Fuel filter condition monitoring

[STEVEBROOKS]

From reading various posts, I gather a way (the best way?) to determine when to change fuel filters (other than mileage and/or age) is to monitor pre- and post-filter pressure differences. Is anybody doing that? Being that I have two filters in the line, I assume I'd need one reading between the in-tank lift pump and the factory canister, another between that and the GDP filter, and a final one between that and the CP3 pump. Does anybody have a gauge setup like this? If so, what locations/methods did you use to tap into the fuel lines and what pressure difference do you use to determine when to change filters?



Thanks,



Steve

 

[SHobbs]

Fuel pressure is a good way to keep an eye on them. I measure the fuel pressure just before the injection pump and see 16 p. s. i at idle. When I see the pressure get down around 14 or below I start thinking about changing the filters. The idle pressure is not as important to me as the pressure while running down the road where I like to see it stay above 10 p. s. i. I currently have my l. p on the frame infront of the tank with two filters infront of that. Things are a little different with the 3rd gens. , maybe some will chime in with something more.

Far as the lines I have 1/2" rubber line with AN fittings from the tank to the injection pump. I put in a "T" then run a grease gun hose to the pressure sending unit. Factory filter canister is gone due to constant leaks and some parts for it being discontinued. Not sure what has changed recently with the fuel I have been getting but, I used to get about 5 months on a set of filters. Lately I am lucky to get 2-3 months between changes.

 

[TCDiesel]

I am going to melt this snow Ball,I have let these post go on for Years its time to put an end them, How are going going to Measure filter life? when You have a pump that creates Vacuum after all filtering is done and pressure prior to filtering, How are you going to over come the low pressure metering circuit on the CP3? What is the mathematical equation to the Pressure Vs Vacuum and volume? Pressure loses before and after filtering would only be a touch tone and in most cases NOT be accurate the only way to correctly meter filter life is a Vacuum/pressure Gage ( one that shows both) after filtering at idle when all the return rates are equal ,and under load pressure should raise and vacuum will drop form normal when filter is dirty.

 

[CDonaldson]

This ^^^^ is the main reason I just decided to change my canister fuel filter at every oil change, and change my GDP 2-micron filter every other oil change. I'd rather put money in filters than expensive engine parts.







CD

 

[TCDiesel]

Yep just change at regular intervals and NEVER, NEVER remove the factory canister filter unless its absolutely necessary . . or for performance reasons, it is Not restrictive and adds filtering, if contamination happens the Insurance company will cover the LOSE IF the factory system is intact, Plus its much easier for visual inspection on contamination,I had 2 customers denied coverage on contamination. BC NO factory canister. If you suspect trashy fuel investigate ASAP,if you have spin-ons cut them open and inspect if contaminate drop tank and investigate.

 

[cerberusiam]

If so, what locations/methods did you use to tap into the fuel lines and what pressure difference do you use to determine when to change filters?

Read the pressure as delivered to the CP-3, only place you need a gauge. Pressure is a measure of resistance to flow, when the pressure at the CP-3 drops below the minimum you need to investigate. If you ever get to that point change both filters as there is a good chance the contamination is in both of them.

I am going to melt this snow Ball,I have let these post go on for Years its time to put an end them, How are going going to Measure filter life? when You have a pump that creates Vacuum after all filtering is done and pressure prior to filtering, How are you going to over come the low pressure metering circuit on the CP3? What is the mathematical equation to the Pressure Vs Vacuum and volume? Pressure loses before and after filtering would only be a touch tone and in most cases NOT be accurate the only way to correctly meter filter life is a Vacuum/pressure Gage ( one that shows both) after filtering at idle when all the return rates are equal ,and under load pressure should raise and vacuum will drop form normal when filter is dirty.

Todd instead of melting a snowball, I have no idea what that has to do with fuel filtering, why don't you try to communicate your ideas in a logical succinct manner?



(I have to do this with clients ALL the time when to keep projects from derailing)





Todd, I have adsolutely no idea what you are trying to say. Save the shotgun approach for bird hunting, it doesn't work well in a techincal discussion.

 

[TCDiesel]

Cerb. . You know I don't give a rats *** about INTERNET Hype,its always 1 Guy with 1 Truck that promotes some advertise POS setup,Don't get me wrong their is a wealth info to be found (And Great Products) on the Net,Cerb I received 10 CP3s this week all destroyed By trash,and most of the destruction with the NET hype setups, I always tell the owners wait until the dust settles before complaining , Cerb I have challenged and call out many manufacture(s) NONE have taken up the cause, How could you believe anyone or company that recommends removing filtration to install their setup WITHOUT ABSOLUTELY DEMONSTRATING ITS OUT COME, I type lousy. That's why I aways suggest to Call. Cerb You are welcome to call anytime, You convey the message much better then me on the NET.

