Can I completely *remove* the OEM fuel filter from the system?

[johnny2can]

I'm looking forward to my first fuel filter change... NOT! I am strongly considering installing a simpler (and better) fuel filter setup (like Kennedy's) (http://www.kennedydiesel.com/detail.cfm?ID=241).

Everytime I look at these better filters I wonder to myself "Why would anyone keep the original filter in the system"? It's not as good as the new filter you're putting in (2 micron vs what, 10 micron?), and it still needs to be changed along with the better one... other than the initial work to remove/bypass it, I'm thinkin' I'd be a lot better off without it.

Thoughts? Experiences? Warnings? Words of wisdom to bring me in from the puckerbrush?

-John

[eracers999]

Hi;
What year of a truck are we talking about??

D Max, 6.5 :confused:

Kent

[CareyWeber]

If you have any warrenty left then I'd say its a bad idea.

I have considered it on my truck, but its a 97 with +186K miles on it. I doubt I'll ever do it though.

Carey

[Hubert]

Someone else recently had a thread going on this. Depends on expected weather temps too. Keep in mind the OEM filter set up does have a heater element too. I don't know about your aftermarket one.

If you want to get technical read another reply but I think the temp is important for proper diesel viscosity for the IP to control precise amount of fuel delivery.

[Turbine Doc]

John since you have a 6.5 keep the factory and add a RACOR on the frame pre lift pump 20 or 10 micron rated will make the factory more efficient.

[ 12-22-2004, 09:33 AM: Message edited by: tbogemirep ]

[ucdavis]

IIRC, Stanadyne or maybe GM commented on 2 micron filtration being too restrictive for proper operation of the lift pump. If you can get, by using a higher gpm lift pump, or just by proving thru measurement @ high fuel demand (gotta be in a run condition w/foot on the floor) that you get ~6psi fuel pressure @ Injection Pump input, any filter before the IP should be OK. If you can't get in that vicinity, you will likely have fuel delivery trouble @ high fuel demand when the new filter is getting clogged.
Keep in mind the heater function of the OEM unit that corrects fuel gelling @ very low ambient temps; if you need that, you will also need to put a fuel heater in line.

[Turbine Doc]

Factory 6.5 filter is 5 micron according to WIX, & Stanadyne tech group email post I got once. IIRC 2 micron is what DMAX uses.

According to RACOR site & call to tech guy I called, optimal rig would be 2 mic final, 10 or 20 intermediate, and 30 mic primary. Would not put that in writing though as did not want to be on paper if warranty issue came up with GM.

A lack funds and real estate to put in all those filters, I run the factory 5 mic with 20 mic on the frame pre lift pump with DP switches to alert when filter gets blocked, 1.5 years that way 25K mi no filter blocked alarms yet.

[ 12-22-2004, 09:40 AM: Message edited by: tbogemirep ]

[eracers999]

Mine is comming out, if you have adequate filtration away from the heat then there is no reasone to have the fuel oven filter on the intake.

Kent

[BuffaloGuy]

My IP just got rebuilt after about 110,000 miles. The report from the rebuilder was that it was in surprisingly good shape. Sounds to me like the factory filter set-up worked just fine for my mechanical IP.

The older pumps are much more forgiving than the new ultra high-pressure systems.

I do have a gauge reading fuel pressure post filter. It has showed me when my lift pump quit about 10k ago. Pretty handy. It also lets me know when the filter is getting full. I found that the filters seem to last quite a lot longer than I expected (25K+ with the fuel I've been using).

Another added benefit of the fuel pressure gauge is that it works like a mileage gauge. I can look at the pressure and tell how hard the motor is working and I have a rough scale that converts the pressure to MPG.

It helps me keep my foot out of it!

[johnny2can]

Thanks, everyone, great info!

Kent, it's a '97 (see? I put it in my sig now!). Main reason I want to pull mine out is it looks to be a pain to climb on top of the engine every six months... easier to just drop a cartridge off the bottom of the truck...

I'm planning on putting a 30 micron heated Racor pre-lift pump, which should take care of any gelling issues.

tbogemirep, can you give me a link to the dp switches you use? I'm very interested in a similar setup.

Thanks again, all!

[johnny2can]

Oh, and Buffalo Guy... what did you use for a sending unit (I'm assuming it's electrical) or is there a kit designed for the pressures we're expecting? Thanks.

[Turbine Doc]

Go here http://www.parker.com/racor/pdf/Section01.pdf in accessories page 84 you see description of vac switch Racor pn RK20163 set for 7" Hg, I verified for that setting by my vacuum gauge. If it were me Id keep the factory filter it's a finer filter and makes a great final, crappy all in one rating, what clogs them so fast is all in one, it is getting ALL trash in fuel large and small particulate, using a large body RACOR as a primary will go a long way to keeping the factory filter clean.

Spend some time on RACOR site reading up what micron ratings are all about basically coarse 30mic, med 20-10 mic, and fine 5 or less mic

I use a 20 micron in my primary so far at 25 K I've not needed to change on engine filter yet, I pulled it at 10K then 15K almost clean as new, now leaving it up to the vac switch to tell me when I NEED to change the filt.

Factory filter is part of PCM controlled fuel management, there is a heater and a water sensor in there. Adding those to the RACOR drives the cost up significantly, unless you are running in a LOT of cold weather I'd save some $$$ and just use the factory equipment for that. Mine does not have a heater other than GM provided one, and I've not missed not having one, I'd try without it can be added later if you feel the need for one.

