Purolator - how tight?

[Chief]

Now that I'm physically able to work on my car again (last time was early 2023) I decided to have a go getting the oil filter sorted.

As a reminder, I'm taking my car back to stock so have been re-fitting an original Purolator filter housing in place of the screw-on conversion.

Since it had been so long ago I took everything off the car to check what condition it was in and have since bought the following replacement parts:

Oil feeder pipe (2nd hand from ESM)
Oil filter housing cannister (2nd hand from ESM)
Lower Collar, Collar Seal and inner circlip (all brand new).

Are you meant to turn the bolt until it can turn no more or will there be a point where I over-compress the seal and thus create a leak?

I'm asking as currently I have a slow leak from the collar (takes several minutes to develop a drip) and I've kept tightening the bolt and it's reaching the point where I fear I'm overtightening it. I haven't bothered turning the engine over since the leak is just what oil I'd poured into the cannister before fitting.

On another point, is it normal for the top seal to keep falling out? I think I finally got it to stay while I tightened it up, but it was still a nuisance (and of course I won't know if it's sealed until I turn the engine over).

Thanks

[svenedin]

I thought the spin on modification replaces the top part of the oil filter as well (the bit that bolts to the engine). You don’t mention putting the Purolator top part back?

I have the Purolator and the top seal does not fall out. My filter does not leak and all I do is nip up the bolt until it feels secure. I couldn’t really say what torque that would be but it’s not especially tight.

Stephen

[Chief]

Just to clarify, the parts listed were replacement parts for the Purolator I have, I didn't merge the spin-on top head with the lower Purolator parts

It was less a torque setting (since my torque wrench has given up the ghost anyway) and more a case of how tight is tight - or how secure is secure.

By nip up, does the bolt stop turning or does it become very tough to turn?

I've currently got a drip tray under so I can determine how much I lose over a long period, of course there's always the risk I already lost it all and if it appears to be leak free it'll be because there's none left

[svenedin]

The bolt becomes stiff to turn. I buy my replacement filters from ESM. There are 2x rubber top seals in with the filter. They are not the same and 1 is the wrong size. I think if you do the bolt up too tight you’ll just make it worse. Although I bet you don’t want to do it I’d take it apart again. The seal may not be properly seated. I do the filter by getting the front of the car on ramps and working from underneath. Oil usually drips on my face!

Stephen

[Chief]

If I take it off again that will make it the fourth time of doing so

I used the thicker seal, the one phillthehill mentioned was on his spare Purolator head in the MM oil thread since it seems like being the best fit.

I've also been out again to confirm how much it was losing and I'd say 1/2 a teaspoon in 20 or so minutes. I decided since that was less than it had been I'd give it another tighten and it's definitely now very tight (I pulled a chest muscle, so I definitely wouldn't risk tightening it further ! ).

No ramps etc. in my case, just me on the floor worming under the car with all four wheels on the ground (it's not so bad if you go in under the number plate).

[simmitc]

By "collar", do you mean around the bolt at the bottom or round the top lip of the cannister?

The sealing ring on the underside of the head usually stays in place if pushed firmly into the groove in the head - a blunt rod helps; but a couple of dabs of grease can help hold the seal in place whilst you lift the housing - rotate the housing gently (just a little bit) to help seat against the seal. At the bottom of the bolt there should be a seal on the outside of the housing to stop any leak.

[svenedin]

If I take it off again that will make it the fourth time of doing so

I used the thicker seal, the one phillthehill mentioned was on his spare Purolator head in the MM oil thread since it seems like being the best fit.

I've also been out again to confirm how much it was losing and I'd say 1/2 a teaspoon in 20 or so minutes. I decided since that was less than it had been I'd give it another tighten and it's definitely now very tight (I pulled a chest muscle, so I definitely wouldn't risk tightening it further ! ).

No ramps etc. in my case, just me on the floor worming under the car with all four wheels on the ground (it's not so bad if you go in under the number plate).

I find it hard to squeeze under the numberplate! In the absence of ramps it might be easier to use wooden blocks on the chassis rails and axle stands.

