Spin on oil filter adaptor

[Richard Crawley]

Has anybody has any problems with leaks from the oil cooler take off & return unions on spin on oil filter adaptors? I’ve had the bloody thing off  3 times now & t still leaks. After trying to fix it twice with Blue Hylomar, I spoke to the manufacturer & he sent me 2 new Dowty seals. Convinced this would cure it, I waited until the oil change was due, took it off, fitted the new seals & it’s now leaking worse than ever. Trouble is I’ve now had it over 12 months so a warranty return may be a bit difficult, the casting is not cracked & it seems to be letting by the sealing rings so I wondered if anyone else has had this problem.

[grmills]

Not quite sure where yours is leaking from but I had a dribble from the face which the filter cartridge screws up to years ago. Those nice chaps at Enginuity suggested that this face was not Whitworth flat and should be made good (I wasn't too concerned about it) by taking it off and flattening it out. Done by laying some fine emery paper on a piece of perspex (both with a largeish hole to accomodate the central thread-bar) and smoothing down with a circular sanding motion.

 

Does that make sense? I hope so because I can barely remember what I did, let alone describe it..

[Andy Moltu]

Are you certain the leak is coming from the pipe unions?

Sometimes they leak from around the attachment of the take off to the block - some blocks have a deeper groove to accomodate the filter seal - not an issue with the original canister seal but the physical shape of the adaptor prevents the outer rim of the adapter pressing firmly enough to make a seal against the block.

Some kits are supplied with a thinner inner o-ring to allow the adaptor to enter further into the block but on some blocks even this doesn't achieve a good seal & you have to make a thicker seal by using 1&1/2 seals in the groove.

 

The upshot is the adaptor will feel as if it is firmly bolted on yet fail to make a seal. If it's big oil squirts everywhere, a small one & a drip ensues.

[Richard Crawley]

Hi guys

It's not leaking where it screws onto the block face; I have the later, modified filter housing with a sprung loaded inner seal. The leak is definitely coming from the unions where the oil cooler pipes connect to filter housing. I think the problem is that, for some reason, the Dowty seals just don’t want to seal against the aluminum oil filter housing.

 

Perhaps it’s down to **** machining, I don’t know but I just wondered if anyone else has had a problem.

[jonlar]

Hi Richard, you make reference to Dowty seals, are these similar to o-rings and the "male" part a pressure/interference fit into the "female" or is there any threaded parts?

[Richard Crawley]

They look like an ordinary thick, steel washer with a neoprene lip seal attached to the inside (the hole) & it seals when it’s squashed between the fixing & the casing; the metering distributor inlet hose also uses one. I think Dowty is a trade name (a bit like Hoover); there is a generic term for the design (vacuum cleaner!) but I can't remember what it is.

 

I think the problem is down to the quality of the machining on the face of the alloy filter housing but before I go back & challenge the manufacturer (as I am now out of warranty), I was trying to see if anyone else had experienced the same problem or if mine is a ‘one off’.

[jonlar]

Hi Richard, I know it's my general cure-all, but have you tried a smear of grease on them, rather than Hylomar?

[Guest ron]

Richard

What about wrapping the Dowty seal with layers of PTFE tape, the type that plumbers use?

Ron

[Richard Crawley]

Thanks for the input; trouble is the pressure is quiet high & if it’s blowing by the Dowty seal, grease or PTFE tape is unlikely to cure it. As the manufacturer sent me some replacement seals, I have some spares so I may try cutting the neoprene out of the inside & inserting an fatter ‘O’ ring in it’s place.

[MRankin]

Richard,

Those Dowty seals you mention sound much like a sealing washer I have used with a Swagelok type fastener for copper tubing. The key to it sealing is a slight taper (45 degree angle?) on the neck of the fitting right where the neoprene or viton rubber mates with the fitting body and a true flat surface on the casting. Having the correct fitting and true flat surface are critical. If your fitting has a 90 degree angle at the back of the threads to the fitting body, then you may have the incorrect fitting. Just a thought.

You may want to try a properly sized treated pressed paper washer. One of those thick ones like on the coolant drain plug on the block. Good luck!

[cooter]

Hello Richard,I use a product made by Wurth,similar to thread seal but called pipe sealant,you put some on the threads and shouldered portions and you can still separate the joint if you need,it has proved to be useful for such problems for me.It is anaerobic ie just sets where there is no air so excess is easily removed,hope this helps,

   

 Cooter

[Richard Crawley]

Thanks again for the input. I think I am going to have it off again for another look at what’s causing the problem. I will probably have to resort to a mixture of ‘old fashioned’ sealing washers & goo! It's rather niggling though as these things are supposed to provide a high pressure seal without any of this. As I said, I suspect it’s down to the quality of machining on the filter housing.

[marvmul]

I think I am going to have it off again for another look at what’s causing the problem.

I hope you will find the cause. There has to be a visible imperfection somewhere. It's more satisfying to find the cause, rather than get a repair by trial and error without knowing what was wrong.

[geonecro]

I have just had the exact same problem, in the end I found that the sealing washer was fine on the threaded part of the connector, but between the thread and the part you turn with the spanner, there is a depression with no thread, when I tightened my connectors into the filter the sealing washer was trying to seal in this depression, resulting in a leak, I fitted a spacer to make sure the sealing washer was on the threaded part of the connector and all was OK.

[Richard Crawley]

I fitted a spacer to make sure the sealing washer was on the threaded part of the connector and all was OK.

David

Thanks for that; have not yet had time to have it all apart yet again but will take a look at this when I do.

 

To make life just a little more difficult, my brand new stainless exhaust has started to blow slightly from somewhere under the car so I now need to fix that as well! Hopefully it will be no more than a loose clamp.

[Martti Ojanen]

Hello RIchard! I had exactly the same problem when I installed mine. I removed it and tightened the connectors and they did go tighter. No leaks since. Martti

:blues:

[Richard Crawley]

I removed it and tightened the connectors and they did go tighter. No leaks since.

Hi Martti

No such luck for me I'm afraid as my problem seems to be more fundamental. Only thing I have not checked is David's theory which is next on the list.

[david ferry]

Where did the original spin on filter adaptor and oil cooler hose kit come from?

 

Regards

 

David

[Richard Crawley]

David

The filter & oil cooler came as a kit from TRGB but carry the brand name ‘Mocal’. I have no idea if this company actually makes the components or are, again, merely distributors.

 

Apart from this annoying oil leak it works very well & looks pretty good under the bonnet too.

[Guest ron]

Richard

I think Mocal are the No 1 manufacturers of oil cooler radiators in this country, but I don't know if they make the other bits and pieces in the kit, or buy them in.

Ron

[Colin White]

I also have a Mocal filter housing which never leaked unitl the engine was rebuilt recently and the large sealing ring replaced with one bought locally here in Australia for the original filter bowl. This was very slightly thinner than the original and wouldn't seal properly. Moss & Rimmers sell a kit of replacement seals for the Mocal which I ordered, fitted and problem solved. Obviously slightly thicker. According to our local Triumph garage there are tolerances in the original Triumph block machining in terms of depth of the groove compared with the flat machined centre face. This was not important with the original filter housing. I understand the spin on filter housings now sold by most specialists have a modified design to solve this problem.

Hope this helps,

[Richard Crawley]

I understand the spin on filter housings now sold by most specialists have a modified design to solve this problem.

Colin

I have the modified filter housing which has a sprung loaded inner seal to overcome machining differences with the outer ring seal depth; my problem is not with this sealing ring but the ones on the oil cooler take off & return unions.

[Colin White]

My apologies - I should have read the preceeding posts more thoroughly!

Regards.