Need A Purolator Oil Filter Guru!

[HammerDown]

On my 1981 Corvette (5.7/350) and for the longest time I used 'Purolator Premium-Plus' oil filter #L20049
Well, low and behold the Purolator bean counters got a hold of my trusty filter and chopped it to a stubby, lower capacity filter #PL15313
The ONLY reason they did this is to make this new-short filter fit more applications.

I got on Purolators application guide, entered a 1970 Chevy Suburban 5.7/350 and 7.4/454
They both take the Purolator #L34631 which is their "classic" filter and a nice deep filter.
It's even a little longer 'can' then the L20049. It has the same diameter hole, thread pitch, outside-can diameter, rubber gasket...and it fit up under my 1981 Corvette with ease!

Here's the question...the holes where the dirty oil would enter seems to have a rubber valve, maybe a 'anti-drain back valve'? When hand filling the older L20049 oil would drain through the little holes into the filter. HOWEVER, with this L34631 the oil won't pass through that black rubber liner/valve?

Is that an anti drain back valve that allows pressured-oil to pass-through and, do I have anything to worry about...think it's ok to use the L34631? I like it because it's a nice deep filter!

Thanks for any feedback, Ray

 

[Coprolite]

Ray, I believe the anti-drain back valve is more of a one way valve.

Whether or not the filters you mention are adequate for your application is beyond my quick reference material. Good luck finding the answer, I am sure you'll have one soon with the guys on this site.

 

[HammerDown]

Originally Posted By: Coprolite
Ray, I believe the anti-drain back valve is more of a one way valve.

Whether or not the filters you mention are adequate for your application is beyond my quick reference material. Good luck finding the answer, I am sure you'll have one soon with the guys on this site.


I'm thinking that black rubber is a one-way anti drain back valve.
Of course I called Purolator for answeres and because of 'liability issues' the 'rep' wouldn't tell me it's "ok" to use the L34631.

But, when I cornered him about the L20049 being 'shortened' to accommodate MORE applications his reply was..."well the L15313 is shorter but improved". (yea ok)
Avoiding my question, he chuckled then more or less agreed with me.
The now shorter L15313 also fits 4 cylinder engines...and THAT is why they made my prior L20049 shorter.

Ha, I just found this...so I believe I'm SAFE!
" Purolators website lists 815 applications for the L34631 oil filter for GM vehicles from 1964 to 2004 - various gas and diesel GM engines"

 

[HerrStig]

If your filter is mounted BASE UP you do not need an antidrainback, but the presence of one will not hurt.

 

[beanoil]

This ^^^

Same situation as the PF61,and PF62 for the Trailblazer/Envoy. One without, one with the ADBV.

 

[dnewton3]

Yes, the outer ring of holes is the entry for oil; it comes out the center tube.

That being said, the ADBV is the rubber (or silicone) barrier that seals those holes. But, it is supposed to be biased against the base plate, otherwise it would not function as an ADBV when the engine shuts down. That rubber needs to "relax" against the base plate to seal those holes.

When the engine is started, the pump has no problem whatsoever pushing the rubber away from the base and flowing as desired.

But, you probably cannot get oil to "flow" past the rubber just holding the bottle and filter in your hand. Gravity is not going to have enough "oomph" (force) to open the natural bias of the rubber ADBV.

Depending upon your OCI, you likely have no need for a larger filter anyway ... I suspect your car is probably baby'd and sees relativly few miles. It's fine to want a larger filter, but I doubt the reccommened smaller one would have any ill effect whatsoever.

Don't overthink this. Just put on the filter and be done with it; there is no need to prefil the filter. Note that I said "need" and not "want". A few seconds of dry start will not ruin your engine at all. There are many of us that never pre-fill a filter, and yet our equipment survives just fine. I have two vehicles with over 200k miles on them; never had a "pre-filled" start in their life. And yet my UOAs show them to be in excellent health.

In short, this pre-fill topic matters to your brain way more than it matters to your engine.

 

[BlueOvalFitter]

Originally Posted By: dnewton3
In short, this pre-fill topic matters to your brain way more than it matters to your engine.

It helps me sleep better at night.

 

[dnewton3]

Originally Posted By: BlueOvalFitter
Originally Posted By: dnewton3
In short, this pre-fill topic matters to your brain way more than it matters to your engine.
It helps me sleep better at night.


Nothing wrong with that, as long as that's the primary goal.

 

[HammerDown]

Fellas, thanks for all the feedback...the L34631 is on, ADBV or not, I feel good about this filter and feel I made the right decision. (no stubby little 4-cylinder for my Vette)

I may even use the L34631 on my BBC Jet Boat!
BTW, 40+ years ago my father tough me to pre-fill filters...don't think I can change my ways now, it kinda comes naturally

 

[901Memphis]

I always pre fill filters and turn the engine over with the fuel pump off to prime it.

It's gotta be super easy to prefill a vertical filter but bit of mine are angled so I can't fill them to the top.

 

[steve20]

Me too.....been pre-filling them since 1972, and 5 days ago I just taught my 14 yo son to do the same. He is now taking over the oil change responsibilities--with supervision of course