Check all the way round the seal that it hasn't been pinched or damaged. Examine the channel that the seal sits in and the top of the filter can that there isn't damage or dirt hiding in there (or even part of an old seal). I don't pay much attention doing a filter change so it is hard for me to remember but I oil the seal, fit it in place and then gently poke the seal at intervals all the way round with a screwdriver to make sure it is properly seated and that it isn't twisted. Then I offer up the can (which I have filled with oil but not absolutely to the brim) making sure to keep the bolt and washer pushed up against the bottom of the can (otherwise oil will pour out). I get the bolt thread started and spin the can and the bolt in unison until it starts to press against the seal. Then I get a socket on the bolt head and gently nip it up and that's it.

Stephen

[Chief]

I did mean the collar round the bolt at the bottom.

Currently it's now about 1 drip every 30 minutes, as I've checked twice now within an hour.

I do wonder if it would be more excessive if the enging were running, but I'm out of fuel (shame really as that was ethanol free fuel). I realise I can turn the engine with the starter, but of course there wouldn't be the vibrations of the engine actually running doing that.

The issue with axle stands etc. is the car's stuck on a part of the drive where it's not a viable option to safely jack it up (sandwiched between a hedge and a wall), hence the crawling underneath and it's sandwiched further in front and back with vehicles that can't currently be moved.

I don't think the seal got twisted/pinched as once it finally stayed in place I was able to run my finger round feeling it for any oddities before starting to scew up the housing. I did take some photos of it once the housing etc. was in-situ however my phone has decided it no longer wants to talk to my computer so that's taking longer to do or I'd have put them on this thread.

It certainly sounds like you don't tighten it anywhere near as much as I've had to just to get it to this point, or you don't know your own strength

***

The full story about the parts list is that I took off the whole assembly again about maybe three weeks or so ago.

In doing so I discovered the filter housing I had previously bought was damaged possibly a kerb or speed bump had taken it out (surprised I never noticed the damage when I bought it). I had also not realised that due to it being distorted the bolt would go straight and true, the housing would go on angled which may well have explained 2023's oil flooding from the top of the housing regardless of the top seal used.

I also distorted the oil pipe I'd bought last year removing it from the assembly, hence yet another replacement oil pipe - though this one fitted perfectly without any of the hassle of the last one so at least that was a benefit.

I replaced the housing about a fortnight ago, did everything up and had the bolt leak. I took it all apart again and noticed where the o-ring sits in the collar, the collar that had come with my Purolator housing was internally rusted and chunks were missing from it which I presumed was leading to the seal not properly making good contact at the bolt.

Although the o-ring was also new (in early 2023) I decided I'd buy both a new collar and o-ring so as to avoid any issues using old parts. On receiving the new collar/o-ring last week, I put them together dry and the fit was very good (certainly better than the old collar), so I thought I'd solved the issue of the bolt end leak.

[simmitc]

It might be worth replacing the O-ring with a fibre washer...

[myoldjalopy]

Are you sure you have assembled it correctly? You mention "the seal not properly making good contact at the bolt". But the seal is not in contact with the bolt head. The rubber seal sits inside the dished washer and the bolt passes through this washer and the seal from below before entering the canister. Thus the seal is sandwiched between the dished washer and the canister.

[Chief]

I used the term collar as that is what the spares sites call the dished metal washer but yes it is all assembled correctly (as far as I can tell from the diagrams on places like Moss etc.):

Bolt > Collar > Small O-ring > Housing

Then within the Housing:
Spring > Flat Washer > Stepped/Domed Washer (Moss call it a sealing washer, and I can't remember what it looks like now ) > Plate > Holding circlip > Oil Filter.

And finally the top filter head with the thick seal fitted.

I did go out again about an hour ago and did risk a further final tighten to the bolt and I'll just have to see the state of the drip pan tomorrow.

