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MG TD TF 1500 - Lost All Oil - TF Filter Canister

I hope that you can help me ...

> What do you think made the Purolator oil filter canister on my TF681 lose 4-1/2 quarts of oil in short time?

> What can I do to prevent it in the future? (Never had this problem before with TF681 or TF7211). Don't want to convert to spin-on filter.

> How badly do you think that I damaged the engine? How can I tell without removing the sump?


I may have severely damaged Jo Ann's TF 1250 engine yesterday. Test drive after an oil change and unrelated engine work. The canister was dripping a little before I left, so I tightened it enough to stop the drip before I left on the drive.

Oil pressure good. Temp good. A couple of runs to 50 mph, most around 35-40 mph. After about fifteen miles, I stopped to make turn at traffic light. Severe rod knock, low RPM. Only a few seconds. Pulled to the shoulder and turned off engine.

Checked for drip at canister. None. Checked oil. NONE, clean dipstick.

Started engine and pulled across the street into a 7-Eleven. The gauge still showed pressure. Trail of oil behind car. Small puddle under the pump/canister. Don't know how long the engine was near empty; probably five miles or more.

Today, I drained 2 quarts of the original 6-1/2 quarts from the sump and removed the filter. The bolt in the canister was easier to turn than it had been before the test drive, which makes me suspect the O-ring.

The canister is an original Purolator canister because I saw the ghost of the Purolator decal before I stripped and repainted it.

I used the middle size O-ring that comes with Wix 51300 oil filter as I always do. The O-ring was firmly in the groove in the oil pump and is the same diameter as the canister.
Large = .124" tall X .119" inside to outside
Middle = .173" tall X .087" inside to outside
Small = .124" tall X .067" inside to outside.

The paint at the opening of the canister is pushed back from contact with the oil pump. The O-ring will not slip over the outside of the canister. I tested and couldn't do it. Possibly touched the inside of the oil pump(?) The paint on the canister was dry, painted a month ago. Didn't see this when I painted the canister for the other TF.

Don't know what damage done to the engine. Don't see any sparkles in the oil. Gonna install a new filter after I read your suggestions to avoid the problem, fill with VR-1 oil, start the engine and listen. Doubt that I will drive it 250 miles round trip to GOF-South in Gainesville FL in two days.

Thanks for your help,


LM Cook

Sorry to hear that happened. It's impossible to say anything for sure without being there, but I would guess the o-ring slipped a little and got pinched. Then when you tightened it further, it split the o-ring.

The knocking is certainly scary, but if you had oil pressure then I think you'll be ok. I would certainly run the engine and see what happens rather than tear it apart. Even if you did damage to the bearings, it might be fine to continue driving.
Steve Simmons

I had this happen a couple of years ago but I only drove around the block, about 3/4 mile. I found that when I changed the filter and replaced the gasket, part of the gasket had twisted while going in. I make sure that I oil the gasket before inserting it now, and check for that leak before I leave the garage after A filter change.
John Golles

I am so relieved!

Two friends who vintage race TFs and a long time MG expert in our club told me the same thing.

Tomorrow, Iíll install new filter, fresh oil, test drive a few times, look for leaks, listen for noises, and pack my bags for GOF-South.

Thanks for your help.

LM Cook

Hereís hoping your journey will be uneventful.

W A Chasser

I replaced the seals and clip inside the canister, installed a new Wix filter and square O-ring, filled with VR-1, and took it for another test drive. Perfect - no drips, engine sounded happy.

Polished the car. Ready to drive 300 mile round trip to Gainesville FL for GOF-South.

Started the engine to pull into the garage and the flood gates opened. Oil was flooding from the canister where it joins the pump. Happened all at once at startup. Luckily it happened before we left in it for GOF.

Iíll post a video and other info when we return home (in my Hyundai). Maybe I will find the answer from MG experts at GOF.

LM Cook

Are you positive you didn't already have an old gasket in the pump when you added a new one? Sometimes they are very hard and tough to see/remove. That's the most common reason why a pump leaks oil from where you describe.

Go ahead and replace the cannister with a modern spin-off filter unit from Bob Grunau, or Butch Taras. Better filtering, cleaner, cheaper.

Tom Lange
MGT Repair
t lange

I agree with Tom...originality only goes so far.
Gene Gillam

I agree with Tom as usual. An old seal can definitely cause issues. I wonder also if there is something wrong with the assembly of the parts, and the canister is being pushed away by sudden excessive pressure? It's a long shot but if something is happening to suddenly increase pressure and the canister is only being held in place by spring pressure...

