DIY Fuel filter questions

[don8ch]

In preparation for upcoming trip I obtained new fuel filter and fuel/water separator. Engine is Cummins ISB 340HP/660 Torque with post-2007 DPF.

1.) Fuel/water separator. I thought that I would drain the fuel from the bowl by opening the water drain until the filter emptied. Well fuel continued to drain into my tray until the quantity far exceeded the amount that the filter and bowl could possibly hold. I closed the valve and decided to restart the engine. Used the off/on proceedure about 6 times and started right up. Question: Will fuel continue to run out the entire time I have this filter off? My tray is only about 4 quarts and I'm concerned about overflowing it.

2.) While waiting for answer to 1. I decided to change the other (2 micron) filter. It was a real chore to get it loosened up but off and on, no problem. It also dripped fuel slowly the whole time the filter was off but no big deal. When I went to restart after the change I did the on/off sequence 6 times and tried to start. No start. Several more times - nope. I wasn't hitting the starter, just on for 20-30 seconds then off and repeat. Eventually (after 45 minutes of trying and cranking the starter for up to 15 seconds from time to time, it started. Whew! Are you supposed to hit the starter enough for a quick turn each time or just on/off?

Your help is appreciated.
Don

[Skip426]

Sounds like you had a syphon going from the fuel tank, try removing the fuel filler cap before you start. May help.Otherwise you have to be quick.
On Dodge Cummins, the lift pump cycle, was 18 sec. from key on, twice. After the second time the pump would not cycle until the starter was bumped , 2 sec was enough to re-start the cycle.
Also it may be time to have the lift pump tested for pressure/volume. Many posts on these failing .

[Gary RVRoamer]

It is not unusual for fuel to run while you change the primary. It may even be located below the level of the fuel in the tank. Just spin the old one off and the new one on and you won't lose more than a few ounces plus whatever is in the filter canister.

No, you don't crank the engine each time you cycle the key. It sometimes takes awhile especially since you had the primary drained too. Just because it started after you closed the primary drain does not mean there was no air in the fuel line. It may have been running on what was left on the lines. I've seen that happen before - the engine runs a minute or two and then quits and you have to re-prime.

Some people fill the secondary filter with fuel before installing - it shortens the process. You just have to be very, very careful to filter the fuel so there is no chance of dirt getting in at that point, where the next stop is the injector pump and the injectors, both very sensitive to the slightest spec of dirt or fuzz.

[The Danes Are Coming]

A couple of years ago I went through the same starting problems when replacing my fuel filters, and I contacted Cummins for specific advice. Here is what I was told:

In general you shouldn't pre-fill any of the filters. You can however pre-fill the water separator filter should you so wish, BUT..... you must fill the filter through the small holes that forms a circle around the perimeter only. This way the fuel will get filtered before it proceeds to the next filter. With a pre-filled filter you will not have any problems re-starting.

When restarting after filter change, you should turn ignition on (no cranking) and leave on for about 30 seconds. Turn ignition off. Repeat process - I normally do this 10 times.

Now turn ignition on and keep cranking for up to 30 seconds. Do continue the full 30 seconds with stopping (unless the engine starts of course). After 30 seconds - stop. You can repeat this 1 time only after a few minutes. If I hasn't started you will need to wait for the starter to cool off before trying again. Failing this you may burn your starter out.

Now here it becomes interesting:

I have just come from Speedco, who, as part of an oil change, changed both fuel filters. I saw them bringing the 2 filters up to my coach and both filters was pre-filled to the brim. I challenged them on this and the reply was: "Cummins don't know what they are talking about. We have done this always and if we don't do it we will never get the engines started again". You can bet your bottom dollar that this in fact IS normal practice at Peterbuilt, Freightliner and all other similar maintenance places, because they haven't got time to mess with engines that won't start or runs the starter battery's dry.

I will still go to Speedco for oilchange and lube, but next time I will ask them not to install the new fuel filters. I just want these filters handed over and I will then change them my self.

[The Danes Are Coming]

I have written to Speedco asking them for their view on pre-filling fuel filters. Here is their reply:

Thanks for contacting us regarding the pre-filling or priming of Fleetguard fuel filters. As a practice, we do pre-fill all fuel filters, including Fleetguard fuel filters. We install 30,000 to 50,000 fuel filters a month and we have never had a customer experience an issue due to this practice. However, we have had numerous instances with Cummins customer's vehicles losing prime from failing to pre-fill the fuel filter.

