut holds these, mine were ok but if yours are rusted Volvo would like to charge you £1.15 + VAT each. Needless to say a 10 pence plain nut and washer will suffice.

While you have the brackets off you can shoot some waxoyl straight down the chassis rails and over the brackets and bolts. I made my own captive nut system to fix the inner wheel arch trim to the bumper so each year I just have to undo 6 M5 bolts, two 10mm nuts and the two 130mm M10's and the bumper slides straight off to enable me to inspect and treat if necessary.

If you need any more info send me a PM. I have lots of photos which might help. I always find it nice to see what's what before you start.

I had to do some welding at the same time so I removed to whole of the interior trim from the tailgate to the front seats so it did not get burnt from sparks or contaminated. If you have to do the same I have the procedure written down and photos of how to remove it.

[SteveSarre]

Hi Moose

I have a few Nivomats from early V70s (not 850s) with bad gaiters, so I have asked the local Volvo dealer for a price for 1387105. I believe that they are not expensive.

So it might be worth your while to just go ahead and get one. I imagine that they are stretchy so might work with your 850 Nivos.

If you give me dimensions of your 850 Nivos, I can compare with the dimensions of the early V70 Nivos that I have.

I don't remember, was your car AWD or not?

And thanks for your information about the other work on the bumpers.

Steve