Hey guys. You saved me with my T190 issue this spring so I am hoping you can help me out again. I have an older Bobcat 331 mini ex that is getting tired but hey it's paid for and makes my weekend projects easier. It has had an issue lately of stalling out. It will work completely fine for days and then all of a sudden it stalls out under even the slightest load. I had though maybe it had bad fuel or junk in the tank so drained it completely and blew out the lines. Seemed to do the trick for a few weeks but now it is back. Fuel filter is fairly new. Could the fuel pump be going? Does it seem like a fuel issue? Any additives that you guys have used that seem to help clean a fuel system out? I appreciate any help. Thanks
Engine stall is typically a fuel supply issue. When it stalls and dies, is the primer bulb sucked flat? After it stalls, when you remove the fuel filter is it full of fuel? Unless it stalls hard, like the hydraulics puts a extreme load on it and kills the engine quickly, that's a different issue.
I will have to check the bulb and filter. It always starts right back up without any issue. It seems to idle fine but as soon as you do anything with the hydraulics it stalls out. But then like I mentioned it will be fine at times. Yesterday I worked for hours with it knocking down trees and pulling stumps, then all of a sudden it would keep stalling under any load.
I don't have any diagrams for the 331 so I can't help much. This is not easy to describe in words, fuel issue will typically be a slow stall. Engine slows, even labors, spits and sputters at an idle speed and dies. Hydraulic system stalls are different, as in the engine is running smoothly and you work any a function and it dies immediately, much like letting the clutch out too fast on a manual shift transmission.
So what would cause a hydraulic stall?
Sadly, as I stated, I have no information on the 331 to work with to have any ideas, hopefully bobcatdan or crewchief will spot this thread as they have access to more info than I do.
I was running one of my hoes the other day and little to my knowledge the fuel gauge is faulty and it would run from full speed full power to complete silence almost instantly it felt like the hyd pumps stalled the motor completely out ...... After a couple gallons of juice she was good to go, not sure if my story helps you much but made ya read it anyways :tong lol, I would look at a fuel delivery problem as well, swap filters check primer bulb etc. my dad's an old boat mechanic for 35 yrs and you would be surprised how many problems was as simple as a $10 damn primer bulb, check valves would fall apart and plug up.... You would grab it to pump it and it would be hard so you thought it had fuel on the other side at first glance. Pj
Check the pick up line inside the fuel tank for cracks.
That's interesting on the primer bulb. It is pretty hard to pump. I assume that is just a generic part and not bobcat specific? As far as the pickup tube I will have to check that as well.
My service manual doesn't have any information on the pickup line. Is there an easy way to inspect it before I go tearing things apart?
Fill the tank to the top, does it make a difference. That would be your test
It did seem to run fine when the tank was full. I bought a new primer bulb today so will throw that on tomorrow. I can't find anything anywhere about how to pull the pickup tube out of the tank?
Can buy the manual online for $10 at tradebits... btw - from what I see, pain...check to see your overflow tube is clear.
Curious to know if your primer bulb replacement worked for you? As someone mentioned, cracked pickup tube is a possible problem...other stories I've heard are plugged screen (on end of pickup tube), vent tube plugged, fuel line leaks and bad fuel filter. Replacing pickup tube means one has to gut interior. I have AC in mine, so it means removing AC unit whenever mine goes...shame the engineers couldn't have made it a touch easier to get at....
I have not had a chance to swap out the primer bulb yet. It is sitting on my workbench so might try tomorrow. What manual is available there? I have the bobcat service manual but there is nothing in regards to the pickup tube. It looks like it goes through a rubber gasket into the tank. Not sure if I just pull it out or what?
Looks that way.... Also got a parts manual titled _331_331E_334_D-Series_[Parts]_Excavator.pdf It isn't all that great as it is dated and not easy to navigate, but Bobcat has finally put a parts manual online (just go to their site)...have to use IE to view though...
Item #3 in diagram is the pick up tube, and it ain't just plain old nylon tubing.
Thanks for putting that up but my machine must be older as it certainly doesn't look like that. The fuel line on mine goes in under the tank. I just hate to start pulling on things and risking something breaking. I will explore the bobcat site and see if I can find anything. Guess I could also go to the dealer and see what their information says???
