Yes, Viton. Found local place that can cut them from solid piece of Viton.
Toroidals - as in el.transformers?

Yup, the same, torus is more apt for an O-ring shape, but manufacturers call them torodial seals....

Got some 9x1.8 Viton "O" ring this week to fix my oil leak.
Is it just a case of removing and replacing them? no chance of an air lock in the pipe ?
Thanks Dave

I had no problem and I changed them twice. It is tight place so try not to drop the bolt.(ask me how I know) I use this. It has magnet prest in it.Put some oil or vaseline on.
Pardon my english.

All done, did not take long. One of the old O rings was split. The new 9x1.8mm seamed to be a bit thick in section it was a pig to push the nipple back in to the block had to use the bolt to pull it back in the last few mm.
Bit of a tip, if you don't have a magnetic 8mm socket stuff blue tac in a standard socket and it works a treat 😄
Anyway, just need to keep an eye on it for a few weeks now and check for leaks.
By the way anyone know what the little bar is just under the 8mm bolt? It vibrates like when the engine is running and after engine has stopped for a few mins it moves towards the right about 1.1/5 inches.

After looking at the pictures I think when I do mine I'm going to fit a third larger viton 'O' ring seal. There appears to be a handy looking groove where the fixing flange meets the pipe which seems to be crying out for an 'O' ring. Belt and braces maybe but can anyone see a problem with this?

Just checked mine again.
Still no signs of any leak.
If/when it does leak, I am going to just replace the 2 Orings using Viton rings and then check it every few weeks,
62,000 miles now.

Dogfishdave wrote:

Got some 9x1.8 Viton "O" ring this week to fix my oil leak.
Is it just a case of removing and replacing them? no chance of an air lock in the pipe ?
Thanks Dave

Hi Bish, from the net somewhere but can't think where. I have a few left, pm me your address and I will pop you some in the post.
They are a good fit but takes a bit of pushing to get the nipple back in the housing with the new o rings on. I smeared them with oil first. When put the bolt back, I used some blue tac in the socket to hold the bolt it worked a treat.
Thanks Dave

Very kind of you Dave!

PM sent.  Bish.

2005 110 TD5 CSW
2011 TDV8 Vogue SE (gone)

Just ordered a cheap bag of Viton rings which were 1.78CS x 8.73ID to have in for when it starts leaking. As it has been commented on the 9 x 1.8 seemed tight to fit so by my reckoning losing 0.02mm off the section and 0.27mm off the ID might make them slide in a little easier. These were the closest size I could see on the site I was using. www.simplybearings.co.uk There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
Fiat 500x 1.4 multiair Lounge 2015
2010 LR D4 Commercial 2.7 TDV6

The document 55257_JW_'O'_Rings_Issue_7_2015_-1.pdf provided by James Walker, an O-ring manufacturer, shows the shaft and cylinder dimensions for various o-ring sizes. The 1.78 mm x 8.73 mm is used for a 9 mm dia shaft with a 12 mm dia cylinder. The 1.8 mm x 9 mm is an Aerospace o-ring dimension so less likely to be the correct size than one for a 9/12 mm automotive application.

I too have ordered BS611 (8.73 ID x 1.78 CS) in Viton 75 to have on standby. I'll measure the bottom of groove and bore dia when the time comes and hope to confirm the 9mm/12mm size for the BS611.

My oil cooler recently started leaking, so I booked in to my local indy. They found that a gasket had failed, the big one between the cooler assembly and the block. All seems good, I've applied the Italian tune-up procedure a couple of times, and no leaks... just hope the thing doesn't now crack ! It's a plate/plate heat exchanger as you know, so probably won't give me much warning of its impending demise.
Next thing to do is the serpentine belts and idlers, sounds like a nest of budgies working out on a hamster wheel when started from cold...  The best 4.4 x far

Hi all, I need to get some of these O rings, has anyone been able to get the correct size of 9.00 x 1.80mm online anywhere?

Any help would be a great

Thanks in advance Current: 2015 4.4 SDV8 Autobiography
Old: 2011 4.4 TDV8.... OMG
Old: 2003 TD6 HSE Java Black
Work: 2016 VW T6 140