Community Forums

Mlfiedler · 07-01-2020, 10:58 PM

Have been following the couple threads about the FASS fuel pump and filter upgrade, and finally began to recognize how ignorant I’ve been. Started by looking up specs on the filters my rig came with. Turns out, the Fleetguard FS1022, and the FS1242 are both Fuel/Water Separators.

Early on, (with the fuel in the coach when I bought it,) we had some very rough accelerations, and finally she refused to come up to hiway speed. Sure enough, filters full of algae. Put new filters on, and continued the trip home. So I’ve learned about algaecide, and storing the coach with full fuel tank, and how bad any crud that makes it into the injector pump is going to be.

And each time I’ve had Freightliner service the coach, they have put on a pair of new filters. But in scoping out the FASS system, I learned the service life for those filters can be a good bit longer than a year. (At least with the kind of miles we have been putting on, 6,000 or so a year.)

Trying to cultivate some understanding, I found a funky video on YouTube [“How to Drain Water from a Fuel Filter (Diesel-RV)”] about draining the water from these things. I was shocked to hear the presenter say, “This is something that should be done every time you fill up your fuel tank . . .”

YIKES! Three years of driving, and I hadn’t done it once! (Freightliner never told me if they found a filter full of water! They also never offered any assessment of how I was treating my coach, though I did ask if there were things I needed to be doing, or watching out for.)

Is this Standard Operating Procedure? How often do I need to be draining these separators? Just drained them both into a glass jar, but found no water accumulated in either?

Slightly different issue: since both the FS1022 and FS1242 are 10 micron rated, is there a different pairing that would offer better protection? If the FS1242is the pre-filter, would I be ahead to plug the WIF wire into the connection on that unit? It seems they both have a connection, but I have only one wire. Is it common to have two separator units?

Man it was bliss not being bothered by how little I know!

**CountryFit** · 07-01-2020, 11:21 PM

Not sure if you have an ISC 350, as yours is one year newer than mine. I use FS1022 and FS1212, latter has a 20 micron rating and isn't a water separator.

I normally drain it every 5000 miles or half a year. Not sure it's right but there has been no ill-effects.

geordi · 07-01-2020, 11:41 PM

Mine is a couple years newer than yours, and I recently did the FASS install. A couple observations:

With old fuel on board and a tank that probably was / is producing a decent amount of scale... Even on a perfectly clean tank, your engine is being asked to SUCK the fuel from 40 feet away and through at least one of those filters! The second filter MAY or MAY NOT be under pressure, I strongly suspect on mine that the gear pump / injection pump was pulling through both filters. This is a crazy design, I don't know why they would do that.

Before installing the pump, I was getting an occasional warning light on the dash when on the highway, and a code related to fuel pressure. But the coach felt like it was struggling to accelerate.

Since installation, while the performance is not what you would get from a Tesla or a drag racer.... It IS able to smoothly accelerate up to highway speed and doesn't seem to be struggling at all anymore.

I probably went overkill based on the advice of the guys at FASS and got the TS165G kit, which is 165 gallons per hour - 99% of which will be returned to the tank. BUT the price difference didn't seem to be that much, and the installation was the same anyway. I'm OK with it. Since then, no codes and what feels like a happy engine. Since I expect my tank still has some detritus in it, for right now I'm using a much larger primary filter with the FASS 2 micron secondary - the factory second filter is now just riding the engine for the fun of it, I doubt I will ever change it again.

FYI: I've had diesels exclusively for over 20 years now... And I've never drained the water separator in any of them, certainly not at every fuel stop! That's just comedy. High volume stations like truck stops pump through 50,000 gallons PER DAY so there's little chance for the fuel to accumulate any water in it!

TR4 · 07-02-2020, 07:35 AM

I believe the FS1242 has a 20 micron rating. With my Fass system I’ve gone three years on my filters with minimal loss of fuel pressure. I’ve been lucky and have never seen water in the bowls and have never drained them.

Bill

Ljwt330 · 07-02-2020, 09:18 AM

Agree with others regarding draining the water separator.

My first coach, on a Freightliner chassis, had a sticker on the fuel door that said to drain the fuel filter after each fill up. Never did it after talking to several diesel owners, and never had a problem.

However, be aware that water can enter the fuel and stay alert for any signs of dropping engine performance. Outside of drawing water into the tank from a tainted fuel stop, long storage with a low level of fuel in the tank can lead to condensation which will deposit moisture into the fuel. That process, of course, takes time and variations in temperature and humidity, not unlike the conditions that produce algae.

Alpine36 · 07-02-2020, 09:34 AM

Quote:

Originally Posted by geordi

Mine is a couple years newer than yours, and I recently did the FASS install. A couple observations:

With old fuel on board and a tank that probably was / is producing a decent amount of scale... Even on a perfectly clean tank, your engine is being asked to SUCK the fuel from 40 feet away and through at least one of those filters! The second filter MAY or MAY NOT be under pressure, I strongly suspect on mine that the gear pump / injection pump was pulling through both filters. This is a crazy design, I don't know why they would do that.

