Traction Tractor stalls going uphill but works fine on flat and downhill

[bearcity]

I recently got a used massey ferguson 1433 HST. Everything appears to work just fine as long as I'm operating on flat ground. At about 10 to 15% grade, the tractor would not go up unless it's on 4 wheel drive and low HST setting. On medium, it will crawl very slowly until the engine stalls. Is this normal for an HST tractor? This is on an asphalt driveway with plenty of traction. All my other vehicles (golf cart, car, truck) going up and down this hill with no problem.

If this is not normal, any suggestion on what to check for problem? Thanks.

 

[George2615]

Welcome to TBN...

Sounds like it's starving for fuel. Have you changed the fuel filter since purchase? Also check the air filter and blow it out or replace it.

 

[nybirdman]

Are you letting up on the HST(up for power,down for speed).Can't depress like a truck,car ect. for more power ,you get less.It should walk up in 2WD if the traction is good.Keep the RPM's up also,I'm guessing 1800-2000 for your tractor.On a used tractor;the wrong HST fluid may have been used/low or the hydo filter plugged.
Also check fuel filter,may be starving for fuel.

 

[k0ua]

I recently got a used massey ferguson 1433 HST. Everything appears to work just fine as long as I'm operating flat ground. At about 10 to 15% grade, the tractor would not go up unless it's on 4 wheel drive and low HST setting. On medium, it will crawl very slowly until the engine stalls. Is this normal for an HST tractor? This is on an asphalt driveway with plenty of traction. All my other vehicles (golf cart, car, truck) going up and down this hill with no problem.

If this is not normal, any suggestion on what to check for problem? Thanks.

No, not normal.. When you say you go up in Medium range the engine stalls.. do you mean the engine actually stops running? What does 4wd have to do with it?... My first thought is the Hydrostat has a problem.. say like a stopped up filter, but 4wd has nothing to do with that. Are you saying it will go up the hill in 4wd Lo range but not 2wd Lo range?.. If that is so, I would ask another person to drive the tractor up the hill and you observe the rear wheels to see if the wheels are turning inside the tires. We have heard of this happening when air pressure is very low in the rear tires, and especially if the rears are filled with RimGuard. My next thought would be that the engine fuel filter is stopped up and when the governor asks for more power the injection pump cannot deliver the fuel rate of flow needed. It is normal to ask more from the engine in HI range than MED, and more in MED than LO range, while the engine should noticabally load down some when trying to climb a hill in HI, it should still do it, not kill the engine, and certainly in MED range. Again some slight RPM drop, depending on how the tractor is loaded or what it is pulling but I have never killed the engine. What I am getting at, is I don't have enough information to be sure of your problem.. You need observe more, and get back with us and hopefully we can help you.

 

[s219]

Are you giving it enough throttle? For reference, I tend to run my tractor at 1800-2200 RPM for getting around. If you have a 2-speed HST, it's possible that low is required for hills. I have a 3-speed, and tend to use medium most of the time, only going into low for heavy work.

Since this is your first post, and we've seen it before, note that the HST pedal is not the throttle (though some manufacturers have an improved HST that can auto-throttle). Pushing harder on the HST pedal is like going into higher gear, and will make things worse on hills. You need to independently give the engine enough throttle and back off the HST pedal when resistance is encountered.

 

[k0ua]

Are you giving it enough throttle? For reference, I tend to run my tractor at 1800-2200 RPM for getting around. If you have a 2-speed HST, it's possible that low is required for hills. I have a 3-speed, and tend to use medium most of the time, only going into low for heavy work.

Since this is your first post, and we've seen it before, note that the HST pedal is not the throttle (though some manufacturers have an improved HST that can auto-throttle). Pushing harder on the HST pedal is like going into higher gear, and will make things worse on hills. You need to independently give the engine enough throttle and back off the HST pedal when resistance is encountered.

Diagnosing problems by "remote control" is fun isn't it? 10 seconds on the tractor would tell any one of us a whole bunch.

 

[Egon]

You gotta check out the fuel system starting inside the fuel tank.

 

[bearcity]

Thanks for the quick responses. I changed the oil, oil filter, fuel filter when I got the tractor. Air filter looks new and clean so I left it alone.

The tractor does seem to have auto throttle. RPM goes up when I step on the pedal harder. Engine was running near red line at about 2500 rpm. Hard to believe it's was starving for fuel.

Yes, the engine shut off completely. I have to step on the brake, put in neutral, restart the engine again then put in low range to continue to crawl slowly.

I tried different combinations. It will go up without stalling the engine in 2WD, Low range. 4WD in Medium range but struggles. Easier with Low range regardless 2WD or 4WD. Stalled a few times even with 4WD in Medium range. I have R4 tires. Dirt or asphalt doesn't seem to make much difference.

On flat ground or moderate slope, everything seems to work fine (1st tractor so I don't have anything else to compare to...). I did some grading, pushed a lot of snow, moved a lot of dirt. The hydraulic seem very strong. It can pickup some very heavy pallet of concrete and other heavy stuff near the limit of the loader's rated capacity.

My neighbor has a similar size chinese made tractor with just a couple more HP but it's gear driven. He has no problem going up and down this driveway at decent speed. On the flat, my tractor seem to be able to do everything the same as his. He actually likes my tractor more than his. I don't know if it has something to do with being HST vs gear??? Also, I'm at about 6500' elevation. Do I need to do any adjustment for this elevation? Thanks again. I appreciate everyone's help.

 

[k0ua]

Well two things I notice right off. The tractor is a little on the under-powered side at 33 gross horsepower for the size/weight of the tractor. I don't know how you have it ballasted, (loaded tires? weights, 3pt weight?.) It is not uncommon for manufactures to make these models that are on the low side of horsepower for their weight, I can think of several examples. Now as for the 6,500 feet, that cannot help. The air is getting thinner up there, and the horsepower is dropping. All that said, it sounds like you are still sucking for horsepower. A hydrostat transmission (That I dearly love) does suck up about 15% of the available horsepower vs. a gear model. It would be very interesting to have a dealer that had a PTO dyno. put your tractor on the dyno and actually measure how much it is putting out. If it is up to spec nothing can be done except put a turbo on it. As for any adjustments for high elevation, I just don't know I have always lived at much lower elevations and have never had to face this. So to summarize, engine HP not all that much to begin with for the size of the tractor, Hydro eats 15%, and elevation steals some amount more, you may be going up the steeper hills full throttle and LO range.. If the tractor still bogs... crank the hand throttle up full, and back off of the hydro pedal to let it catch its breath. Without a doubt adding a turbo would certainly help, but I would like to know if the engine is up to spec first, and this is not some kind of fuel volume delivery issue.

 

[bruceatlam]

I think you need to check your compression. You're most likely not generating the HP that you should generate. The altitude may contribute to that but I suspect a more serious problem. There are basically only four things that I can think of ---- lack of fuel, lack of air, low compression or a hydrostatic transmission problem. I don't see that you've changed the hydraulic fluid/filters??

How many hours on this tractor?? Do you have any noticeable "blow by" when the tractor is running?

I'm afraid that I'm not much help --------------