Great advice with the bobcat site! Guess its been awhile since I visited that as it was pretty useless for awhile! I found the one for my machine. Looks like the fuel line just connects to the bottom of the tank with no screen or anything?? So now I am very curious to change out the primer bulb. I will let you know what happens. Thanks again.
Not plain? Is propriety nylon tubing with Bobcat printed on the side?
No, it's some other compound, can't remember the chemical name for it. Plain nylon tubing gets hard to the point of breaking very quickly when immersed in fuel. The tubing that Bobcat uses is some other compound, lasts much longer before failing. The stuff Bobcat uses is much more flexible.
I was being a little facetious, but I see the need to buy once with an item that requires me to do a near complete teardown to replace. I have diesel jerry jugs (plastic) that have been around for 10 years...they also get UV abuse.
Note: I'll always be slightly disgruntled about Bobcat's desire to keep their hydraulic fluid secret...it is one of those c'mon man! moments. What it accomplishes is irritation, and because I live far away from a dealer, I don't change the oil as much as I'd like...grumble grumble...
No worries, I only pointed this out (not to sell Bobcat parts) because at first glance one would assume it's ordinary vinyl tubing. Not so, it's something much better in fuel applications, just wish I could remember the damn chemical name for it. :Banghead Well, it's always subject to debate as to what would be equivalent, but I've been using good quality AW46 oils for years in all manner of Bobcat machines with no issues. After all, it's a hydraulic system, pumps, motors, valves, nothing special about Bobcat components that are not common for any other hydraulic system. True, Bobcat may, in fact, have some form of "super tri-calification quad polymer substrate matrix modifying friction modifier" that increases component life, but like I said, it's a hydraulic system, good quality oils have been doing the same thing in the industry for years. JMHO.
OT - Probably time for me to try an off the shelf HF. While the Bobcat HF is only about twenty more than a store brand, getting it shipped adds another 30..... My little window in the reservoir is starting to look like steeped tea....how does one know when it is time to change...I never make the hours.
Well, I don't want to derail nepondguy's thread, but the info is still relevant. Changing hyd fluid? Most schedules of any brand say 1K to 2K hrs. But it's not really possible to completely change the oil in a system, unless you want to take the entire system apart. At best, you can change what's in the reservoir, but there's still a considerable amount of oil in the pumps, motors, oil cooler, valves, and cylinders, and lines. Aside from taking the entire system apart and draining, there's no practical way to completely way to completely change the hyd oil in a Bobcat machine.
Still haven't had time to change the primer bulb but am hoping to sneak out shortly and do it. Just my two cents on the hydraulic fluid...I have not used Bobcat fluid for years in either of my machines with no issues...hydraulically that is!
Have you sorted the stall problem? i have a issue with my Bobcat mini were it stalls sometimes when stretching the boom out and lifting it at the same time, It will re start and run fine, it seems to be some hydraulic issue, and is one of a few funny things that happened, one track running faster than the other etc, after someone tried to steal the hydraulic pump unit, causing the machine to pump out its hydraulic fluid? What causes hydraulic stalls when the machine is obviously not lifting anything heavy??
Sorry for the long delay. I had to do some traveling for work but finally had a chance to swap out the primer bulb today. It is super cold today and after the swap it fired right up! That never happens when it's this cold. I didn't work it too much but so far so good. My fingers are crossed that was it. Thanks for the help guys.
Same problem on 337 d. The tank had some debris in it. My tank is a gravity feed so there was no pick up tube. The tank has two divots in the bottom therefore draining it probably wont help. It is a real job to pull the tank so I removed the seat and then the access plate behind it to get to the fuel level sensor. I then reduced a shop vac hose down to some 5/8 vinyl tubing and began the tedious job of vacuuming the bottom , eventually i came out with a piece of plastic. When the stars aligned just right the plastic piece would cover the fuel drop tube and cut fuel flow, machine would still run but not when you put a load on hydraulics. Hop of when it behaved that way to discover the fuel bulb collapsing. Good luck, and btw I would purchase a new bobcat fuel filter first to rule that out. Our bobcat filters tend to rust at the top if stuff sits for too long.
Just thought I would give a quick update. The machine has been running perfect since replacing the primer bulb. It fired right up in very cold temps the other day and then ran like a champ. Thanks again guys. You saved me a lot of money and aggravation!
Thanks for the update neopondguy.