When I got the coach out of storage last friday it started right up, ran 4 or 5 minutes, then stopped. I purged the air 3 times, then it started, and I brought it home, no problem. Started it up yesterday to air up, ran fine. (Generator started and ran fine each time, and is running now.) The 'water purge' has never worked that I can see. Coach is at home in my driveway. Tank is full - filled up with 60 gallons about 6 weeks back.
When I run the purge I can see fuel pull through the clear filter and the level changes. Is the clear filter a prefilter to the large filter, or an after filter?
I have the original system with the clear filter and a Racor S3230 with the spin on bottom. I have a replacement original clear filter.
Should I start by just replacing the clear filter or do both? I expect I can get a filter from Napa, or drive across town to Cummins and pick one up there.
Dave,
The clear filter is a pre-filter to the S3230. Note that when you replace the pre-filter, there are two o-rings that are included on the ends, but there are also two o-rings that are inside the metal fittings at the ends that are not included (.612 ID x .103 dia #114). Both sets should be replaced to prevent air leaks.
When you run the air purge, make sure to vent the air through the schrader valve on the top right until you see fuel. The water purge feature only works if the control box detects water in the fuel and the light is on.
I have replaced my clear filter but have received recommendations on the forum to replace the whole assembly with a Racor 790R30 for about $260.
Chris
Which fuel filter/purge pump do you have?
The 1995 U320 came with a Winn unit with a clear pre-filter screen in a plastic housing where the fuel enters the top and exits the bottom - these let air in as they age because the necks at the top and bottom get narrower from "O" ring pressure. I replaced mine with a Racor unit.
The Racor unit has a clear bowl on the bottom which holds any water seperated from the fuel.
I was able to temporarily stop sucking air with my Winn unit by using "seal all" on the "O" rings. There is a thumb screw on the top of the unit. Remove that thumb screw and pull the top housing up to release the screen housing.
Chris, Keith Risch at MOT told me not too long ago that the o-rings are the most likely problem area, carry extras with me. He also mentioned a grounding wire. I asked him, what is the most likely problem that I could have on the road that would shut down the coach. He told me that part of the fuel system. So we replaced as you noted. (On an ISM).
Mike
I'm wondering now if there may be something electrical in powering the ECU, or a sensor. I had a problem with that last year. I went back out with the laptop to hook up VMSpc. While that was booting up, I went out and turned off the remote start in the back. Went back up front, turned on the key and it started right up. I think I will replace the solenoid up front, for a start.
Dave:
i know folks who have had eratic engine starting with these failing Winn fuel filters which allow air into the fuel at what appears to be random times. I could never rationalize why the fuel goes down throught the see through screen housing, but did realize that repeated air in the fuel was caused by sporatic leaking of "O" ring seals.
Mike:
With my Winn fuel filter/water seperator/purge pump, new "O" would not have solved the problem because the necks on the see through screen container were narrowed where the "O" rings were. I built carefully sized copper tubes and forced them inside the necks to reshape the neck and that caused a good seal with the original "O" rings. After doing this time consuming job, I discovered that the purge pump was seized, so I replaced the whole unit with a Racor.