I was out plowing snow to open up the work road and all of a sudden with no warnings my dozer died. I have oil, coolant, good batteries and the engine turns over. I checked the air filter, it was a tad dirty but not at all blocked. I changed out the fuel filters and bled the fuel system. I noticed on the primer pump that the little pump handle doesn't lock down like it says it should be in the manual, but I was still able to move fuel through the system. Could that be part of the problem? Also when I took the old filters off and drained them of fuel, the fuel was a purplish color (like watered down grape juice) and black specks in the fuel. I do run dyed diesel but that is more of a pink color. I have filters on my fuel holding tank and truck tidy tank. I also change my fuel filters on the dozer every 500 hours as specified by the manual. The machine was blowing some grey/black smoke before it happened, but has been doing that for sometime now. Also when turning the engine over now, there is no smoke coming out the exhaust at all. I know this is a very vague question but what could possibly be wrong why it just stopped dead. The dozer is an old 1984 JD 850b. I am hoping and praying that my machine didn't decide to keel over and die. Please and thank you for your time.
I don' tknow the JD in particular, but check to see if there is a primary filter screen. You may find it is finally full of crud. If so, clean it out, and replace the spin on filter. When you take the primary off, wherever it may be found, check that you have good fuel flow from the tank. If so, prime it up and try again. If not that, you may have a fuel pump problem.
Could be a fuel supply issue caused by plugged or restricted supply line to lift pump or a bad lift pump,did the machine fire back up after you bled the system? Also check for any water/sediment if there is a sediment/water drain at the bottom of the fuel tank.
could be a blown fuse or broken wire to the injection pump.
I am not sure but do these have a banjo bolt with gauze in the middle like in Hitachi Excavators? If so it might pay to check that too. I had an EX300 do that to me at work a while back when the gauze bit in the Banjo bolt in the fuel line filled up with dirt and such. Hope you get it fixed
Check for a shut off solenoid on the fuel pump return-to-tank side. If return flow downstream of the injectors is obstructed, the main pump shuts down. This, assuming you have that setup. I'm only familiar with the 450C model. Someone else had this problem a couple of weeks ago. Can't remember what the resolution was.
conky, does this machine have a in-line injection pump with a manual shut-off cable?
I have a 1981 750 E that did the same thing. It was the seloniod on the injector pump. dad was going along and thought the volt meter was reading high and shut the master battery switch and the mashine stoped dead. Would not start and found out it fryed the selonoid. If thats the case JD sells the seloniod for about 250 bucks.
Problem resolved (for now) - It was a loose ground connection on what I assume was the automatic fuel shutoff solenoid or injector pump. Thanks as always for the help.