Unless you're going for concourse points, I agree that spin-on adapters are the way to go. I put them in just about everything, the only exceptions being my SA, which is very original, and the MGC, which is done very period correct and the filter is right on top of the engine. If you want a period look, buy a K&N HP-2009 filter and paint it and the adapter engine color. It will fool most people.
Steve Simmons


Without a doubt, the old system had it problems. More than once, I dumped a fresh load of oil on my garage floor.

Tom Lange gives good advice. Switch to the newer screw-on filter. I got mine from Bob Grunau - never looked back.

Gord Clark
Rockburn, Quť.
Gord Clark

I know you are striving to keep the old girl original But this is one of those things that needs to be sorted out. Switch to the spin on filter and give yourself peace of mind. Have had this issue but not to your total lose level, in the past and made the change and not looked back.
Would also recommend the Anti Roll bar on the front suspension. So simple to do and it really makes the drive SO much better. We are driving our MGs in the 2000's now so a 5-speed gearbox and better axel ratio will allow you to drive safely on modern highways.
Also really impress the opposition that your 60+ MG can still cut it with style.
Rod Jones

If it is a seal problem it will still be there with a spin on conversion.
I do agree that a spin on conversion is a good idea. I am a cheapskate and made my own :-}
Ray TF 2884
Ray Lee

Could the centre bolt be starting to strip its thread? The oil pressure may be enough to pop the bolt a couple of threads causing the leak.
M Magilton

Rod, off the topic of the thread, but since you mentioned it, I saw nothing in your list of modifications that was safety related. Were you referring to the engine rpm at road speeds?

In regard to this thread, I also changed over to the spin in filter mod, it is easily reversible so I kept all the original hardware.. if there is gas available for purchase, the next caretaker they can switch back if they do choose.

Regards, Tom
tm peterson


Vintage MG racer George Pardee, and builder of the XPEG engine in my other TF also feels that the threads in the adapter or canister bolt may be stripped. Jo Ann and I return home from GOF-South today. Iíll investigate the bolt and adapter tomorrow.

LM Cook

Is it reasonably easy to remove the adapter with the oil pump attached to the XPAG engine while itís in my TF?


LM Cook

Yes it simply threads in place where the canister bolt went.
But it wonít change a thing if you donít insure ALL old O-rings have been removed from the oil pump groove. Get an ice pick and dig around in the groove.

When you get home see whether you can tighten the bolt up more before removing. This will be the indicator that the threads have pulled. Although when you torque it it up if itís not suddenly releasing the. Pulled threads are unlikely in my
opinion. But I have never dealt with later XPAG pumps.

W A Chasser

The bolt inside that oil pump that has to be removed to install the spin-on filter can be very very tight. I used an Allen key and a BFH to shock it off. Best done on a lift where you can get a good swipe at it.

Declan Burns

Lonnie, this is from Bud's TTalk:

I followed it for my TD and have had no problems.

J K Chapin

Jo Ann and I are back from GOF-South. Drove my Hyundai instead of the TF. Started working on the leak again today.

Here is a recap and video of my oil canister leak. Still looking for a solution.

> I do not (yet) want to convert my oil filter to an aftermarket spin-on filter.
> I may have confused some readers by referring to the female threaded tube for the oil canister bolt as the "Adapter." It is called the Adapter, and also called the "Center Tube."

The oil filter canister is the original Purolator canister. 10mm bolt through canister and filter into pump. I have successfully changed the oil and filter in the car at least twice before the current problem. Plus, numerous times in my other TF with the same type of filter canister.

Engine is early TF1250 (XPAG/TF/30452). Unknown history. Car purchased one year ago.

>>> 3-Apr-2023 approx
Inserted a penny under the relief valve spring in the pump to increase low oil pressure. Did not start the engine. Gauge pressure is read at the head, not at the block.

>>> 17-Apr-2023
Filled sump with 6-1/2 qts Valvoline VR-1 20-50. A few small drips from canister at the oil pump. Stopped with a quarter to half turn of the bolt. Drove 15 miles with a few stops to check for drips and to check oil level. Good oil pressure and temp.

Sudden rod knock. Stopped engine pulled to shoulder of road. A few drips on oil canister. NO OIL on dipstick. Started and drove across road to 7-Eleven. Trail of oil behind car. Tow truck delivered to my house.

>>> 19-Apr-2023:
Drained sump ... only two quarts remaining in the sump. Replaced seals inside canister. Replaced square rubber O-ring and filter, although they looked good. Filled sump. Approx 20-min test drive. No drips. Good pressure and temp.

