The o-ring on the remote oil filter
adapter is the weak point of the whole system.
I had one leak (not totally fail) because it wasn't large enough in diameter to make a firm seal when the adapter was screwed onto the engine
(Volvo 2003 engine).
I took the adapter to a machine shop and had them change the groove for the o-ring from the small one that was made during the casting process into a machined flat bottom "u" shaped channel to fit the flat o-ring that comes on the standard oil filter
The flat o-ring gives much more contact surface area when the adapter is screwed onto the engine
block and you always can get a spare just by carefully prying a flat o-ring off of a new oil
These flat o-rings are all pretty generic in size and thickness from one brand of filter to the other, but make sure the diameters of the o-ring (od and id) will be in full contact with the mounting surface of your engine block.
Be sure to put a thin film of oil
on the flat o-ring before putting everything together - same for the o-ring on the new oil filter cartridge.
Many of the manufacturers of the remote
/ relocation oil filter kits say "Not to be used on marine
engines". This is because all of the fittings are made from 6061 aluminum
(either cast or machined), which can suffer from corrosion
in the marine environment
. The other worry was that the sulphuric acid in the oil (from the combustion of diesel
fuel) would eat away the aluminum
Well, if you have that much sea water
sloshing around in your engine space to damage your aluminum adapters, you have a lot of problems. If you change your oil often (which is the whole point of the remote filters) will never have a problem with acid. The new low sulfur fuels are much cleaner and I would imagine produce a lot less acid.
I have had a remote oil filter adapter on the Volvo
for over 30-years. I replaced everything once (adapter, hoses, flat o-ring) about 20 years ago as I re-locate the whole assembly and have never had a problem. The same flat o-ring has been in place the entire time (20-years).
I carry some spare Goodyear "push on" hose "just in case" as well as a couple of original "non-adapter" factory Volvo
filters in case I would have to go back to the original design for some reason.
As mentioned there a lot of different manufacturers of oil filters that use the same threads. The filters also come in a couple of different diameters and a lot of different lengths so you will be able to find something that will fit the space available.
You can go the the Fram webpage (other manufacturers have sites too) and find out what micro size the filter element is for their various filters. I spend a rainy afternoon once checking out about a zillion different manufacturers (US and foreign) filters that would fit onto my remote adapter and found that the micro ratings were usually either 10, 15 or 25 - very much like the Racor fuel filter
So if you find a Zapo oil filter sitting on the shelf of the fruits and vegetable aisle in some teeny general store in Way Way Tanango, you can be pretty sure it can be safely be used on your engine as the threads, o-ring and filtration rates are nearly the same world wide.
My engine - now 30-years old - still has the factory recommended oil pressure readings at idle and at speed when at operating temperature (ie - hot), so the hoses and adapters don't really effect the oil pressure - but they are "full flow" 1/2" fittings and hoses so there are no "restrictions" in the oil system.
The remote filter was the best thing I ever did for the Volvo engine!