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Electric pump?

What is the electric pump for on the rear crossmember? Has fuel lines to it. Is it the lift pump or an assist pump? Having trouble getting coach to start, have to crank for awhile to get engine to start.

Thanks, Larry

Re: Electric pump?

Reply #1 –
Perhaps a WINN primary fuel filter/primer pump.  Superseded because of leaks, particularly on the clear plastic housing O rings.

A picture would confirm that.

Re: Electric pump?

Reply #2 –
Yes problematic if not maintained. Once I figured out orings and replaced plastic screen I genuinely like now. Also like the bleed feature and automatic water removal
Scott

Re: Electric pump?

Reply #3 –
I'm not having any leaks. In your picture it's the electic device right below the filter that I'm talking about. Should it run when the key is on?
Coach is at shop getting a new redhead put on so can't send a picture.
Larry

Re: Electric pump?

Reply #4 –
Which motor is that?

Re: Electric pump?

Reply #6 –
Thanks Brett I'll check it out. So what is that box with the fuel lines and electric going to it? The shop that has it can't get it to start after I drove it to them for the steering box and they were asking about if that electric box was the lift pump. It starts hard after it sits for awhile but usually starts.

Re: Electric pump?

Reply #7 –
Quote from: Townrestor –
Thanks Brett I'll check it out. So what is that box with the fuel lines and electric going to it? The shop that has it can't get it to start after I drove it to them for the steering box and they were asking about if that electric box was the lift pump. It starts hard after it sits for awhile but usually starts.
That is the control panel not a box. No fuel lines go to it. It purges the air and water in the filter system. Many coaches have had them removed but I, like Scott, think it is great.

Re: Electric pump?

Reply #8 –
Yes, a  good system IF (large IF) you are good with maintenance and replace O rings as needed to prevent air leaking into the fuel system.

But, it was superseded because it did require more maintenance than its replacement. Were it mine, I would buy spare O rings AND also the clear plastic housing.  Install the new one and keep the old one as a spare (with new O rings on it).

Re: Electric pump?

Reply #9 –
I have the same filter that Scott shows.  I also like it because if the pre-filter screem shows an accumulation of black flakey stuff (algea) then all of tht is prevented from getting to the other two fuel filters.  In this version you can see it, take the pre-screen filter off and clean it.  It never hurts to have a spare.  It uses two different size O-rings as well, I have a bag of both  sizes and will replace them if I remove the filter for cleaning.

Some care is required to remove and replace this filter. Some report leaks, in 11 years mine has never leaked.

The bottom of the white filter next to the pre-filter is the water separator.  It drains water when the H2O Purge button on the panel to the right of the one Scott circled is pushed.  If you push the Air Purge button, fuel is pumped through the filters to get rid of any air.

If the fuel level in the pre-filter is low, try pressing the air purge. Let it run through its cycle, maybe press it again.  A sluggish start on the ISM11 is often fuel related.  If your engine is not turning over very fast then clean all of the start battery connections and the connections at the two studs on the side of the battery.

I redid my start battery connections this summer and my engine turns over and starts much faster now.
Start Battery Wiring Modification

Re: Electric pump?

Reply #10 –
I have the same system and before I changed my fuel lines I would push the air
purge button when it was hard to start. That would get it going.

Re: Electric pump?

Reply #11 –
So are you saying that is the purge pump that is in question? Only works when purge button is pushed?

Re: Electric pump?

Reply #12 –
Yes, the air purge pump button.

Re: Electric pump?

Reply #13 –
Yes if next to the filter. The box on the right hitch rail is the electric controller for the radiator fans. On the center control panel to the left of the stop start switch's there is also  a water in fuel function I added a switchable ground which opens solenoid and dribbles fuel out. Proves it works. I operate about once a year.
Scott

Re: Electric pump?

Reply #14 –
Thanks Roger! At least now I know it should work when the button is pushed. I will check my o-rings when I get the coach back.
Now I am confused. Scott says it's the controller for the fans. If so where is the purge pump?
Larry

Re: Electric pump?

Reply #15 –
Purge pump on the filter and screen assembly. Fan controller on right rear hitch with lines going to it. Three

Re: Electric pump?

Reply #16 –
If the fuel purge button and pump fail to function  and the air purge pump will still works, can this cause a fuel flow problem? Jim

2002 U320

With the limp mode problem
For my 450 HP M-11

Re: Electric pump?

Reply #17 –
Some people still like that old system and it works well for them. It was problematic (particularly in colder temperatures) for me and so I replaced it with the current system from Parker and I've been well-pleased with the results for the past several years.

https://ph.parker.com/us/en/spin-on-filter-pump-systems/790r30-12v-dc-pump

The Racor 700 Series Fuel Filter Water Separator is a two-stage filtration and re-priming system that's designed for use in heavy-duty diesel applications. The assembly comes equipped with a state-of-the-art integrated fuel pump, which allows for easy priming and simplified service by eliminating messy filter pre-filling and engine hard starting.

Re: Electric pump?

Reply #18 –
Quote from: Jim Frerichs –
If the fuel purge button and pump fail to function  and the air purge pump will still works, can this cause a fuel flow problem? Jim

2002 U320

With the limp mode problem
For my 450 HP M-11
They are the same pump, switch. The purge pump is only to get the excess air out so the primary fuel high pressure pump can function. During normal operation the hi pressure pump draws fuel threw the inactive purge pump, secondary filter and the primary including all the lines from the tank. Some small air leaks can be managed but reduce the output pressure and noticeable during start by not attaining needed hi pressure. Excess fuel is returned to the tank with the air. Also used for cooling the ECM (Chilling plate) during return.
Scott

Re: Electric pump?

Reply #19 –
So this is were I will eventually end up. I do currently see a vacuum being made by my fuel injection pump and having a dedicated lift pump makes sense to me and any added gains if they do happen would be nice also. Just having positive pressure would eliminate any possible air leaks after the FASS. Fuel is much larger than air and is not as susceptible to leaks as air IMO
Scott

WHAT IS FASS FUEL AIR SEPARATION SYSTEM?
FASS stands for Fuel Air Separation System and is a combination diesel fuel lift pump and fuel filtration system that is designed to improve your diesel truck's fuel mileage, engine performance and extend the life of your diesel injection system. Our diesel fuel pump and diesel fuel filters are made in America in order to provide complete customer satisfaction. Regardless of the vehicle you drive, and how you power your life, FASS diesel fuel systems provide the cleanest fuel in order to extend the life of your favorite truck. For more information contact your local FASS fuel system dealers today!

What is Fass – Fassride