JD 755 Problem

[zooming993]

I own a JD 755 tractor with about 460 hours on it. I bought the tractor earlier this year so I haven't really used it much, maybe 10hrs. I have a FEL installed and occasionally pull a 48 brush mower. After purchasing the tractor I proceeded to change all the oils (crankcase & Hydraulic) and filters (oil, hydraulic & fuel). Now to the problem I'm experiencing. The tractor starts up with no problem and runs fine on flat land however, when I attempt to climb a hill even a small one the engine bogs down and ultimately dies if I don't lift up on the forward pedal. I first thought I had a hydrostatic transmission problem because when I changed the hydraulic fluid I did not use the JD Hydra Gard fluid, I used Tractor Supply premium brand. Thinking this was the problem I drained the fluid and replaced it with the JD fluid but the problem still exists. Thinking it wasn't the hydraulic fluid causing the problem I started to look into the possibility of a fuel delivery problem. With this in mind I took the tractor for a spin around the property and while doing so the oil light flickered on and off briefly so I turned off the engine. When I got off the tractor I noticed a few drops of oil dripping from the bottom of the tractor so I pulled it into the garage to investigate further. It turns out the oil came from the overflow tube coming from the valve cover. When I went to check the oil level I was surprised to find the oil level well above the full mark, my first thought was I blew a head gasket but there was no evidence of water and the radiator was still full. Now I'm really scratching my head trying to figure out what was going on. I know I didn't put to much oil in when I changed the oil because I still have some left in the 1 gallon container. Then someone told me it could be diesel fuel so I'm now trying figure out if it is? I'm leaning towards it being fuel because I know it's not water, could it be hydraulic fluid? I tried to see if I could smell diesel fuel on the dip stick but I couldn't tell.

Thanks for your help

 

[yankeerider]

Let's take one thing at a time. When the tractor wants to die on a hill, are you running in hi range or low range? If hi range, with a loader on, you should expect to have to back off on the pedal, which has the effect of gearing down.

Since nothing seems amiss with any of the fluids, just get their levels right, keep an eye on them, and report back.

 

[zooming993]

Thanks for the reply. I did have it in low gear when trying to climb the hill. When it starts slowing down I do lift off the forward pedal and it's at this time the tractor slows to a snails pace.

 

[gsdavis1]

Sounds like maybe a restriction somewhere....could it be a clogged filter??

 

[Dennisfly]

For the loss of power, I'd be suspect of fuel delivery. Is the pickup screen in the tank unobstructed and the fuel lines not kinked or plugged? Oil out of the breather would be indicative of excess blowby and the oil light blinking doesn't sound good. Low power, low oil pressure, and excessive blowby all sound like a high time, worn engine. Are you sure the tach didn't break and someone replaced it? That is very low hours for a tractor of that vintage. I have an 855 that I bought with 132 hours on the tach but the tractor was 20 years old and it was obvious the tach was newer. This wouldn't explain the increase in the oil level though.

I don't know much about the injector pump, but I wonder if it's possible that there is an internal leak that puts fuel in your crankcase and provides less than adequate fuel to the injectors. The diluted oil could explain the low oil pressure too. You might want to consult a fuel injection overhaul facility and see what they think. I know you want to leave any high pressure fuel pump work to a skilled shop.

Good luck.

 

[zooming993]

Dennisfly,

Thanks for the reply. I recently cleaned out the tank and to my surprise there was no strainer attached to the sender. There was some sludge at the bottom so I cleaned it out and put a new strainer on and I'll hope for the best. The fuel line isn't plugged or kinked. As for the hours shown on the tack, I can only hope there correct. The guy I bought it from said they were actual hours but I guess you never know. I ordered a new fuel pump I should receive it next week. The pump on it now works but it doesn't sound good, it sounds like it cuts in and out. As for the injection pump, it may be leaking internally but I haven't figured how it would leak into the crankcase.