Kubota 5030 HST problem

[millstreaminn]

My brother brought me his 2005 Kubota 5030 HST to look at. This tractor/loader has 1250 hours on it and has not been taken care of. He makes silt sock for the gas companies and uses this tractor to load mulch into his sock maker. Dusty, dirty conditions.

Here's the problem. If you set the engine to 2000 rpm and take the tractor into a pile of mulch, the rpm's drop to 1200 and the tractor almost stalls. If you let off the hydro pedal, the rpm's come back up. The loader works fine, up, down pressure will lift the front of the tractor up with no engine lug. The only time the engine lugs is when the HST tranny is engaged more than 1/2 way.

So far I changed the fuel filter (very dirty) drained the fuel tank and changed the hydraulic filter (looked like new). I checked all the fluids in the tractor and they look fine and were at proper levels. I called my Kubota dealer and they said to change the hydraulic fluid. 15 gallons of Kubota fluid is $325.00. Kubota recommends changing this fluid every 400 hours and this tractor has 1,000 hours on the fluid. I'm not opposed to spending the money for the fluid, but I just can't see it causing the stall problems?

I am going to hook the tractor to my irrigation pump tonight so I can load the engine with the PTO. I really can't tell if the engine is lugging because of something wrong in the hydro or the hydro is fine and there is a problem in the engine.

So my question is this: Has anyone every fixed a hydro problem by changing the fluid?

 

[Balin' Wire]

Yes. Hyd fluid breakdown can cause problems but I doubt it after only 1250 hrs. I would suggest taking an oil sample and getting it analysed at a lab. If there is an SPL lab or heavy truck shop close, they can get it done for about $20. The sample will tell you a lot more than the condition of the oil. It will tell you what the particle load is and that will tell you if something in the hydraulic system is wearing out. Take the sample after the fluid is warm and while you're at it, look at the color and feel the texture. That can give you an initial indication. Don't mix fluids. The additives from one can react with the other and make a mess of the internals. Be careful of HOT fluid as it can burn you!
Agree to work the PTO w/o the loader to see if it's something else.

 

[D2Cat]

I'd suggest you go here and post your question. Good board, get quick answers, and knowledgeable participants.

http://www.orangetractortalks.com/forums/

 

[millstreaminn]

Thanks. I posted over there.

 

[bigbull338]

ok now im going to have to bend my brain as ive ran hsts.yes you need to change the hydro fluid as well as the hydro filters.if my memory is right theres 3 hydro filters to change.your looking at over $500 todo all of that.if the hydro oil is dirty you may have to change everything again.

 

[millstreaminn]

BB- I went to the dealer and got the "complete" filter and fluid kit. Was very close to $500.00. There was only 1 hydro filter in the bag, though.

 

[hurleyjd]

My brother brought me his 2005 Kubota 5030 HST to look at. This tractor/loader has 1250 hours on it and has not been taken care of. He makes silt sock for the gas companies and uses this tractor to load mulch into his sock maker. Dusty, dirty conditions.

Here's the problem. If you set the engine to 2000 rpm and take the tractor into a pile of mulch, the rpm's drop to 1200 and the tractor almost stalls. If you let off the hydro pedal, the rpm's come back up. The loader works fine, up, down pressure will lift the front of the tractor up with no engine lug. The only time the engine lugs is when the HST tranny is engaged more than 1/2 way.

So far I changed the fuel filter (very dirty) drained the fuel tank and changed the hydraulic filter (looked like new). I checked all the fluids in the tractor and they look fine and were at proper levels. I called my Kubota dealer and they said to change the hydraulic fluid. 15 gallons of Kubota fluid is $325.00. Kubota recommends changing this fluid every 400 hours and this tractor has 1,000 hours on the fluid. I'm not opposed to spending the money for the fluid, but I just can't see it causing the stall problems?


I am going to hook the tractor to my irrigation pump tonight so I can load the engine with the PTO. I really can't tell if the engine is lugging because of something wrong in the hydro or the hydro is fine and there is a problem in the engine.

So my question is this: Has anyone every fixed a hydro problem by changing the fluid?

Does the tractor have hi low shift somewhere and you have it the high range. Yes I know this is a stupid question to ask but I asked it any way.

 

[fitz]

Thanks. I posted over there.

I'd also try ssbtractor.com and go to the Kubota tractor discussion boards. Post question and ask for a response from jm.
That guy is a real Guru.

 

[bigbull338]

the $500 is right to buy all of that.my hst was a 2010 mx5100 hst.it had 2 hydro filters.so your 5030 may only have 1 filter.

 

[millstreaminn]

BB- You were right. There are 2 filters on the tractor, one on each side of the tranny. I figured that out when I had one left in the bag from the "complete filter kit" I bought from the dealer.

Here's some more info from what I did to the tractor last night. I am posting on another kubota forum, so I copied and pasted it:

Hi.

Thanks for the replies.

I took the loader off and have been driving the tractor up and down the road. I set the rpm's to 2,000, tranny is in high gear and I take off. With the pedal half way depressed, the tractor moves fine and the rpm's stay just under 2000. When you quickly and fully depress the hydro pedal, the rpm's drop to below 1,000 and the tractor will stall if you keep the pedal fully pressed. This is on level ground too.

I hooked the tractor up to my irrigation pump (the pump only requires 30 hp to run) and the engine didn't seem to hesitate when the pto was engaged and the throttle was run at speed.

So far I have changed EVERY filter on the tractor. The only thing I haven't done is change the hydro fluid. I have 15 gallons of it sitting in the shop but am hesitant to change it until I have a better idea of what the problem is.

Thanks-Scott

 

[bigbull338]

i knew there was 2 hydro filters on my hst tractor.so i knew yours had tobe the same.now for the bad news.since you didnt change the fuild when you did the filters.youll have to buy new hydro filters when you change the hydro oil.

 

[Kingfisher]

i knew there was 2 hydro filters on my hst tractor.so i knew yours had tobe the same.now for the bad news.since you didnt change the fuild when you did the filters.youll have to buy new hydro filters when you change the hydro oil.

Why? If his sample shows nothing coming apart internally and the fluid is just " worn out" why replace the filters?

 

[millstreaminn]

Hello. Thanks for the replies.

I my neighbor saw me fiddlin' with the tractor in my shop last night so he stopped over. As luck would have it his nephew is a Kubota technician.

His nephew was at my shop within 1/2 hour. As soon as he started it up he said a cylinder is not firing. I asked him if he wanted to drive it. He said nope, it's not a tranny problem, it's an engine problem. He took the injectors out and took them to work to test today. He thinks an injector is bad. I hope...

 

[bigbull338]

to answer your q if the hydro oil gets dirty it will affect how the hst works.so you have to drain the oil and change the filters again.even on my 7040 hydro shuttle the hydro oil has tobe changed every 400hrs along with the filters.

 

[millstreaminn]

Well the Kubota tech stopped up and looked at the tractor. He brought a new injector and put it in. Tractor fired right up and had the power it is supposed to have. All good, except it is smoking terribly. In my limited knowledge it's like the one cylinder is not burning all the fuel. He's going to do a compression test on the cylinders tonight.