 

[CKelley1]

the best way to determine filter change interval is as stated above with a gauge on the cp3, when the pressure drops from 8 psi to about 2 psi under load it is time to change. the filters have many different size holes in the media the larger holes has less restriction to the flow therefore mor fuel goes through the larger holes and they clog up first forcing the fuel to be filtered through smaller holes as the process continues the filter will filter its best at the end of its life. if you change the filter before this point your throwing a 2x better filter away than the new one your putting on.

 

[AH64ID]

If you are monitoring pressure after all the filters, and just before the CP3 you CAN get a good indication of filter life. Yes the CP3 can draw a vacuum, but that will show up on a pressure gauge. If you still have good pressure then you are not plugged and sucking thru the filters. I usually tell people that if your gauge goes to 2-3 psi WOT then it's time for a new filter, or a bigger pump if your making that much hp. Bosch specs -5 to + 15 psi at the inlet of the CP3, but reading +3 is easier than - 5. This is NOT a substitute for a regular filter change interval, just an additional way to monitor the system.

Todd like to talk trash about internet hype fuel filtration systems, but the simple fact is the one filter on his truck is rated lower than any setup of anyone in this thread. He feels thru his experience that the people that rated his filter were wrong and runs it, that doesn't work for 99% of people. He also talks about internet hype systems, but has yet to mention what system(s), even thou he has been asked repeatedly. He want's to kill the snowball but the way he talks about filters doesn't do much but get his posts ignored. He does have a LOT of good experience and knowledge about the CP3, but doesn't portray it as well as he could when talking filtration. I have asked his filtration recommendation before and he won't give it. We can't discount everything he says, but remember that he does deal mostly with broken CP3's, and that will jade your views.

 

[TCDiesel]

the best way to determine filter change interval is as stated above with a gauge on the cp3, when the pressure drops from 8 psi to about 2 psi under load it is time to change. the filters have many different size holes in the media the larger holes has less restriction to the flow therefore mor fuel goes through the larger holes and they clog up first forcing the fuel to be filtered through smaller holes as the process continues the filter will filter its best at the end of its life. if you change the filter before this point your throwing a 2x better filter away than the new one your putting on.

X2 Good touch tone... even 0 if the filter is designed for vacuum outlet,the Gear Pump produce 15/25hg that why Higher pressures give misleading indications and in some case push the trash Right through the Media.

 

[AH64ID]

X2 Good touch tone... even 0 if the filter is designed for vacuum outlet,the Gear Pump produce 15/25hg that why Higher pressures give misleading indications and in some case push the trash Right through the Media.

This may be the case if your looking at pressure pre-filters, but with a ~8 psi fixed pump (or whatever pressure on an aftermarket) and your watching pressure afterwords you will get an indication if the CP3 is sucking on a pressure gauge, pressure will drop well below 0 psi. The pressure can't be positive and the CP3 be doing the work (another reason to change when the pressure drops to 2-3).

 

[TCDiesel]

If you are monitoring pressure after all the filters, and just before the CP3 you CAN get a good indication of filter life. Yes the CP3 can draw a vacuum, but that will show up on a pressure gauge. If you still have good pressure then you are not plugged and sucking thru the filters. I usually tell people that if your gauge goes to 2-3 psi WOT then it's time for a new filter, or a bigger pump if your making that much hp. Bosch specs -5 to + 15 psi at the inlet of the CP3, but reading +3 is easier than - 5. This is NOT a substitute for a regular filter change interval, just an additional way to monitor the system.



Todd like to talk trash about internet hype fuel filtration systems, but the simple fact is the one filter on his truck is rated lower than any setup of anyone in this thread. He feels thru his experience that the people that rated his filter were wrong and runs it, that doesn't work for 99% of people. He also talks about internet hype systems, but has yet to mention what system(s), even thou he has been asked repeatedly. He want's to kill the snowball but the way he talks about filters doesn't do much but get his posts ignored. He does have a LOT of good experience and knowledge about the CP3, but doesn't portray it as well as he could when talking filtration. I have asked his filtration recommendation before and he won't give it. We can't discount everything he says, but remember that he does deal mostly with broken CP3's, and that will jade your views.

