Hi, new to site. Thanx in advance for any help. Here is the sitch. One day my Bobcat is running fine. The next day suddenly the throddle is responding funny. Was doing some aggresive side to side grading work when problem started. It idles down and shudders as if it is going to die. Also, when I push the throddle forward, it takes several seconds to actually throddle up. First thing I tried was replacing the fuel filter and bleeding out air. No change. Second, I topped off tank, (although it was half full when problem started). These things did not fix problem. I'm thinking it is hose or filter going into fuel tank based on my forum research so far. What do you think, and if I am right, how the hell do I access this area for repare? Please don't say remove tank and/or hydraulic pump!
Wade - My Cummins [in a Trojan] started something similar a few weeks ago, and i'm pretty sure it's water in the fuel thats freezing. I've drained some in a few places, and see blobs of water in the bottom of whatever pan I use. It's better now, I just need to get a new filter & water seperator canister. It ran pretty much as you described, then would take off and be fine for 5 or 10 minutes.
Welcome to HEF Wade W. There's a strainer screen on the end of the pick up tube inside the tank. If this screen gets clogged by debris it will cause these problems. The best way to verify the strainer screen is clogged is when the engine stalls out you immediately check the primer bulb to see if it's sucked flat. If it is, strainer is clogged. BTW, you can't blow back through the fuel line with compressed air to clean strainer screen. It has a check ball in it, you'll simply blow the fuel pick up tube off with compressed air. Here's a pic of the 853C fuel tank viewing from rear of machine with engine removed. The fuel sending unit is noted with a 1. To the left of that is the fuel pick up, farther to the left is the return, don't mess with that one. Of course these components are underneath the hydrostat drive pump. A PITA to service, but can be done (with many curse words) without removing engine.
Good Morning, I have an 853 Bobcat with a fuel problem as well. I worked with the Bobcat dealer in Toledo Ohio after I made several errors in my troubleshooting efforts. When the problem first occurred the engine would loose power and start to slow. I limped back to the barn and changed the fuel filter (to no avail) found an obstruction in the fuel line , used compressed air to "clear the line". Big mistake, blew the hose off the tank elbow , inside the tank. None of these things were apparent. You can not do any thing to the top of the fuel tank with the engine still in the machine. The engine must come out. A special bracket must be fabricated to pull the engine. This is a miserable job. Also remember as you are pulling the engine (and the Hydraulic pump) unplug the fuel sender cable. Lots to this job good luck.....
I beg to differ, it is definitely possible to remove the pickup tube with the engine in the machine. They way we do it, (my old company owned 3 853s, all POS) is obviously lift the cab, then get a 2x4 to lay across your midsection, because it will be very painful as it is a Bobcat and nothing can be easy. The elbow is held in the tank by a rubber grommet and pops right. Much patience is needed but one will get it.
Hey CaptainAnalyzer - You wouldn't want to detail that procedure would you? I have a 553h and need to replace the fuel sender, and would prefer no tot remove the engine to do it.
You have to remove the engine to do a sending unit. I'm talking about the fuel pickup tube.
I had the same problem with a clogged fuel screen on my 1991 853. Thanks for the advice from this thread. I changed out the filter and line today. If you are planning on doing this job there are a few things I learned that can help you. First, wipe the top of the fuel tank well before you start. To access it, raise and lock the lift arms and raise and lock the cab. You can see the fuel grommets under the hydrostatic pump. I could reach the grommets from either side and in different ways. Next I disconnected the fuel line at the primer bulb and I used a couple of hose clamps to attach a new 6 foot fuel line to the old one. This way I can pull the new line under the engine when I get the screen out. To get the grommet out, I used a two prong puller I bought a number of years ago for taking apart steering linkages. They sell them at just about any auto parts store and I found it was an invaluable tool for this job. I pulled the new line through and disconnected the old elbow and grommet. My pickup tube was completely disintegrated and the old screen has been entombed in the fuel tank. I cut off the old fuel line and grommet, and installed the new kit (14 bucks from bobcat). Putting the grommet back in turned out to be the toughest part for me. After about 90 minutes of wrestling with it, I finally got it to seat through a combination of dish soap on the grommet and two of the aforementioned pry bars pushing down on the rubber part of the grommet. From there I installed a new primer bulb and short lines, primed the line and she started right up. I spent the afternoon working on digging my future basement and she ran great. Thanks again for the advice and I hope this helps future bobcat owners. Total time: 3.5 hours total cost: $35.00 Much better than pulling the engine out.