Community Forums

lakebuster · 04-06-2018, 08:02 PM

Changed out my own fuel filters on Cummins 8.9L engine. It came with a manual plunger to purge air out of the fuel lines. Now have a different MH that is now 1 year old. It has the isx15, I have the two fuel filters but see no plunger to purge air from fuel system. Has anyone changed the fuel filters on a 2017 isx15. I have googled and YouTube but only shows how it is done on a 18 wheeler. Thanks for any input!

irishguy · 04-06-2018, 10:15 PM

I've changed out both filters on our ISL a number of times. I pre-fill both filters through the small holes while plugging off the large center hole. I then cycle the ignition a few times and fire it up.

Irishguy

WinnieView · 04-06-2018, 10:22 PM

We have a plunger now but didn't previously and as mentioned we would cycle the ignition several times, we didn't pre-fill.

Car1 · 04-07-2018, 07:01 AM

Quote:

Originally Posted by lakebuster

Changed out my own fuel filters on Cummins 8.9L engine. It came with a manual plunger to purge air out of the fuel lines. Now have a different MH that is now 1 year old. It has the isx15, I have the two fuel filters but see no plunger to purge air from fuel system. Has anyone changed the fuel filters on a 2017 isx15. I have googled and YouTube but only shows how it is done on a 18 wheeler. Thanks for any input!

I have do what "Irishguy" does. I have a container of fresh diesel, I have a small funnel that I use to block the center hole of both filters and prefill them. On my ISX I have shutoffs on both sides of both filters, which keeps air infiltration to a minimum. Either way, fill both filters and install. On my primary filer housing, there is a vent screw that I loosen, I then cycle the ignition about six times leaving the ignition "ON" for about 20 seconds. While you do that, a second person could watch for fuel or air coming out of that vent. Close that vent and try starting the coach. I also had to remove the lower access panel on my American Eagle to make servicing the filters much easier. I hope this may help you.

Fred '12 American Eagle

Old Scout · 04-07-2018, 07:20 AM

...seems to vary my coach manufacturer but some have vents, some have turn-off valves, some have remotely located filters, and some don't. All late model Cummins have left pumps to purge the air/recir fuel back to main tank. 15 years of changing filters on my ISL and never pre-filled fuel filter [only have one] and never had an issue [pre-fill oil filter--yes; fuel filter--no]. Getting a pre-filled filter screwed on the secondary filter located on side of some engines must be a PITA.

lakebuster · 04-10-2018, 12:09 AM

Both Primary with clear water bowl and sensors and secondary filters have block valves. Did not see vent screws on top. Filters are easy to access on Spartan K3 chassis. Called cummins they said to not prefill filters, but after change out turn key on for 20 seconds then off and repeat 2 more times as someone stated the lift pump will fill fuel system with diesel. Will find out this weekend. Also dreading changing out that massive air filter. The 1st time was a bugger on our other MH. But using silicone spray it was easy to reinstall.

RustyTools · 04-10-2018, 01:40 PM

Ditto what irishguy said.

Tried it the 'correct way' by replacing them empty, but ran the start batteries down twice. Fired right up when filled first.

Old Scout · 04-10-2018, 04:48 PM

"Rusty"...if you "ran the starter bats down twice" by simply cycling the lift pump and didn't trying to actually start/crank the engine--you are doing it wrong....Either way seems to work--I "prefer" to avoid contamination so I install my single filter dry...I open the vent and cycle the pump.....to each their own????

RustyTools · 04-11-2018, 06:18 AM

@ Old Scout...

I followed the 'approved' method several times with both coaches, always came up with the same result - low battery(ies). And that's turning the key to 'RUN' (not START) and waiting... and waiting... and waiting... and... So I'd try cranking it, figuring I might get better results. No joy either.

It is possible that the lift pumps are/were weak and wasn't giving enough fuel. Hence I asked in another thread about how much fuel should the lift pump deliver. If mine pumps less than what it's supposed-to, then I have a place to begin. otherwise, I'll just be real careful when pre-filling.