[philthehill]

Did you fit the collar the right way up?
The concave should be fitted upwards towards the bowl.
The bolt should only be nipped up and I suggest a further 1/4 turn applied.
Overtightening the bolt can distort the bowl and filter head.
The bottom of bowl may be already distorted leading to non sealing of the 'O' ring which fits inside the collar. Distortion of the bottom of the bowl is not uncommon.
I have tried a inch/pounds reading torque wrench on the bowl bolt and comparing it to tightening with a spanner and I cannot get the torque wrench low enough to determine a suitable torque setting.
When fitting the collar with 'O' ring installed - the 'O' ring should hit the bottom of the bowl before the collar. The ''O' ring is then compressed between the collar and the bowl and that compression provides the seal.

[Chief]

Yes the collar is the right way up as I was sure the o-ring should flatten out to create a seal in the same way that you describe in your last sentence since the housing shape makes it apparent the two slot together.

As far as you could tell on arrival of the "new" housing, the bottom of the housing was shaped as you would expect and I don't believe any distortion has happened through tightening.

I did wonder if the filter head was distorted due to the way the top seal kept drooping out, but since I later got it to the point where it seemed a correct fit as previously mentioned I presume it's okay - of course I won't know anything of the top until the whole housing has oil in it up to that level but I do admit I did wonder if it could get twisted through all the tightening.

I won't deny I'm somewhat concerned about just how tight I had to do the bolt up to get the leak to the point I last saw it at, I really don't think you could describe it as 'nipped up', more so, excessively tightened (at least by my own definition of what nipped up would mean).

[Chief]

So it appears that my final attempt tightening it last night succeeded in stopping the leak at the bolt.

I turned the engine over with the starter this morning and discovered I hadn't tightened up the oil pipe, that's because it started raining as I was fitting it a week or so ago and so I only finger tightened it and then thanks to the lack of good weather I'd forgotten about it

Tightened it all up, but it made no difference since oil still floods out of the union connector on the head.

I just want to check, is it possible to flood out the cannister if you're just turning the engine over with the starter? Is it possible that I've caused the cannister to fill greater than the amount of oil the use of the starter is able to output back out of the housing or do I just have a leaking union? (I know it used to be leak free at that point, but I really couldn't get it to turn any further either on the union into the head or the oil pipe nut).

Mind you, so far everything seems to want to be tightened more than I feel it should

[svenedin]

When you use the starter the oil pump at the back of the engine will be turning. This will fill the canister with oil in just the same way as when the engine is running. It is not possible to “flood” it because it is supposed to be full of oil. There is a washer where the oil pipe joins the filter head. Is it there? It’s very easy to cross-thread into alloy. If that has happened I’m afraid the filter head is wrecked.

Stephen

[Chief]

Is it there?

I take it you mean a washer where the oil pipe connects to the union? (and not the union connecting to the head?)

Either way, as far as I'm aware No, I don't have any washer there and none appears in either the Moss or ESM diagram that I can see:
https://www.moss-europe.co.uk/shop-by-m ... 51-71.html
https://www.moggyuk.com/catpage64.htm

[philthehill]

As regards the pipe from the block to the filter head the MOSS drawing is wrong.
There is an adapter that screws into the filter head and the pipe attaches to the adapter by a female union nut.
There is no washer between the adapter and filter head because it is a taper thread.
Some later non Minor filter heads had a parallel thread adapter and for that application I use a Dowty washer.

[Chief]

Thanks, the adapter is what I was calling the union.

[philthehill]

Thank you for the clarification.
Here is a Minor oil filter for sale on 'e' bay and it clearly shows the adapter/union which has a male taper thread which screws into the filter head and a female nut on the filter head end of the pipe.
https://www.ebay.co.uk/itm/364584673216 ... gKcwvD_BwE

[Chief]

I'm starting to wonder if the head really does have a problem.

The adapter leaks where it attaches to the head and I've tightened it so much the central 'nut' of the adapter is about 1mm away from touching the head, I know the adpter that went into the screw-on housing never went as deeply in as that and I presume that the nut part isn't meant to tighten all the way into the head?

Either way it's becoming a real strain to turn either the pipes union or the adapter.

I've also got a secondary leak and discovered that the housing is flush or very nearly flush with the top of the head on one side, so I presume it's metal on metal and not metal into top seal - maybe this has happened through all the tightening to get the bottom leak stopped.