1991 B7100HST-D 4WD for $700

[chadlw]

Hi folks, new Kubota owner here...

Drug this home last weekend and curious on opinions. Previous owner used as back lot mower and last year the hydrostat starting making noise and slowing down. Drained oil, put fresh in and now won't move at all. He gave up. Now he's moving out of state and needed quick sale. I could see he didn't change the filter and I doubt touched the suction screen. The old battery would crank but engine just wouldn't start. I suspected old fuel and/or lines needed bleeding. I could feel the glow plugs working. He had a 1991 original dealer service manual (orange binder) and operators manual. He said it belonged to the rail road company he used to work for and served as a tug pulling a test cart. Years later he bought it from the company, added the 3 point and rotary cutter to mow his small back acreage. The kicker...it has 9300 hours and has sat outdoors it’s entire life. The old seat is shot. Front axle has forward/aft slop but everything else seemed tight. He claimed it ran great and had no issues other than the trans failing. I keep telling myself no new projects but I guess I have an addiction.

He took $700 for the tractor/cutter/manuals and threw in two dump carts. Also included new engine/air/hydro filters and half full jug of UDT2 fluid. The cutter is a Modern Ag Competitor 42" made in 2000. It has no wear and blades still look new. Very heavy duty. White cart is Agri-Fab 17 cuft and is straight with just some flaking paint. My favorite is the cute little Ingersoll-Case dump cart. It says Model C62 but I can't find any info on it. Sorry, I’m a Case fan too.

My dad thinks the tractor probably fully worn out and ready to part out. I’m hoping it still has a few more hours left in it.

First plan is trying to get it running this weekend…if the engine seems sound then I’ll pull the suction screen and go from there. I’m really hoping he didn’t run dry or overheat the pump causing damage. Praying it just needs the air bled out. This is about #5 in line on my project list so it may take some time to post any updates.

I would like to think I got a decent deal but I guess we’ll find out…opinions? Try to be nice, I’m not an idiot, just an optimistic tractor addict. This makes #8.

 

[North Idaho Wolfman]

All that for $700, you got a heck of a deal!
#1 get the motor started and then check the input to the hydro, I've heard several stories where people thought it was the hydro unit going out when it was actually the clutch was shot.

 

[ShaunRH]

If there is nothing fundamentally wrong with the engine (cracked block, bent/broken crank/journals, etc.) then you got a real steal. The engine can always be rebuilt. The HST can usually be repaired/fixed. You might have about $2K in front of you for investment, but it's over time so it generally is easier to take on the budget. Then you have a full working rig, ready to go for under $3K and that's pretty darned good for a diesel tractor of that size.

 

[chadlw]

Last night with a fresh battery and slight bleeding of the fuel pump the engine fired right up. Warmed up it only had a slight amount of blow-by. So that made me happy. Also confirmed the input shaft along with the rear PTO turns. I verified the mechanical linkage to the Hydro pump is operational. Or appears so. Lifted the rear tires and cycled fwd/reverse dozens of times with no tire movement or noise coming from the hydrostat. The 3-point arms do raise and lower. I guess next steps are checking pressure ports. Thanks for the input guys.

 

[85Hokie]

Last night with a fresh battery and slight bleeding of the fuel pump the engine fired right up. Warmed up it only had a slight amount of blow-by. So that made me happy. Also confirmed the input shaft along with the rear PTO turns. I verified the mechanical linkage to the Hydro pump is operational. Or appears so. Lifted the rear tires and cycled fwd/reverse dozens of times with no tire movement or noise coming from the hydrostat. The 3-point arms do raise and lower. I guess next steps are checking pressure ports. Thanks for the input guys.

they are going to come and arrest you! the tractor police......

great buy and have fun getting her back up and running at 100%

 

[chadlw]

Re: 1991 B7100HST-D 4WD for $700 - Update

You are right Hokie...especially after what I found last night. Probably get charged with theft now. ha ha.

With nasty oil drained I pulled these filters and looked like a plugged clothes dryer lint filter. Along with the garbage were fine metal particles. I had no hope for success. I washed the screens, blew air through the cooler lines and ran a rag into the filter holes with a final rinse of fresh oil. Borrowed a bucket of cheap Atwood’s 303 hydraulic fluid from my dad and installed a fresh Kubota spin on trans filter. I also noticed pushing the clutch all the way in did not disengage the drive shaft to the hydro. Minor adjustment and now the clutch works like it is supposed to. With the tractor on jack stands I fired up the engine and could hear the hydro pump making noise. All 4 wheels were turning! I couldn't believe it. Put it back on the ground and drove 1/4 mile to my parents and back. Tracked straight ahead and ran great. Plenty of power to climb hills even in high gear. No creep in neutral either. I'm impressed so far. Then drained the hot engine oil and replaced filter (it was as nasty as the hydraulic). Next will be changing axle oils and steering gear box. I’ll probably flush the hydrostat one more time with cheap oil before running the expensive Kubota oil and testing the tractor with some real work.

Unfortunately, when I push the clutch all the way in it rattles and has a slight vibration. I’m guessing the pilot bushing/bearing is out. But, being a hydrostat…easy fix is just leaving it engaged. LOL. I still can’t believe I got a running and driving Kubota for $700 + oil and filters. Seat is temporary, borrowed from a Massey mower. I will need a muffler, go through wiring and charging system and will get the lights going again. I am real happy about this now...Funny, my life with this little machine is starting at 9393...

 

[Billdog350]

Re: 1991 B7100HST-D 4WD for $700 - Update

Great news and congrats! Keep us posted as the repair continues. The flushing with cheap fluid sounds like a good idea. Go to SUDT2 as your final fill and you'll be SET!!!

 

[85Hokie]

Re: 1991 B7100HST-D 4WD for $700 - Update

You are right Hokie...especially after what I found last night. Probably get charged with theft now. ha ha.

With nasty oil drained I pulled these filters and looked like a plugged clothes dryer lint filter. Along with the garbage were fine metal particles. I had no hope for success. I washed the screens, blew air through the cooler lines and ran a rag into the filter holes with a final rinse of fresh oil. Borrowed a bucket of cheap Atwood’s 303 hydraulic fluid from my dad and installed a fresh Kubota spin on trans filter. I also noticed pushing the clutch all the way in did not disengage the drive shaft to the hydro. Minor adjustment and now the clutch works like it is supposed to. With the tractor on jack stands I fired up the engine and could hear the hydro pump making noise. All 4 wheels were turning! I couldn't believe it. Put it back on the ground and drove 1/4 mile to my parents and back. Tracked straight ahead and ran great. Plenty of power to climb hills even in high gear. No creep in neutral either. I'm impressed so far. Then drained the hot engine oil and replaced filter (it was as nasty as the hydraulic). Next will be changing axle oils and steering gear box. I’ll probably flush the hydrostat one more time with cheap oil before running the expensive Kubota oil and testing the tractor with some real work.

Unfortunately, when I push the clutch all the way in it rattles and has a slight vibration. I’m guessing the pilot bushing/bearing is out. But, being a hydrostat…easy fix is just leaving it engaged. LOL. I still can’t believe I got a running and driving Kubota for $700 + oil and filters. Seat is temporary, borrowed from a Massey mower. I will need a muffler, go through wiring and charging system and will get the lights going again. I am real happy about this now...Funny, my life with this little machine is starting at 9393...

Excellent news, and I am with Billdog, place that liquid gold (SUDT2) in there when it is all cleaned out and run her!!!

I'll tell the tractor police to leave you alone,cause you are spending $$$ and time getting her right.....