Have not started coach in about a month. Needed to prime fuel to start. Is this normal? Replaced all fuel lines last February. No fuel leaks on blacktop. Needed to prime last time started too. What's up with this? Where is fuel going and why losing prime?
You don't have to have a fuel leak to have to prime engine. Sucking air in one of your lines for sure! I'm sure others will chime in here for help!
At least you can disregard condition of the fuel lines from the tank back but I would re check tightness on the fittings. Then I would put a wrench on every connection where fuel passes thru ie injector lines and so forth. This won't cost you anything because you can do it. This is starting with the easiest and see if any improvement before moving to replacing parts. Mine lost prime a couple months back and it was the lift pump but I did all the above before moving on to possible parts failure. Mine is a mechanical 8.3 but everything has to be tight for any diesel to hold prime. Hope it's that simple and many times it is.
Could it be o- rings on pre filter? I'm going to replace all. Do they go bad frequently?I have read numerous times on forum that the system is not well regarded. I have almost 100 of each size.
No harm in changing.
Looking for such as this is where a 150.00 per hour shop can tear a wallet up. The things I listed and may have missed you can do and avoid that.
If you have compressed air you could go to the fuel tank and make a seal with a shop rag and put a bit of pressure in the tank and have help stand at the engine and look with a flash light. Not a lot of pressure and if the tank is full be careful when you take lift the rag or it will wet you with fuel.like Joe said you can still be getting air in without leaking fuel out so all the tightening I mentioned still applies.
I had a primary filter with the water drain leaking air in at the drain. Pain to find
If your pre-filter fuel level is 1/4 or less after sitting then you should remove the pre-filter and put in new O-rings (4). Clean the pre-filter while it is out and reinstall. If the plastic ends are distorted it will leak fuel or air. I carry a new spare pre-filter just because. And 2 each of the other fuel filters.
Run the air purge a couple of times, start the engine and run on the first high idle for three minutes. (Cruise control on and press the set button.)
Clean everything up around the top and bottom of the pre-filter and fittings. It may be dirt dirty but it shouldn't be fuel dirty. It is always easier to check for leaks when is clean to start with.
Thanks. Have a spare and plenty of o-rings. Will clean up the one I take off and keep as spare. It is only year old. I have algae in tank and am planning on trip to FT in spring and plan on getting fuel scrubbed. I'll start checking fittings tomorrow. Leaving for short trip to Orlando next week wasn't planning on this. Lots to do
Is it typical for a M11 to have a pre filter water separator with 4 O rings in it?
Yes on the factory Winn Racor 300200
If you have algae in the tank, your filters will take care of it plus, use the HWH to lean the coach over and with a LED, check to see what is on the bottom of the tank. Use suction to remove any algae, water, etc.
Polishing fuel is a huge waste of money as a clean tank is only clean until the next fillup where you have no idea what's in their tank.
Use an additive to kill the algae so it does not get worse.
Pierce
Might have found fuel line leak. Severely misshapen inlet/ outlet ports on Winn pre filter.
Racor 300200
U320 fuel screen (https://www.foreforums.com/index.php?topic=40443.msg402725#msg402725)
[300200]Racor 300200 Prefilter W/ O-Ring - 200 Mic (https://www.dieselfiltersonline.com/300200-racor-300200-prefilter-w-o-ring-200-mic.html?gclid=CjwKCAiAh_GNBhAHEiwAjOh3ZHdgXKIXAW8G5qQ17wKn687j_2M50IKHHV6pTtyenoKlbzUOuPOxnBoCEyIQAvD_BwE)
Realized I never posted o-ring part numbers.
Scott
Takes two each of the o-rings on each end
Item ID: O-ring AS568-114
AS568-114 - O-ring
AS568-114 - O-ring (https://www.allworldmachinery.com/itemdetail/AS568-114)
Standard Dash Size AS568 -114 B70 (NBR) Buna O-rings 50 Count Orings Bulk | eBay
----------------------------------------------------
Item ID: O-ring AS568-208
AS568-208 - O-ring
EAI AS568 O'RING Seal #208 (20PCS) ID 5/8" CS 1/8" NBR Oring 5/8"x7/8"x1...[/url
AS568-208 - O-ring (https://www.allworldmachinery.com/itemdetail/AS568-208)
The plastic pre filters can crack the bowel very easily and the crack is hard to see. Runs poorly that way .