Before installing the pump, I was getting an occasional warning light on the dash when on the highway, and a code related to fuel pressure. But the coach felt like it was struggling to accelerate.

Since installation, while the performance is not what you would get from a Tesla or a drag racer.... It IS able to smoothly accelerate up to highway speed and doesn't seem to be struggling at all anymore.

I probably went overkill based on the advice of the guys at FASS and got the TS165G kit, which is 165 gallons per hour - 99% of which will be returned to the tank. BUT the price difference didn't seem to be that much, and the installation was the same anyway. I'm OK with it. Since then, no codes and what feels like a happy engine. Since I expect my tank still has some detritus in it, for right now I'm using a much larger primary filter with the FASS 2 micron secondary - the factory second filter is now just riding the engine for the fun of it, I doubt I will ever change it again.

FYI: I've had diesels exclusively for over 20 years now... And I've never drained the water separator in any of them, certainly not at every fuel stop! That's just comedy. High volume stations like truck stops pump through 50,000 gallons PER DAY so there's little chance for the fuel to accumulate any water in it!

X2

Install a FASS or AirDog system, you won't be sorry.
My results mirror what geordi said, and yes I left the oem FS1022 along for the ride.

dons2346 · 07-02-2020, 11:06 AM

In the 180,000+ miles of driving I have never seen any water in the bowl

Milford 47 · 07-02-2020, 12:33 PM

I have never seen two water separators on any diesel in 50 plus years of owning Diesel engines in tractors, trucks, and all kinds of equipment

Also the final filter should be a much finer micron to protect the injectors

Something is really wrong with that set up but if you managed this long, what the heck

I would never leave it like that but again just years of experience talking

TR4 · 07-02-2020, 06:59 PM

Quote:

Originally Posted by Milford 47

Also the final filter should be a much finer micron to protect the injectors

Something is really wrong with that set up but if you managed this long, what the heck

I would never leave it like that but again just years of experience talking

A ten micron secondary filter is what Cummins recommends for my CAPS injection pump. These pumps already have a problem pulling fuel from the tank through two filters. Your only asking for problems installing a smaller micron rated secondary filter. Now if you install an aftermarket lift pump that runs all the time, as Alpine36 recommend, you might be able to get away with it. I run an FS1022 as well.

Bill

geordi · 07-03-2020, 12:39 AM

The FASS system is a pressurized lift pump and pulls the fuel from the tank with suction through the first (IIRC 20 micron) filter, then uses pressure to push fuel through a 2 micron filter and water separator. From there it is pressurized to the CAPS injection pump, passing through the original factory 10 micron with nothing remaining to be trapped by that 10 micron filter.

The only thing that matters is that the injection pump is receiving all the fuel it wants without having to struggle to get it.

Milford 47 · 07-03-2020, 08:19 AM

Quote:

Originally Posted by TR4

A ten micron secondary filter is what Cummins recommends for my CAPS injection pump. These pumps already have a problem pulling fuel from the tank through two filters. Your only asking for problems installing a smaller micron rated secondary filter. Now if you install an aftermarket lift pump that runs all the time, as Alpine36 recommend, you might be able to get away with it. I run an FS1022 as well.

Bill

10 might be marginal but perhaps doable with good fuel

20 as noted is just too large fo a final

Newer engines definitely have lower micron size for fuel system protection

Eddvel · 07-06-2020, 06:04 PM

1-FS1242 primary. 20microns
FS1242B (W/plastic sight on bottom)
Fill with diesel first
( On outer holes )

2- FS1022 secondary 10microns
is dry , don’t fill w/ diesel
(Use engine pre start 2/3 times)
Before starting engine
Have been using these filters 20 years.
330ISC CUMMINS.

funjnt · 07-09-2020, 05:22 AM

Boy have I been down this road... So when we bought our new to us allure it already had fuel filters installed, good thing yes. So on our trip home and on occasion, we would get the bucking and hesitation of a bad injection pump. Not good. Each time it would do this I would change the fuel filters and it was fine. I kept replacing the filters with the ones on it when we got it or equivalent numbers. This turns out to be incorrect, the filters I had. Turns out they some how got down to a 2 or 5 micron filter and that was too fine filter media for the caps to pull fuel through. I am now on my second set of the above fleetguard filters and haven't had it buck or hesitate at all. Whew. I hope no damage was done till now.

As far as the water separator, I have never seen water in mine either. I also own many diesels and some do get water but I think that is my off road fuel supplier. Draining filter can't hurt.

I would keep with the original filter numbers and don't increase the micron filtration thinking you can have cleaner fuel. Our systems are older and don't have the tight clearances the new ones do. Stick to what is recommended.

I still do want to add the fass pump also...

Roy1 · 07-09-2020, 01:13 PM

I use the factory recommended filters and added the fass pump similar to the way Bill did (TR4) I can definitely feel the engine pulling stronger on a steep mountain pass it was in my opinion worth the expense and manual labor on my part. Adding a dash fuel,boost and pyrometer gages were nice too.