View Full Version : 347 7 quart pan drain plug seal help!!
yel911
09-14-2020, 06:07 PM
We have a 2009 347 Ford Performance motor with a "flat" 7 quart pan. The drain plugs have leaked since day 1. I bought 1/2"x 2mm thick aluminum crush washers that seem to work on the rear, but not the front. I've tried doubling up, no luck. The bolt seems to have a section before the head that isn't threaded. I have no clue. Any ideas?? Thank you in advance.
Norm B
09-14-2020, 06:52 PM
Not trying to be a smart a$$ but, buy a new plug. Most automotive stores stock a selection of plugs of different sizes and thread patterns.
Norm
I'm a fan of crush washers on oil drain plugs as well, but I wouldn't recommend doubling them up. Sounds like the bolt is your issue and I would also recommend simply replacing it.
You might try hydraulic sealing washers -- I've used them before with success on leaky drain plugs. Order the size you need, they look like this: https://www.mcmaster.com/93781A033/
CraigS
09-15-2020, 07:11 AM
Either the washer NAZ shows or a new bolt. I have come across those bolts also and assume they originally came w/ a special washer. I think that necked down area allows the washer to fall off center and then it doesn't seal properly.
davekp
09-15-2020, 07:18 AM
Stat-o-seals or dowty seals. Napa has them but I'm not sure what they call them.
Stat-o-seals or dowty seals. Napa has them but I'm not sure what they call them.
They're called Dowty Seals because they were made by the Dowty Group and also called bonded seals. They are used in hydraulic systems. If you click on the McMaster-Carr link in Post #4 you'll see a drawing of a similar type but this one is designed to stay with the drain plug.
Railroad
09-15-2020, 02:59 PM
You might check the face for the compression ring on the pan, for squareness and smooth surface.
TMartinLVNV
09-15-2020, 04:34 PM
I've put these on my cars for the last 25 years or so. Always work great and never need a wrench on the plug again. It does take a little longer for the oil to drain, but I'm not in a hurry. I also put a rare earth magnet on the drain pan next to this valve. Then, I remove it before opening the valve to drain. I've never had any sort of leak from them.
https://www.fumotooildrainvalve.com/f-101.html
There are quite a few variations for different applications.