On a related topic I've attached a photo of my Winn pre-filter while the engine is idling. Does this look normal to those of you who are familiar with this filter set up? The fuel stream is flowing in at virtually the same rate that it is flowing out and there is usually little or no fuel accumulated in the reservoir. When the engine is off the fuel level is usually about half. I have no engine problems at all and it runs strong without acting like it's starving for fuel. It just seems like that filter should be full. Any guidance on this is appreciated.
I have had 2 coaches with the Winn filter and both worked like yours.
I think Racor makes a water/ contaminate filter similar to that and when it is full indicates it needs changed as in contaminated.
The distorted end will cause both air leaks and fuel leaks. When you reassemble it lube the rings with a bit of silicone plumbers grease or some fuel. Be careful with alignment during reassembly.
George, yours looks about right. When you shut the engine off it will be 1/2 to 2/3 full. I don't see any fuel/dirt at the top or bottom and the screen looks clean. If you get black flakey stuff in there it is algae.
As I have mentioned in other threads, the original Winn filter system on our 1995 U320 became problematic--particularly in colder weather. Despite my best efforts at maintaining it, I still had problems (due to fuel starvation) starting the engine in cold weather.
A few years ago I replaced the Winn system with the Parker 790R30 system and haven't had those issues again. I highly recommend it!
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.
George there is a Schroeder valve on mine at about the top left of your photo just out of view. I bleed the excess air out with the purge pump. Mine runs at about half full of fuel. Was low when I had air leaks in the system. David I originally thought I would go to the filter Racor 700 series but have since decided I want the benefits of the FASS pump system because of the lift pump and positive air removal. I do know for a fact our main fuel pump runs and draws a vacuum while operating. My fuel minder indicator I added always shows half scale-goes higher if filter is plugged. Vacuum actuated. The 700 only has a purge pump.
Scott
Lift Pump for 01 U320 (https://www.foreforums.com/index.php?topic=41496.msg413591#msg413591)
I planning to put a Fass system in my coach soon. One of my concerns is the return
line as I have phoned Fass and they say it needs its own entrance back into the
tank. If I had of know about the Fass system when I did my fuel lines I would have
welded a bung into the tank. They have a system where I could cut the fuel fill
neck and put it in there but I'm not sure I want to do that.
Yes I agree about adding another bung. So in pondering about this for a month I think one could add the return in one of the other return fittings. Generator returns very little fuel. Generator line on my coach is 3/16 line and steps up to 3/8 return line at tank. Should be sufficient for return of air and generator return demands.
Scott
Scott I think they want a 1/2 fitting for the return line. I will call them again. I could
weld a bung on that angled piece off the top of the tank so I will check with Fass
to find out if the return could be in the diesel when the tank is full. I would also like
to pull the return line without dropping line cover in the main storage area.
My turn with the 300200 it appears. I changed the spin on filter next to this and purposely didn't touch this guy, and now it's leaking. Ordered a new one online. I read somewhere about removing the thumb screw to remove this...does someone have the link?
If you reused the old fittings, that may be the issue...I reused mine and it was a stupid mistake. If you score (even in the slightest) the old fittings and reuse them they WILL allow air in the lines. I had to replace them after so I got new fittings and added clamps to boot. Sorry you are having an issue and I know it is the last thing you want to do over but I have had no issues since I did the fix. Good luck.
I didn't touch the 300200 plastic see-thru assembly, but it is leaking now, so I've ordered a replacement. Just need to figure out how to remove and replace it properly.
Keith,
You may just need to replace the O rings in the filter you have.
Mike
As I have written before I believe if you replace that old system with a Parker/Racor 790R30 your problems will be solved. That's what I did and it solved mine.
Thanks Mike...didn't want to take the chance of taking it apart and having an issue, so a new one is on the way. I've not had issues until I replaced the spin on filter next to it last night.
DJ, I've seen your info as well but I'm hoping this $65 fix works. I've not had an issue with this previously and would rather not spend another $400 on the coach right now.
I understand your reluctance to spend additional money on this but (for me at least) it was worth it to resolve a recurring problem and to avoid (once again) being stranded in a remote location. Good luck!
Take the wingnut off the top and lift the housing up to get to the filter. It is cleanable but if cracked has to be replaced.
There are O rings on both ends of the plastic filter, easy to replace.
There are 2 o rings for each end of the plastic filter. One on each end is visible but the other ones are inside the housing.