I recently discovered my old ASV MD2810 fuel tank innards are all scummy & rusty when the machine quickly plugged a couple of disposable pre-filters. I drained that tank and while trying to decide how it's best to deal with it I've cobbled up a temp tank, using transparent urethane hoses. Because the hoses are transparent, I can see that there's a LOT of air in the lines, starting where the fuel exits the filter, and perhaps more by the time it's been run through the IP and is traveling through the return-hose to the temp tank - where it looks more like suds than fuel because of all the air. This ain't normal, is it? I could put this down to, oh, I don't know, vacuum-boiling of entrained air in the fuel from being sucked through the IP, but the idle varies a lot (new problem) and keeps making me think it's about to stall - and it doesn't start as easily as before, either. I know next to nothing about rotary IPs but since there's no lift-pump, I gather they produce enough suction to draw the fuel up from the tank and through the filter. If there were a leak up high in the filter-housing, I'm thinking that might do it (and no fuel would drip out after shutdown). I've spun the filter off enough to look at the o-ring gasket and seat, and they look OK. There's a crappy purge-pump built into the top of the housing (no handle on it) so I suppose there might be a leaking seal in that. Anyone been through something like this? --Dave
Get some good screw type hose clamps on every connection and see what it does.
I'm sure that's it. No problems like this before you put the temporary tank on? What is that, a pump sprayer? That urethane hoses looks to be ridged, with no clamps it's sure to suck in air. Also you can put two clamps on each end, screws opposite each other(180 apart).
Clamp the lines 1st and if problem still present, ditch the filter housing and filter.. ACTUALLY, you could just by-pass the filter hsg right now... just CLAMP the lines 1st.. go straight from the tank w/ the clear lines and back.. Another thing too.. is there another feed off the return from the injectors.?? Might just have a leaking return washer on the injector..
Maybe y'all haven't had the pleasure of working with fuel-compatible urethane hose like this stuff, but I'd bet a thousand bucks it's not leaking at any of those joints. The stuff is very compliant, rubbery, and absolutely seals on even the slightest of barbs - in fact, you can see that it seals by the appearance of the material at the 'bulge' where it goes over a barb. Adding hose-clamps tends to damage the tubing & in my experience is more likely to CAUSE leaks than to stop any of them. When I need to get the stuff off of a barb, it's not easy - it's 'sticky' and needs to be worked off from the end of the tubing; you can't pull it straight off. Later this AM when it's not so quiet out I'm going to soap-spray the filter-head/primer pump area, to see if that changes anything.
I'll take your word on the hose. The filter housing leaking and the filter being plugged from the gunk are the obvious suspects to me. What are you thinking the soap spray is going to do? Are you going to use air pressure on the tubing? Could run it a minute with the tank above the engine, then shut down, check it for the next couple of days to see if that little bit of pressure caused any wet spots. Or I was thinking using an oil can to go over the potential leaks on the filter housing, starting with the pump on top, and watching the return for less air.
Cut the lines off the fuel filter, connect them together with a diesel rated inline fuel filter temporarily to keep the elephants out, air should go away. I think your primer pump is the culprit. :my2c
OK, so your 1,000 dollar hose is not the problem. The primer pump was there before and worked fine. I suppose the seal could be bad now if you used it and haven't used it before. After you solve the problem and it turns out to be the primer pump, can you put a new seal in it or take it out and plug the hole? Maybe the real problem is it's a skid steer and not a backhoe
I freely admit I could be totally wrong, but aside from a tractor that has a high fuel tank that gravity feeds the injection pump, I've never seen a diesel injection set up like in your pic that doesn't use a lift pump, and there ain't no lift pump in that pic. That's not to say your machine/engine requires a lift pump, I'm only saying I've never seen that before. :beatsme And what's that pin looking thing at the top of the filter housing, is that's what's left of a (now broken) primer pump that's been mentioned by others? If so, that sure looks suspect.
solution This was one of those fix-its where, as I was writing about the problem, I realized I probably had come to realize where the solution lay (but it was night by then, so I couldn't check) - and writing about it (or telling my wife, who doesn't really want to hear it) does the trick. Delmer, my soapy water would have been a bad idea in this case (meant for a quick vac-test-seal of the imagined small air-leaks around the primer-pump moving parts) but I didn't want to have to slop oil all over for the same purpose, either, so I simply swiped some grease into the suspect areas with my index finger, and...presto, no air coming out of the filter, and after a few minutes, almost none coming out of the IP return-hose either. Having these transparent urethane hoses in a system speeds fuel-system problem diagnosis immeasurably in my experience. I plan to replace the filter-head before long with a double "CAV style" filter setup that's apparently common on certain Ford tractors, so that I will have a glass bowl (more visibility...) in the mix as well as better filtration, in theory...but that's another post. Thanks for the input, all. --Dave
Willie, Thanks for making me not feel as green as I might otherwise have. No lift pump, confirmed by the mfr a few months ago when I called to ask about that. And the tank is actually well below the filter head, too, so it's even less 'normal,' I suppose. Indeed, that pin-looking thing is a machine-screw that I worked into the existing threaded hole, formerly naked & how I bought it... I didn't know that it even was a primer-pump until I checked with the factory techs, because it's about as incognito as it could get and still be one. I think the fat & stiff maybe-replacement hydraulic-hose that passes basically right on top of it must have made it "necessary" for someone to do away with the old pump-handle. And I guess it was my bad for trying to make that primer actually WORK a few months back, since that's almost for sure when the air started getting into it - right on, Blueboy. No disassembly/repair possible from what I can see of it, either - can't imagine access from the inside only, and the top is crimped over for good. Look for my upcoming thread on my bafflement about intended replacement double-filter head unit... Mahalo - Dave