I don't hang My laundry On the NET (Dirty) and agian You are welcome to Call anytime... Guest and member the NET is MAYBE 3% of owner post, if the NET is the Only Place for adverting why have all Manufacturers left form open forums? They use the NET for advertising BUT are NOT willing to defend the Products when Challenge? AGAIN and AGAIN you don't need to worry about filtration 99% of the time,its the 1% you need to have the correct setup STOP trash 100% NOT filter it down to x % BC the X % will suck up your wallet. I don't mention any company I don't need the legal Hassle,as an owner I demand answers form the Manufacture and legal documents that state if it fails they will cover all damages, Show Me that warranty? all these companies do is advertise their Best Day ( Even the Vikings can beat someone on their Best day) But will have 1- 15 record:-laf So they beat 1 team let's advertise the statics how great they were on 1 Day,it's legal but does anyone think the Vikings are Great:-laf :-laf only the cheerleaders

 

[TGVET]

Fuel pressure

This ^^^^ is the main reason I just decided to change my canister fuel filter at every oil change, and change my GDP 2-micron filter every other oil change. I'd rather put money in filters than expensive engine parts.







CD

Ditto. I change my GDP 2mc and stock filters every 10k, I get the filters from my marine center at more than half the cost anywhere else. I'm a maintenance freak which has paid off in the long run.

 

[AH64ID]

There are several engine mfgr's that caution against over servicing fuel filters, as in the long run your fuel is actually dirtier with a new filter than a used one. The best a filter works is right before it's clogged enough to prevent flow.

 

[Wingate]

We monitor filtered and unfiltered fuel pressure and recommend fuel filter replacement by differential. Of course, I'm talking about much larger engines...

IMHO, fuel filters and air filters CAN be replaced too often. At one time, I was fanatical about replacing the fuel filter on my truck EVERY 5K, but anymore, I'm going to run it 15K, or "having issues", whichever comes first. I keep a spare filter under the seat, along with a cresent wrench.

 

[CKelley1]

ah64id the filter manufactures will state the same thing you just said. also as you stated the class 8 truck manuals on the air cleaners start off ( WARNING do not over service ) on the fuel filter it was not as strong but shows the engine builders are concerned about this

 

[TCDiesel]

X2 AD... If the filter Has NO bypass ,let it plug, carrier spare or 2. if you change it, and the New plugs quickly, drop the tank , if trashy clean it out,several $$$$ less then motor, and CR Injection component's. On the canister filter if it looks good put in back in and continue to run until Next service, check and replace ,if it looks good run it again,I have no problem running filters 2 years or 80K miles, or lack of performance.

 

[EDankievitch]

Your first post said that you had the in tank lift/supply pump. I have the same set up on my 05. I installed the heavy duty filtration kit (the B20 kit) back when Dodge had offered it. I also installed a fuel pressure gauage on the inlet fitting of the Cp3 pump. This location will show when the filters are starting to plug up. As soon as I see a slight drop in pressure under load, I know it's time to change. That said I've been using Metro fuels for my BioDiesel B20 blend. I've found their fuel to be very clean. I have gone as far as 25,000 miles on a set of filters with out any loss of pressure. On the other hand I have done a few trips where I had to buy fuel on the road and plugged up filters after two tanks. (Exxon fuel on I95 rest stops between Nj and Sc) So it's really where you buy your fuel as to how long your filters will last. Keep an eye on your gauages.

 

[TCDiesel]

Your first post said that you had the in tank lift/supply pump. I have the same set up on my 05. I installed the heavy duty filtration kit (the B20 kit) back when Dodge had offered it. I also installed a fuel pressure gauage on the inlet fitting of the Cp3 pump. This location will show when the filters are starting to plug up. As soon as I see a slight drop in pressure under load, I know it's time to change. That said I've been using Metro fuels for my BioDiesel B20 blend. I've found their fuel to be very clean. I have gone as far as 25,000 miles on a set of filters with out any loss of pressure. On the other hand I have done a few trips where I had to buy fuel on the road and plugged up filters after two tanks. (Exxon fuel on I95 rest stops between Nj and Sc) So it's really where you buy your fuel as to how long your filters will last. Keep an eye on your gauages.

All the extra effort paid off... Good to hear. But You do need to find out If Your filter(s) have Bypass Valves or Spring, Also IF the Bypass in the Head, Set at What PSI?

 

[STEVEBROOKS]

Appreciate all the replies so far. I too firmly believe filters can be changed too soon, resulting in less-then-best filtering and wasted $. With two filters in the line, if using only the "2-3 psi at the CP3" recommendation, I'd need to change both filters due to not knowing which one is plugged. While that's not anything too hard to live with, I'd still prefer to know which filter is the real culprit. Can anybody think of a way to tell which of the two filters to change?



Steve