Prefilling An Oil Filter with Prefiltered Oil

[Matt42]

The center hole in an oil filter for our Cummins engines is a regular old pipe thread. I think it's a 1 inch, but I would have to go look. When I prefill a filter, here's what I do.
1. Take the plastic wrap off the business end of the filter, not the whole filter. (I use a Fleetguard filter. No telling what gets into a boxed filter. )
2. Carefully inspect the threaded hole for burrs or leftover loose metal swarf from the threading process. Takes less than a second.
3. Grab a CLEAN piece of steel or plastic pipe of the same thread size and do the same inspection.
4. Thread the pipe in loosely about two turns, no more, as a plug. A plug would also work, if it won't shed plastic or cork or whatever. What I am using most often is a 3/4 inch copper sweat cap fitting. It sets in very nicely.
5. Slowly prefill the filter through the OUTER holes. This is slower, but the oil will enter the center of the filter through the filter media. Because I don't have four hands, I will sometimes do this from a quart bottle or a mostly empty gallon bottle from my last oil change. It also allows me to watch for teensy bits of aluminum seal I might have missed. (Haven't seen any yet. )
6. Wipe off spillage, remove the rest of the plastic wrap.
7. Remove the pipe and check again for pipe swarf.
8. Install normally.

 

[waltk]

You have me thinking... give provision to pull a slight-vacuum and this could be the "ideal-paranoid-owner-solution" i may adopt this, with vacuum...

Walt K.

The center hole in an oil filter for our Cummins engines is a regular old pipe thread. I think it's a 1 inch, but I would have to go look. When I prefill a filter, here's what I do.
1. Take the plastic wrap off the business end of the filter, not the whole filter. (I use a Fleetguard filter. No telling what gets into a boxed filter. )
2. Carefully inspect the threaded hole for burrs or leftover loose metal swarf from the threading process. Takes less than a second.
3. Grab a CLEAN piece of steel or plastic pipe of the same thread size and do the same inspection.
4. Thread the pipe in loosely about two turns, no more, as a plug. A plug would also work, if it won't shed plastic or cork or whatever. What I am using most often is a 3/4 inch copper sweat cap fitting. It sets in very nicely.
5. Slowly prefill the filter through the OUTER holes. This is slower, but the oil will enter the center of the filter through the filter media. Because I don't have four hands, I will sometimes do this from a quart bottle or a mostly empty gallon bottle from my last oil change. It also allows me to watch for teensy bits of aluminum seal I might have missed. (Haven't seen any yet. )
6. Wipe off spillage, remove the rest of the plastic wrap.
7. Remove the pipe and check again for pipe swarf.
8. Install normally.

 

[Matt42]

That would certainly speed it up. The method I use is slow, but it keeps stuff other than oil out.

 

[MChrist]

As a filter holder, I took some scrap pink foam insulation, stacked them so they were about 6" high, 6" wide, and about 8" long, cut out the center so they were just a little bigger than the filters we use, seal it all in duct tape, and poof!! A perfect platform to hold your filter steady while filling.

 

[Tim1]

All my life I have been prefilling oil filters without incident. After alot of reading about this, I have changed my ways and let the engine fill the filter now. Really is no big deal and figure that i beat the odds of contamination getting in there prefilling! Tim

 

[Wayne M.]

I have given thought about safely filling oil filters and Matt42, that sounds good. The main concern for us is pieces of the foil seal getting into the system and plugging the piston cooling nozzles. The RAM is the only vehicle where I prefill the filter- go figure. Anyway I do fill from the center, but I found some tiny fine mesh sink strainers at the dollar store that fit in the center real well. I just pour through that. I am considering going dry though.

I wonder what the time difference is in getting pressure with filled Vs. dry install?

 

[JR]

At around 20 GPM oil flow rate, probably not very long!

 

[MLee]

Chevron used to have that problem with the Delo. They revised the seal and its much easier to remove in one piece.

 

[waltk]

I can't help but repeat - the factory service manual tells us to pre-fill the filter... I shall continue to follow the instructions given there-in...

I would be particularly cautious about not pre-filling if still under warranty...

Just my paranoia... if in doubt follow owners' manual and service manual instructions...