I doubt also that gelling will be much of a problem unless really cold, as a preventative I'd recommend a quality additive I use FPPF total power per Kennedy recommendations, it has never let me down, his case lot price is pretty competative.

As fuels get diddled with more and more to make tree huggers feel comfortable; using quality additive that adds anti water, adds cetane, anti gel, and lubricity. FPPF is but one of many good ones out there and cheap long term insurance IMO.

[CareyWeber]

I have a Racor 445 with a 30 micron filter pre-liftpump and I have noticed that my factory filter stays much cleaner that it did when it was my only filter. I have read that preliftpump filters are best for seperating water from fuel.

I also run a heater on my 445 to avoid it ever plugging in cold weather.

I plan to install Racor's vac sensor and a pressure gage to monitor my filters. Filter prices have gotten to high to just replace every six months.

If you don't want to climb to reach the stock filter then maybe just move the stock filter to a better location IIRC someone posted about doing that once I think that is the best thing to do after adding a preliftpump filter.

Carey

[BuffaloGuy]

For my fuel pressure gauge I have an old mechanical SW that was new in the box. I got it off EBay for $20 if I remember right.

I have it plumbed into the cab with 1/8" soft copper tubing. I sleeved the copper in rubber fuel line and put a hose clamp on it right next to the gauge.

If it should leak it would leak into the sleeve and run out under the hood and not in the cab. I have the end of the sleeve in an easy to see spot near the firewall so when I check under the hood a quick glance is all it takes.

Max pressure is about 12 psi. When under heavy load it will run at about 3 psi.

[ucdavis]

Buffalo- That's interesting that you get a 9psi differential, since Stanadyne (or maybe GM) says 6psi off lift pump when idling is OK. That'd mean the IP is running on -3psi @ heavy load & WOT if you start w/6. I always thought a few more psi from the lift pump would be a good idea.
Is your fuel delivery stock otherwise? And what's a "heavy load?"

[johnny2can]

Ok, my plan now is to keep the OEM but move it (thanks, Carey, I never even considered it! found a post here (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=004604) ), to get a pre-lift 20 micron without a heater (I'm in the Pacific NW, where it rarely gets below +32), and to monitor my pressures with a guage and switches...

Last question before I get busy... tbogemirep, how many switches do you use and where? and thanks for the link.

Merry Christmas and Happy New Year y'all!

[Turbine Doc]

2 switches 1 at each filter outlet; I put in 2 tees for outlet of engine filter 1 fitting for the switch and the other for the gauge

[BuffaloGuy]

I guess I wasn't clear. The max. pressure that the system actually makes on my truck is about 12 psi. The lowest it reads is about 3 psi.

Heavy load would be pulling 20,000 lbs.

[rjwest]

I am running a 2 micron Pre filter.No heater(Florida).
Also a 2nd in line Lift pump ( emergency use ).:

Also a Fuel pressure gage. 1 of the better mod's. Any problems are instantly analyed to,
High press ( IP/controls) or low pressure.

Pressure is 12 psi ign on. Idle 9 psi.

At Load at 65 MPH 6 psi.


Drops with additiuonal " go pedal " Sometimes to " 0" on a STEEP hill, ( Turn on aux lift pump)
and pressure comes back up).


Replace Aux filter 2x per year ( 10K miles.)
Main filter 1x per year, about 20K Miles..

[CareyWeber]

Originally posted by johnny2can:
Ok, my plan now is to keep the OEM but move it (thanks, Carey, I never even considered it! found a post here (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=004604) ), to get a pre-lift 20 micron without a heater (I'm in the Pacific NW, where it rarely gets below +32), and to monitor my pressures with a guage and switches...

Last question before I get busy... tbogemirep, how many switches do you use and where? and thanks for the link.

Merry Christmas and Happy New Year y'all! I've thought it was a good idea, but so far for me its been an idea'er (you know something that ought to get done, but most likely ain't gonna get done). ;)

I would encourage you to get a heater though. I feel it it alomost as important in warmer areas as it is in cold. Colder regions keep a better handle on running winter fuel to reduce fuel gelling issues warmer areas don't. The change periods from warm to cold are when the gelling will bite you. Do you ever drive over the pass on I-90 Squamish (Spelling is an Idea'er for me too) it can get cold there. I drove a diesel Scout for four of the five years I was stationed in Alaska it didn't have a fuel heater in it, but they always have good fuel in Alaska. I also think the fuel there was drier (had a lower wax content).

Carey

[johnny2can]

Originally posted by CareyWeber:
I would encourage you to get a heater though. I feel it it almost as important in warmer areas as it is in cold. Colder regions keep a better handle on running winter fuel to reduce fuel gelling issues warmer areas don't. The change periods from warm to cold are when the gelling will bite you. Do you ever drive over the pass on I-90 Squamish (Spelling is an Idea'er for me too) it can get cold there.heh, heh, heh... ok, good point. The whole reason I got the rig was was to park it at Snoqualmie Pass ( Squamish is in BC near Whistler... may be going there soon, though... ;) ) with a camper in the back while skiing... would be cheap insurance against getting stuck just 'cuz I had "Seattle's Best" in it... thanks, Carey.

Thanks, Tim, for the switch locations... makes sense.