Oil filter leak

[Dirtman]

Found the cross reference. Wix 51515 is a motorcraft FL1a match. So I'm stumped.... maybe it does take the fl810s if the fl1a doesn't work. Or, it could be the sealing surface on the block.

 

[Grumpaw]

That also...the OP did state the the surface was pitted. Maybe not much, but enough to cause a dribble leak.
Usually those gasket surfaces are machined very smooth. Don't ever recall seeing one with a rough or pitted surface.
Grumpaw

 

[adsm08]

The OHV 4.0 used the FL1A for its entire run.

The SOHC 4.0 was introduced in 97. It did not start using the FL820S until mid-2001.

The filters use the same gasket. The FL1A has a massive thread hole, while the FL820S is rather small. You absolutely cannot accidentally interchange the two. If you try to put an FL1A where the 820 belongs it will slide on and then fall off and hit you in the face the second you let go. If you try to put an 820 in where a 1A belongs it just won't go. The hole isn't even big enough to cross the threads. I have tried doing this both ways due to the mid-year change and just grabbing filters out of my cabinet before looking.


If the sealing surface is pitted that is probably the cause of the leak. Take some black RTV sealant, dab it on the pits, and then wipe backwards with a brand new razor blade. This will fill the pits and give the gasket something to seal against. You may need to clean the surface several times before doing this as it will need to be kept free of oil during the process.

 

[Bird76Mojo]

Don't forget to also oil the surface of the "gasket" before you install the filter. If they're installed dry, they can wrinkle or wad up and cause leaks.

 

[Grumpaw]

The OHV 4.0 used the FL1A for its entire run.

The SOHC 4.0 was introduced in 97. It did not start using the FL820S until mid-2001.

The filters use the same gasket. The FL1A has a massive thread hole, while the FL820S is rather small. You absolutely cannot accidentally interchange the two. If you try to put an FL1A where the 820 belongs it will slide on and then fall off and hit you in the face the second you let go. If you try to put an 820 in where a 1A belongs it just won't go. The hole isn't even big enough to cross the threads. I have tried doing this both ways due to the mid-year change and just grabbing filters out of my cabinet before looking.


If the sealing surface is pitted that is probably the cause of the leak. Take some black RTV sealant, dab it on the pits, and then wipe backwards with a brand new razor blade. This will fill the pits and give the gasket something to seal against. You may need to clean the surface several times before doing this as it will need to be kept free of oil during the process.

Sir, I stand corrected. Never thought about different thread sizes. No way the FL820S would fit. At times in the past I've had 2 Ford at the same time. One used the 820S ( my Ford E-450 motor home with a V 10) and a Mustang that used the FL1A, and had both filters on hand. Never thought about comparing them for different thread sizes.
I learned something today.
Grumpaw

 

[adsm08]

Sir, I stand corrected. Never thought about different thread sizes. No way the FL820S would fit. At times in the past I've had 2 Ford at the same time. One used the 820S ( my Ford E-450 motor home with a V 10) and a Mustang that used the FL1A, and had both filters on hand. Never thought about comparing them for different thread sizes.
I learned something today.
Grumpaw

I never really thought to sit down and compare them either until one day on the lube rack I had two 01 Rangers in a row come through, and had filter problems on both, because my book didn't really reflect the mid-year change for the 4.0.

After I got them done I was out of work for a bit, so I pulled one of each filter out and looked at them side by side.

 

[dltrial]

I guess I'll go to a prts store and make a comparison of the two.

Derek