Walt K

 

[Joseph Donnelly]

I have always pre-filled the filter from the center hole. I make sure the seal is completely removed, or at least there are no loose pieces. I also put a film of high pressure grease on the rubber square cut o-ring. The problems come from loose pieces of the seal, as noted aove, or dirt, from an owner or shop tech going too fast and being careless. I also carefully wipe the sealing surface area of the filter mount on the engine.

 

[jeepit]

I have always pre-filled the filter from the center hole. I make sure the seal is completely removed, or at least there are no loose pieces. I also put a film of high pressure grease on the rubber square cut o-ring. The problems come from loose pieces of the seal, as noted aove, or dirt, from an owner or shop tech going too fast and being careless. I also carefully wipe the sealing surface area of the filter mount on the engine.

Good idea with the grease Joe!

 

[leaky gasket]

I just changed the oil in my truck with Valvoline premium blue. The new Valvoline 1 gallon oil jugs did not have the foil seal. Just a screw cap With a bigger opening. When I saw it immediately thought of this thread and wondered what kind of havoc the foil was reaking.

 

[Killgore]

I pre-fill using a paint filter. Ed

 

[Gonzo 1066]

Just a observation, when I let my Cummins engine sit for several days and then remove the filter, the filter is less than half full as the oil drains back into the sump.. (this has happened with all 6 of my Dodge Cummins engines) Should I take the filter off and fill it before I start the engine if the truck has been sitting for more than 2 days??????

 

[Matt42]

Just a observation, when I let my Cummins engine sit for several days and then remove the filter, the filter is less than half full as the oil drains back into the sump.. (this has happened with all 6 of my Dodge Cummins engines) Should I take the filter off and fill it before I start the engine if the truck has been sitting for more than 2 days??????

I would not, unless the engine was known to be 1/2 quart low when shut off in the first place or unless you are going to change the oil. Eventually, you'll end up with too much oil in the crankcase unless the engine leaks or burns oil.

That situation is different from an oil change that begins with a fully empty filter. Even starting with a fully empty filter is not that big a deal, really. But it'll probably add up over time.

 

[seafish]

Matt42, pretty dam sure that Gonzo was being sarcastic in his last post.

 

[Gonzo 1066]

Yes I was being sarcastic, and I hope a bit obvious also. I have always tried to figure odds, that is what path will have the highest probability of success or failure. Being a bit of a diesel mechanic (professionally) for several decades, I have NEVER seen bearing wear due to oil changes or lack of startup oil pressure. Yes I have replaced rod and main bearings during engine overhauls, but most always the rings show wear much sooner than the rod and main bearings. This is due to the normal scuffing of operation and sometimes due to mistakes in the air filtration process. When in engineering school we did a test of running a diesel engine without any oil in the crankcase (drained oil from the pan) to measure wear on bearings. The film strength of oil is amazing in the fact that even with a 2 minute run (at idle speed) there was no indication of metal to metal contact. We never did this test with a load on the engine, and I assume that failure would happen quite rapidly under a full load condition. I do know that I will not convince any die hard filter fillers to change the practice that they do (like discussing religion or politics) but wanted to shed some light on the subject. Feel free to disagree, I will understand, but I feel that for the average guy there is more chance of causing damage to the engine from contamination of the filter than a dry startup.

 

[AEdelheit]

I agree 100% with Gonzo, never pre fill any filters, it will not the hurt the engine at, and can cause far more damage then good.

 

[Bob V]

I am an old time mechanic also and the only engines I have seen that the manufactures recommends to pre fill the oil filter has been turbocharged engines, gas or diesel. Its the turbo that needs the oil at start up, not the engine. I remember seeing the service bulletin on the turbocharged ford 4 cyl in the late 70s early 80s to pre fill the filter. I always prefill the filter, when practical, it gets the oil pressure up sooner after the oil change.
You old time TDR folk might remember an article from Cummins about piston cooling nozzles becoming clogged from the foil from the oil jugs. the only way it could get to the jets is from pre filling the filter. So I guess I agree that damage can occur if you are not carful, but if you pay attention, you should be fine. The oil out of the jug is probably cleaner than the oil in the engine.

 

[AH64ID]

I don't prefill, oil from the bottle is not as clean as it needs to be. The last report I saw was shocking.

The oil pump is rated at 20.5 GPM at 4200 rpms, it will be considerably lower at idle. That being said I have a oil psi gauge that gets it's reading from the main rifle above the ECM, and pressure builds nearly as fast as sitting for a week.