Oil tank plug threads

philgarner

Member
Messages
226
I've had an oil leak from my oil tank plug for a while now. It's kind of a weird design because theres a helicoil-style thread actually inside the tank hole. If previously improved the situation by pulling out the thread (which was damaged) and putting in another I found. This worked for a while but the leak came back.

I pulled out my temporary helicoil and then took off the 'bowl' piece you can see in the photo. I had planned to replace this whole thing as it was a reasonable price on eurospares but it isn't available from the factory. There is a filter in there (100332) which they did supply. Inspecting the bowl piece I could see the threads were damaged. I found on eBay there is a ready supply of kits to repair and tap out 16mm sump holes to 17mm, and they come with 17mm sump plugs. This looked like a good solution. I ordered one of these sets and tapped it out to 17mm - this was very easy so it must've been approximately this size anyway, but it cleaned up the threads.

There's also a seal (125521) you'll need to replace if you do this. Also not available from Eurospares. I ended up ordering multiple different seals from eBay to try and get a match. What you need is a 78mm outside diameter seal which is 3.5mm thick (see pic). To save someone else having to order all these and mess about is my driver to write this dull post! 20230426_214721.jpg
See new sump plug installed. Torqued up well so hopefully this will work.

20230426_214649.jpg
(Old filter shown)

I've just filled it back up with oil so will report back if I've been successful.
 
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conaero

Forum Owner
Messages
34,631
Loving your work well done.

They are a right pain. Just go easy when tightening.

As a rule when opening these, and the later wet sump engines we paint mark them first to act as a guide of how far to go when refitting.
 

Mr S

Member
Messages
821
I did exactly this end of last year, but i got a cap and plug etc from Meridian Modena, as you say, not expensive but wonder why they could get one and you couldnt, stock maybe? Ross at Meridien did say that they were a common replacement item due to over tightening.
The hardest bit was getting the threaded joiner out the old cap, ended up bolting it to a block of wood, and heating it up with a blow torch and using a dremel to slowly cut the cap around it. No going back, but worked out fine in the end. Also made sure the filter in there was nice and clean. No leaks now which is always good.
 

Mr S

Member
Messages
821
There is a Damper place in Wales that have said they would be willing to work with me to develop some springs and dampers that would exceed what KW currently offer, so i need to get on the case with that. They are currently refurbing 2 sets of Nitron dampers for me for a different project