B2231 Kubota (23hp b series hst cab) - immediatelly looses power when I engage A/C. Any idea what could happen?

[Mat8791]

Hello I am operating b2 compact tractor (b2231 - 23HP) with original supercab by Kubota (including A/C) and la 424 front loader. The tractor is HST model. It has 420 operating hours. About 2 months ago I lost the a/c - reason was broken belt which gives power to A/C - I replaced it and it all became OK. However since some time I have serious problems with machine power. For example, I recenty purchased Peruzzo cross-fox implement for grass mulching and I noticed that my PTO speed keeps going down while machine has only 120cm width. And today was a real disaster. I was using a rock-burier implement which I use very often (also width is 125cm) and tractor really could not handle it at all, even with L settings and minimum speed machine was stalling all the time. Then I noticed, that when I dis-engaged the A/C, suddenly machine got a kick of power, and we are talking about a very big impact on PTO power. When I hit it on again, I got the PTO speed immediatelly going down from 540 to 400, 300 ... No idea what could cause that? All my filters are changed machine is after 400 hour service. Do You guys have any idea or advice what could happen? I also notice that with A/C engaged and PTO on, but rear implement RISED UP so no PTO load at all, when I turn the wheels I also hear engine revs going down...Last important observation - when I activate the AC, its barely working - it is little bit cold but for sure not like before (day and night experience)

 

[GreensvilleJay]

It sure sounds like the A/C compressor is putting a HUGE load on the engine.
Is there any way you can remove the A/C and run the tractor ? If so..is it 'normal' ?
Also while belt is off, see if you can hand spin the A/C compressor, then switch A/C on( to engage the clutch ) and try to spin the compressor. I'm thinking you should be able to spin it by hand, may be 'hard' but not 'tight' ??
A 'tight' compressor would give both symptoms..loss of engine power and 'low' cold. 'tight' as something in the compressor is binding, big time. It could be bearings or the 'vanes' or whatever is used inside to pump the freon round and round.
bottom line is it'll probably cost you a lot of cash....new compressor and discharge/flush/recharge.
I'm sure someone with A/C knowledge will know.

 

[Fordtech86]

First sign is the belt broke, sounds like compressor is locking up. With the tractor off can you spin the compressor hub by hand?

 

[DustyRusty]

The hub will turn easily if the clutch on the compressor isn't engaged. With the engine off, belt removed, ignition energized, and air conditioner set to cooling, try turning the compressor hub and pully. If it is difficult, the compressor is bad.

 

[Fordtech86]

The hub will turn easily if the clutch on the compressor isn't engaged. With the engine off, belt removed, ignition energized, and air conditioner set to cooling, try turning the compressor hub and pully. If it is difficult, the compressor is bad.

 

[RBsingl]

A still good (but not for long) AC compressor building too much head pressure will also put an excessive load on the engine. Debris loaded condenser, iced over evaporator, and/or a faulty pressure switch/sensor could all result in the compressor building far too much head pressure and loading the engine down.

As others stated, leave the A/C off and see if the tractor is producing normal power under a heavy load to ensure that it isn't an engine power development problem with a normally A/C system just being the straw that broke the camel's back.

Rodger

 

[Mat8791]

Dear all, the problem has been solved. I googled out the common HST Kubota problems related to loss of PTO power and everyone reported air and fuel as the first thing to check. However my tractor had full service by Kubota dealer recently and all filters has been checked. Kubota dealer suggested full tractor check by Kubota engineers including HP power measure, injectors measure which is very costly as tractor just passed 2 years warranty. I decided to investigate more on the google and Youtube. All reports about loss of power were coming from the lack of fuel under heavy load as the reason of stalling. I found this video :

and I did the same trick in my garage - just 15 minuts ago. Well, BOOM problem solved, works now like a beast... Honestly I did not saw as sewere problem as on this video - when I removed my fuel hose from the tank to the filter, the fuel pressure was quite good - for me was OK. But I decided to blow the air inside just to be sure (I heard bubbles in the tank for some seconds) and man, I imediatelly saw much stronger fuel flow. It was my mistake to look for the reason in the A/C. Now the A/C is fine and under full load, with heavy soil , engaging the A/C means going down from 560 RPM to 550 RPM - just 10 RPM less and tractor works like it should work again.