While it is our practice to pre-fill, if you do not wish to have that done on your vehicle, you can let the service writer know this when you arrive and our personnel should follow your wishes.

I find this interesting since Cummins do not recommend this practice. Having said this, I do appreciate the point about "losing prime". This is definitely a problem when replacing filters.

[Doc Mark]

I just replaced my Fleetguard filter (single, I don't have 2) and just before beginning I called Cummins. I asked for the procedure to use and was told to pre-fill, pouring the raw fuel around the circumference of the filter top - NOT DOWN THE CENTER PIPE. I used a paper cup to make a funnel and slowly did as told. It is tedious but doable.

When I took off the old filter, about 2 cups of fuel ran out of the line. I lubed the gasket with fresh diesel and pulled off the old circular gasket around the center tube and then double checked it. Lo & behold, there were 2 gaskets on the pipe. I'll have that discussion with Cummins Power South when I get home.

Started the engine (no turning key off/on) and she fired right off. After a minute or so it started to lug and white smoke came out of the exhaust. I just kept her running and it smoothed out about 45 seconds later.

I am now wondering of the lack of power on hills as we ran up the coast this spring was due to the second circular gasket not allowing the outer gasket to firmly seat. Thereby allowing some air into the equation. I did notice that I was smoking more on the trip up than I am used to seeing.

Any thoughts? Do I need to start anew topic? I don't mean to hijack this one.

Mark

[Skip426]

Mark, the filters on a Cummins engine are pressurized by the lift pump, multiple gaskets on the threads would have resulted in a leak at the outer gasket, if any thing, provided of course the lift pump is doing it's job. JMHO, sounds like your due to (at the very least )have the lift pump pressure and volume checked.

[J Walker]

Quote:

Originally Posted by The Danes Are Coming I have written to Speedco asking them for their view on pre-filling fuel filters. Here is their reply: Thanks for contacting us regarding the pre-filling or priming of Fleetguard fuel filters. As a practice, we do pre-fill all fuel filters, including Fleetguard fuel filters. We install 30,000 to 50,000 fuel filters a month and we have never had a customer experience an issue due to this practice. However, we have had numerous instances with Cummins customer's vehicles losing prime from failing to pre-fill the fuel filter. While it is our practice to pre-fill, if you do not wish to have that done on your vehicle, you can let the service writer know this when you arrive and our personnel should follow your wishes. I find this interesting since Cummins do not recommend this practice. Having said this, I do appreciate the point about "losing prime". This is definitely a problem when replacing filters.

Interesting. I had a main fuel filter canister replaced under warranty and they pre-filled it before starting. I asked about that and they and they said that they were pre-filling with filtered fuel. They went ahead and the engine started with no later problems. I still think that they used unfiltered fuel and were pre-filling to speed up their work. If you have problems later it is not their concern. Cummins is the one to listen to and follow as closely as possible.

[1ciderdog]

At a Camp Freightliner session it was suggested to remove the fuel filler cap (gas cap) before removing the fuel filter(s) to help reduce the amount of pressure in the system.
Safe Travels
Bob

[Perry White]

If your worried about how the filters are changed, do it yourself. It isn't that hard.

[The Danes Are Coming]

If Speedco would sell the oil change and lube without supplying and installing the fuel filters, this is what I would buy.

If you ask for this they will accomodate you and give you a $5 discount per filter which really makes no sense at all since the primary filter on my MH is around $30 to $35 to buy (not including shipping if applicable).

[HD4Mark]

We went through the same hard to start after replacing the fuel filters so here is what we do. Loosen the filter but don't remove so it is ready. Using a gallon fuel can with fresh diesel we pre-fill the new filter by sticking my thumb in the center hole then DW carefully fills it pouring into the small outer holes to filter. I lube the gasket with a little bit of motor oil not fuel. I'm pretty sure the little pictures on Fleetguard filters portray oil on the gasket not fuel. When this is all ready spin off the old one and spin on the new so not much fuel leaks out. Then you will have to do the key on/key off dance approximately 0 to 1 times.

BTW a friend of ours that works for a Detroit Diesel shop told us when we told him we carry spare fuel filters "you better carry some fuel to prime them". I imagine any shop will prime those great big filters because they don't have time to screw around with turning the key on/off.

[JBDISCOVERY]

Question to all:
How expensive is it to have SPEEDCO change the filters and fulids? I have done all my changes by myself. On the road now and do not have a convenient place to change at this time.
Thanks.
JB

[The Danes Are Coming]

Here is a link to Speedco's price menu.