davco filter--how quickly should it be getting dirty?

[Broncohauler]

What about an age limit? Our truck has what I assume are factory fuel lines from 1998, so the hoses are probably 1997 vintage or older. This truck doesn't have a Davco unit that you can see into, and beyond cutting a filter apart there is no way to monitor what's happening. Until the engine stumbles....

From my crawling around under the truck and checking stuff I've noticed that the lines are pliable still.

Everyone you talk to will give you a different opinion ,so all I can do is give you mine based on what I've heard from reputable people.

They have told me when you hit the million mile mark it's time to change out the hoses just for insurance.

A lot of times the hoses breakdown from the inside and you can't tell if they're good or bad until they fail.

also fuel hoses will begin sucking in closing down limiting the amount of fuel being supplied to the motor reducing power sometimes feel mileage.

With that said my trucks and 1997 with 1,500,000 miles and original hoses. I just had my truck serviced last night, and my Mobile mechanic recommended having his Mobile hose guy come out and make new lines and install them on site.

When I get it done I'll be happy to let you know what the original hoses look like inside and what it cost to have it done. He's also going to replace my power steering pressure line at the same time.

[Alie&Jim's Carrilite]

Thanks Bronco, I'll take you up on the pricing.....

[Jack Mayer]

What about an age limit? Our truck has what I assume are factory fuel lines from 1998, so the hoses are probably 1997 vintage or older. This truck doesn't have a Davco unit that you can see into, and beyond cutting a filter apart there is no way to monitor what's happening. Until the engine stumbles....

From my crawling around under the truck and checking stuff I've noticed that the lines are pliable still.

I'd be planning on swapping out those lines. It is not an "immediate" thing...but I'd do it sooner rather than later if you don't know how long they have been there....JMO.

[Cheyenne1]

Keep in mind what filter is getting dirty.

The priimary filter getting dirty is stuff in the tank. Bad fuel, left the cap off contamination, or about the worst we have to deal with is BIO diesel.

 

The secondary filter is moslty return fuel from the injectors. If you are not getitng the life out of the secondary that you think it should there could be more reasons than bad fuel. Look up black filter syndrom.

 

I won't go into great detail about what happens. Kind of the short story is because of the extremley high injection pressure we deal with now( 30,000 psi compared to the 4,000 psi we used to have). The injectors will carbon up in the top of the injector, as this happens the extreme amount of return fuel we have ( about 60%) as the fuel goes back through the return filter it will leave the carbon in it. Cut your filter open and see what it looks like I will garuntee it is very black.

 

I deal with this all the time. This gets bad as our trucks get higher in miles.

One thing that we do is fuel system flushes. we connect a special canister and use a flush that the truck runs on.

It works amazingly well, it improves starting, extends filter life, and the best part is extends injector life.

[roadfitter]

HI Jeffw!

 

Well I would say you have found your problem, all those "BLACK SPECKS". I have been down that road. The fuel today breaks down the old rubber in the fuel hoses and the filter is doing its job!

I have a 12.7 Detroit in my Kenworth and my truck was born (came) with only "1" filter, a Davco 382.

It is MY belief that this is the best filter for our RV use because you can see how your fuel system is doing every time you pop the hood to check the oil. Where as on the screw on type it's impossible to visually check your fuel filters. 20k miles is a reasonable amount of millage to get out of a filter. I am running a single 7 micron filter, I have been told 7 micron is comparable to the average human hair.

I have been using the Donaldson filters on my engine for 10 years now, without issue, 7 micron.

I found out this last spring, because of fuel filter issues, the filter bowl was filling up, that I had a heavier than normal % of Bio Fuel in my tanks. The easiest way to explain is that the solids in Bio Fuel begin to break down around 45*. Below this temp the fuel will look milky and can have a hard time getting threw the filter element thus filling the bowl and making the filter look like it needs changed.

However after taking the truck for a ride an bringing it up to temp (including fuel) milky looking fuel and the Davco all looked and acted as it should. Davco tech suggestion.

I can't say enough about Davco and there Tech Support. They are very helpful and if need be will hook you up with there factory tech person in KS. City.

So the first thing I would do is to change out all your fuel lines, including return hoses and clean out the Davco check valve, new ball and spring from dealer or Davco $11.00 + tax.

 

HAPPY TRAILS

roadfitter

[RogerV]

When we got out to Sturgis 2 weeks ago on our first trip I popped the hood and glanced at the Davco filter and it was up to the top with fuel and when I opened the top fill plug all the fuel ran back into the tank humm. I pulled the filter and there was at least 2" of black crud in the bottom!. I grabbed a spoon and scooped most of it out and popped the drain and cleaned the rest out with gas while keeping the center hole that goes to the final filter covered. On the inlet side there is a plastic cage with a spring and a ball that is a check valve that is not suppose to let fuel drain back into the tank.

when I looked at the little spring and it was broke and not letting the ball back into the seat, so off to the local truck dealer for a $8 service kit and we were back in business. Who knows when was the last time it was changed before I bought the truck