B7800 Losing Power

[snmhanson]

I have a B7800 that I bought new about six years ago. Moderate home use over the years and though I have pushed it at times, I have generally kept up on maintenance. Last year I noticed when I used the mower deck it will struggle and bog down when going even slightly uphill or cutting longer length grass. It generally happened only until the tractor warmed up and then it seemed to run fine.

Today I was using my landscape rake to grade our gravel drive. I had the same thing happen where the power just seemed to fade. If I took my foot off the throttle a bit the power would run back up. Basically, it just seemed like I was working the engine too hard, but I have used the tractor for this before and it handled it just fine. In other words, my tractor just doesn't seem to be able to handle the load that it used to. The engine temp reading never got above the "C" on the gauge, but the tractor did seem to get a bit warm under the seat area and I think I was able to make out a slight smell of burning rubber. The tractor also seemed to not want to roll very easily unless I was pressing the throttle with my foot. I am wondering if the brakes are stuck or something causing the engine to work overtime. I have in the past accidently driven the tractor a bit with the brake locked.

I am hoping someone can point me in the right direction, whether this relates to the brakes or something else. It is likely I will have to bring it into the shop, but I would at least like to get an idea of what I am looking at before bringing it in. And it is always possible I could fix it myself. Any idea?

Thanks,

Matt

 

[kuboman]

I have a B7800 that I bought new about six years ago. Moderate home use over the years and though I have pushed it at times, I have generally kept up on maintenance. Last year I noticed when I used the mower deck it will struggle and bog down when going even slightly uphill or cutting longer length grass. It generally happened only until the tractor warmed up and then it seemed to run fine.

Today I was using my landscape rake to grade our gravel drive. I had the same thing happen where the power just seemed to fade. If I took my foot off the throttle a bit the power would run back up. Basically, it just seemed like I was working the engine too hard, but I have used the tractor for this before and it handled it just fine. In other words, my tractor just doesn't seem to be able to handle the load that it used to. The engine temp reading never got above the "C" on the gauge, but the tractor did seem to get a bit warm under the seat area and I think I was able to make out a slight smell of burning rubber. The tractor also seemed to not want to roll very easily unless I was pressing the throttle with my foot. I am wondering if the brakes are stuck or something causing the engine to work overtime. I have in the past accidently driven the tractor a bit with the brake locked.

I am hoping someone can point me in the right direction, whether this relates to the brakes or something else. It is likely I will have to bring it into the shop, but I would at least like to get an idea of what I am looking at before bringing it in. And it is always possible I could fix it myself. Any idea?

Thanks,

Matt

Are the brakes off

Change the fuel filter. Sounds like a plugged filter.:thumbsup:

 

[snmhanson]

The brake lock lever is up so the brakes should be off. I'll start with the fuel filter.

Thanks!

Matt

 

[JerryG]

How long has it been since the hydraulic fluid and filter been changed? Was there any fiber in the fluid, filter or screen?

 

[whistlepig]

Lose of power means lose of fuel or air on a diesel. If you suspect the brakes put it in neutral and see if the tractor rolls easily when pushed on level ground. Check the fuel cap to see if it is venting. Replace the fuel filter if needed. Check the air filter. Check the fuel system for air leaks. If it is bleeding air it will be leaking fuel from the same place when the motor is not running. Give the motor a good washing and drying and then check for fuel leaks. It may not be one big leak but several small leaks of air that causes it to lose power.

 

[Verticaltrx]

My first guess would be air filter, second would be fuel filter. The air filters on these tractors are pretty small and it doesn't take them long to get plugged in dusty loader or mower work. If that is good check the fuel filter.

 

[easygo]

Last year I noticed when I used the mower deck it will struggle and bog down when going even slightly uphill or cutting longer length grass. It generally happened only until the tractor warmed up and then it seemed to run fine.

Basically, it just seemed like I was working the engine too hard, but I have used the tractor for this before and it handled it just fine. In other words, my tractor just doesn't seem to be able to handle the load that it used to.

Matt

I'm glad you posted this as I noticed something similar with my B7800 too a few days ago. I only use it in Hi gear two or three times a year and it just would not have the power it had when I used it in Hi last time. If the above posts are correct it will have to be the fuel filter. I put a fresh air filter in my tractor last fall and it has not seen any dust during the winter for sure. So. I will start with the fuel filter and see what happens. Please post something about it in case you are able to change the filter before I do. I will do the same but it will be a few days to a week before I get to it.

here is a thread about purging the air from the fuel line
www.tractorbynet.com/forums/kubota-owning-operating/127778-bleeding-fuel-line-3030-a.html

 

[CompShooter]

I had the same problem this winter. Turns out a mouse built a nest near my air filter. Threw him and his nest out then power was restored.

 

[snmhanson]

I ran to the shop and bought a new air and fuel filter. Replaced my air filter and the old was was pretty dirty. Couldn't see light when looking inside it on a sunny day. Haven't gotten around to the fuel filter and I haven't put any load on the tractor to determine if it was a dirty air filter.

However, I pulled the tractor into the garage where the ground is flat and smooth. I tried to push it while it was in neutral as whistlepig suggested and it wouldn't move. It rocked back and forth like a car that is stuck in gear but the wheels wouldn't turn. I am still wondering if the brakes aren't stuck somehow. Are the brakes something I could check out and possibly work on myself or should I haul it to the shop? Like I said, I did drive it a few times in the past with the brake lever engaged so I wouldn't doubt that there is an issue with the brakes. Or could this be something as simple as time to change the HST fluid?

Thanks,

Matt

 

[kuboman]

I ran to the shop and bought a new air and fuel filter. Replaced my air filter and the old was was pretty dirty. Couldn't see light when looking inside it on a sunny day. Haven't gotten around to the fuel filter and I haven't put any load on the tractor to determine if it was a dirty air filter.

However, I pulled the tractor into the garage where the ground is flat and smooth. I tried to push it while it was in neutral as whistlepig suggested and it wouldn't move. It rocked back and forth like a car that is stuck in gear but the wheels wouldn't turn. I am still wondering if the brakes aren't stuck somehow. Are the brakes something I could check out and possibly work on myself or should I haul it to the shop? Like I said, I did drive it a few times in the past with the brake lever engaged so I wouldn't doubt that there is an issue with the brakes. Or could this be something as simple as time to change the HST fluid?

Thanks,

Matt

Was your range lever in neutral? It will act like it is stuck in gear when you try and move it if the range lever is still in high or low. It is trying to pump oil backwards so there is quite a bit of resistance. If everything is in neutral and you cannot move it then you may have a brake problem.