AC Delco PF 25
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Navigator
Joined: Oct 2010
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AC Delco PF 25
On Rock Auto they have PF 25 oil filters for $7.29. When getting ready to place an order for a couple of them i noticed it says WITH OUT Anti Drain Back Valve. Does the 1975 Corvette need an anti drain back valve or would it be ok to use these in the 350 engine? I have concerns about this and am clueless. Your thoughts suggestions would be greatly appreciative.. Thank You.
Racer
Joined: Sep 2017
Posts: 338
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Hi. I would think an Anti Drain Back Valve is not needed on our 350. The filter is upside down, "in and out" at the top of the filter and basically full of oil so it can't drain anywhere and won't need to be refilled on start up. One less thing to fail. If that is the correct purpose of an Anti Drain Back Valve.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
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From: Cool Northern Michigan
The Anti-Drain feature is needed when the filter is at a 45* angle or more.
You will see this on modern cars & trucks and some old Fords where the filter attaches to the block almost horizontal. The oil could actually drain back into the pan leaving it empty at start-up..
Not even close with SBC & BBC vertical filter.
You will see this on modern cars & trucks and some old Fords where the filter attaches to the block almost horizontal. The oil could actually drain back into the pan leaving it empty at start-up..
Not even close with SBC & BBC vertical filter.
Last edited by HeadsU.P.; Sep 7, 2021 at 07:01 PM.
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Some places have superseded the AC PF 35 with PF 1218...
Team Owner
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Around 20 years ago, right before Kmart went out of business in my area, I bought their entire stock of these. I had no issues for PF25 filters, probably have 40 of them still on the shelf it should last my lifetime