Returned home. Washed car. A few hours later, started car. Oil flooded from canister. Did not lose oil pressure. YouTube video begins immediately after startup as described above. Yes, you hear rod knock as pressure builds. Was worse and lasted longer before I added penny under relief spring.

>>> 24-Apr-2023:
Removed oil canister and filter. Square rubber O-ring was in the correct location. No kinks, splits, or damage. Filter looks good. Canister components look good.

Threads on the bolt and in the Center Tube look good. Bolt threaded sufficiently deep into tube. However, the bolt fits loosely enough to move up and down when fully threaded into pump. Almost like a 3/8 bolt in a 10mm nut. Don't know if this is a problem or if it was designed this way to allow the bolt to move enough to insure a solid square seat onto the O-ring in the pump. Is the movement normal?

I feel that there are three ways that oil could escape as shown in the video. Not sure why the problem doesn't show immediately. The oil filter element, spring, plates, etc. inside the canister have no effect on the seal of the canister to the pump.

1) Cracked pump
I can't see any damage.

2) Canister not squarely seated onto the O-ring and pump.
Possible. I will address that possibility soon.

3) Canister moving away from the pump.
I will replace the Center Tube and the Center Bolt if we decide that they are the problem.
JUD: Thanks, I'll try the tip on Bud's site to remove the Center Tube. Any other suggestions to remove it?

Thanks for your help,


LM Cook

Lonnie, you say the oil filter,spring,plate etc inside the canister have no effect on the seal of the canister, have you checked if they are assembled correctly, as when I change my filter, I feel spring resistance on the canister,and have to put pressure on canister(longitudely) while I do the bolt up.I don't know if this makes a difference or not. Hope you find the problem. Cheers.
Ralph TF9181.
R E J Stewart

From the video it just looks like an O ring issue
Suggest you measure the width of the O ring groove in the housing and make sure you're using the widest ring that'll fit in there
Check the groove for foreigners-get it clean, fit the new 'lubed' O ring--offer up the filter and housing and do the bolt up just enough so you can wiggle/twist the housing around on the O ring to make sure it's in place nicely then tighten the bolt
Are you doing the centre bolt up tight enough, don't be afraid to tweek it up and retighten warm --i usually do them up about as tight as you'd get with a stumpy(6")spanner so that'd be probably 25ft/lb ish and get it warm and retighten
Usually when doing a filter change I tend to leave the O ring alone and don't replace it unless there's been an issue---why fix somthing that's not broken

William Revit

I have just checked the seal in my spare engine and it is the your top one approx 0.067 x 0.119
I think the middle one is too tall and too thin allowing it to displace and not let the canister
self centre.
Ray TF 2884
Ray Lee

Lonnie, I just went back and reviewed my Ttalk page about the adapter, . I note that I show a vernier caliper measuring the proper o-ring as being .088" wide. Is that what you're using? Bud
Bud Krueger

The image from the web site. Bud

Bud Krueger

Install the canister without an o-ring. Mark how far into the pump housing it goes. Then install an o-ring and compare how far it goes in. It should be a lot less. If not, something is hanging up. Also double, triple, quadruple check that there is nothing in the o-ring groove. Not even a tiny piece of an old o-ring. No burrs either, on canister or pump. Use a sharp metal pick aggressively to make certain there is nothing there but metal. The o-ring should completely fill the gap it inserts into and not be loose.

By the way, if anyone is looking for a spare pump and filter assembly, I found a couple of them last night while cleaning out my unneeded spares.
Steve Simmons

Just a thought. Your oil pressure is read at the head, not the block fitting. You probably should relocate this to get an accurate reading. Once, many decades ago, when my pressure was measured at the head I put a small washer under the relief valve, started the engine and even at idle the pressure shot up to over 80 and pegged the gauge. Immediately shut down and removed the washer. I wonder if you could be inadvertently running excess pressure with the penny installed and that is causing the filter to leak?
John Quilter (TD8986)

I just measured the seal seat. it appears to be
0.170 deep and approx 0.090 wide.
The correct seal should be under 0.170 deep to allow the canister to enter before hitting the seal. The large one would probably fit.
I tend to rotate the canister to make sure it enters the groove before fully tightening. This is more important if the bolt is wobbly.
Ray TF 2884
Ray Lee

I wonder if maybe while the filter was apart that mistakingly the bottom plate may have been fitted wrong side up and the spring is bottoming out preventing the canister from reaching the O ring properly---most likely not but worth checking
William Revit

Iíve been down with a cold/allergy since we returned from GOF.

My other TF has an identical Purolator oil filter canister. When Iím feeling better, Iíll remove the canister from my other TF and compare the two.

LM Cook

This thread was discussed between 18/04/2023 and 01/05/2023

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