Here I am

Why is oil filter anti-drainback valve critical in vertical application?

Attention: TDR Forum Junkies
To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.

Thanks, TDR Staff

ATS - Cool people!

fass ??

One of the much pointed out weak points of a much maligned oil filter is its 'cheap' (poorly functioning?) anti-drainback valve. Just wondering why it's so critical in an oil filter mounted vertically? Don't think there's enuf residual pressure after shutdown to force the oil out of the filter (but what do I know), so why would a poorly functioning or even non-functioning anti-drainback valve present a problem at startup?
 
Because the engine runs for a little while at start up with no oil if it has to fill the filter first. Not sure how it does it but if I leave my drain plug out overnight the filter is only half full in the morning. It must be somehow siphoning, not sure if it's back though the anti-drainback valve or coming from the clean side of the filter. Never removed the filter without first draining the oil to see if it remains full or siphons out but don't see what difference it would make whether the drain plug is in or out. This has made me wonder how worthwhile it is to pre-fill a new filter with oil if it drains half way out when you park anyway. Perhaps just prefilling halfway is good enough, I know my oil pressure comes up fast anyway but can remember some gassers that have had the oil pressure idiot light come on for quite some time on the first start up after an oil change.
 
I've mostly driven & maintained gassers & have performed many, many oil changes since '82 & have probably pre-filled oil filters less than 10 times in all that time. And the only time there was a delay in oil pressure coming up after an oil change was when I did a big whoopsee -- put only 3 qts in a 5 qt system. Low oil pressure & the clattering got my attention pretty darn quick!



FWIW, a late 70's VW Rabbit I bought used with ~60K miles had over 240K miles using Fram oil filters & 3-4K mile oil changes before I consigned it to that great junkyard in the sky bc it was a rustbucket. But ... the interior was still like new & engine still strong & still getting good fuel mileage.
 
The problem with Frams wasn't just the anti-drainback (anti-syphon) valve. The internal sealing material would come apart and plug piston cooling nozzles. HERE is the TSB.



Rusty
 
Last edited by a moderator:
Fram's responce to the TSB

Cummins Bulletin® August 2002 TECHNICAL INFORMATION

It has been brought to our attention that a few DaimlerChrysler service

technicians are recommending that the FRAM PH3976 filter not be used on

Daimler Chrysler vehicles with the Cummins 5. 9L Turbo Diesel engine and

that use of these filters can cause damage to the engine. Daimler Chrysler

has informed us that they released a Technical Service Bulletin to their

dealerships communicating a potential contamination issue and recommending

the use of Fleetguard manufactured filters.

FRAM has been selling PH3976 filter for this engine application since the

engine platform launch and it has maintained an extremely reliable service

record. Late in 2000, Cummins and Daimler Chrysler brought to our

attention a low incidence failure mode in their Cummins 5. 9L Turbo Diesel

engine of the piston cooling nozzle plugging, resulting in engine failure.

The plugging was caused by contaminates lodging in the nozzle. The

contaminants included metal chips, calcium carbonate, polyethylene, and

styrene butadiene that are not associated with filter manufacture, and a

neoprene compound, which is used as a sealant on the tapping plate of the

filter. There were also several other engine warranty issues determined

unrelated to the piston cooling nozzle plugging that were part of the

engine failure sample. A small amount of neoprene rubber was used in the

FRAM filter as a sealant.

Throughout our investigation with Cummins & DaimlerChrysler on various

engine failures, no conclusive evidence was found to assign cause to

filters or other contamination sources.
However, driven to satisfy our

customers, the FRAM engineering team made modifications to the design

eliminating the neoprene and expedited development and manufacturing to

release a revised filter model number to PH3976A. With the design change

on the PH3976A completely removing the use of neoprene, there is

absolutely no validity in comments that the Fram filter should not be used

for this application or that it may cause engine failures associated with

plugged nozzles.


The Honeywell Consumer Products Group warranty policy also protects the

consumer if it is determined that a FRAM filter is responsible for damage

to an engine due to defects in design or workmanship. This information

should be openly conveyed to our customers if they have any concerns or

apprehension about using a FRAM filter for this application.





If I'm not mistaken DC has withdrawn that TSB under threat of lawsuit from Fram. They're still cheap filters though and I wouldn't use one.
 
I was aware of the TSB but NOT Fram's threat of a lawsuit! Very interesting.



All this negative info on the Fram has got me concerned enuf to buy a # of filters for disassembly & inspection. So far I have 2 Frams -- the regular & Xtraguard -- plus Wal-Mart's brand. I'll also be buying a Purulator(sp?) & local chain store's store brand filter. Once I've got them disassembled I'll compare their overall construction, material types & form my own, purely subjective, opinion of their respective quality (or lack of it). Will say tho, that my bias will be toward determining if a filter is "good enuf" for my 3K or so mile oil change intervals. For me, that's all that matters (at least until my 1st engine failure :{. None so far in over 20 yrs of oil changes, but then, until recently, all my vehicles had been gassers).



Thnx all.
 
There was a write up in the magazine a year and a half ago on that very subject. Might read it and save yourself the money, unless you just like to take stuff apart and see what's inside.



Daniel
 
I've only been a member for about 6 months so don't have access to the article, but thnx. Besides I'd like to see for myself to make my own judgement on whether the risk is worth it for 3-4K mile oil change intervals.
 
Thnx illflem for the link but I've known about that 'study' for some time & have it bookmarked (somewhere). Interesting to re-read it tho.



Since the study is a bit dated & I'd like to confirm for myself his general 'findings' I'll eventually get around to cutting the few oil filters I've collected & forming my own opinion. Tend to be veeeery skeptical of any such 'studies' & especially anecdotal, so-called, failure 'evidence' since, I believe, ignorance (lack of knowledge) skews any 'conclusions' (obviously). I'm guilty of same on a pretty regular basis, only realizing after the fact ... whoops. But then, I may be more self-critical (objective) than the average person (I'm just so special :eek: ... hyuk, hyuk).
 
If I may throw my observations in here, have you ever filled the filter to the top and then WAITED? If you give it a minute the oil level will drop to about half full. I usually need to refill my filter 3 times to get it just over 3/4 full before install. I suspect that a similar action happens when the engine is running as oil flows THROUGH the filter (not simply sitting soaking the media) it does not saturate the media as much. I think you are simply seeing a settling of the oil in the filter after it sits for a while.



JMHO.



Scott
 
A few weeks ago I ran into shoe salesman that has nearly 300k on his Dodge Cummins all with Fram filters. He changes on a regular basis, too. He also has a stock clutch.



I believe the greatest number of plugged cooling jets was from people letting the foil seal fall into the oil jug and then filling the filter with that same foil seal?



I've filled used filters with oil and it did not drop in level. The media is already saturated and does not absorb.



Bob is the oil guy http://www.bobistheoilguy.com/ is performing dynamic testing on filters. Intersting data collected to date.
 
pm720, I noticed the same thing on one of the few times I pre-filled a new oil filter. Acccidental discovery, as I had pre-filled it, then set it aside & when I finally picked it up to install it I noticed the oil level had dropped. Can't remember how many times it took to actually fill it but I think I finally gave up & just installed as it was.
 
Back
Top