From my experience I highly recommend, that if You own any B-series or BX-series, just make sure that every bigger service or every 200H to do the same thing, it costs nothing takes few minutes and You are sure, that Your fuel output from the tank is correct - I will do it now every 200H in my machine ! Thanks for Your support guys and I wish You 1.000 hours of operating without any problem.

 

[MOOTS]

Dear all, the problem has been solved. I googled out the common HST Kubota problems related to loss of PTO power and everyone reported air and fuel as the first thing to check. However my tractor had full service by Kubota dealer recently and all filters has been checked. Kubota dealer suggested full tractor check by Kubota engineers including HP power measure, injectors measure which is very costly as tractor just passed 2 years warranty. I decided to investigate more on the google and Youtube. All reports about loss of power were coming from the lack of fuel under heavy load as the reason of stalling. I found this video :

and I did the same trick in my garage - just 15 minuts ago. Well, BOOM problem solved, works now like a beast... Honestly I did not saw as sewere problem as on this video - when I removed my fuel hose from the tank to the filter, the fuel pressure was quite good - for me was OK. But I decided to blow the air inside just to be sure (I heard bubbles in the tank for some seconds) and man, I imediatelly saw much stronger fuel flow. It was my mistake to look for the reason in the A/C. Now the A/C is fine and under full load, with heavy soil , engaging the A/C means going down from 560 RPM to 550 RPM - just 10 RPM less and tractor works like it should work again.

From my experience I highly recommend, that if You own any B-series or BX-series, just make sure that every bigger service or every 200H to do the same thing, it costs nothing takes few minutes and You are sure, that Your fuel output from the tank is correct - I will do it now every 200H in my machine ! Thanks for Your support guys and I wish You 1.000 hours of operating without any problem.

If that fixed it, you have trash in your tank. It will happen again.

 

[GreensvilleJay]

yeah... trash in tank.... BTDT..
The ONLY real way to FIX that problem is to remove the tank and properly clean it then inspect it to be 100% SURE it IS clean. When I had a similar 'loss of power' 3 years ago I had the 'fun' of removing the tank from my BX23S solo. It took about 3 hrs to FINALLY flush out a small, black chunk of plastic that had been semi floating around and around in the tank,NEVER saw it,even with LEDs in the tank !. Aside from breaking a $7 knob, it wasn't that bad of a job. Added a $store sink strainer to fuel input neck, about 650+ hrs since then, zero 'loss of power' problems.

 

[DustyRusty]

Considering that he has A/C he has a cab on the tractor. Removing the cab is the first thing that needs to be done to get to the tank. This isn't an easy task to do and could actually take more than a day to do if you haven't installed a cab before. I would want to have the cab installation manual before tackling that job. I have seen youtube videos of cabs being installed on the BX tractors, and they are quite complicated to assemble if you haven't done one before.

 

[Fordtech86]

Removing the cab is the first thing that needs to be done to get to the tank.

If the tank is under the hood, why would you need to remove the cab?

 

[DustyRusty]

because I was thinking that he had a BX, not a B. I am old and forgetful by the time that I read post #1 to the point that I read post #9 which mentioned the BX23S.

 

[GreensvilleJay]

hmm, the Cdn Kubota Partsfinder doesn't show a B2231 ! Maybe only available in Europe ??
No reason to NOT be able to lookup parts for it here though.
If the tank is under the seat, cab would have to come off....from the one picture I saw, THAT ain't going to be fun.

 

[DustyRusty]

The original poster is from Poland, so it must be a Polish model tractor. He needs to post some pictures of the tractor so we can visualize what it looks like in comparison to those that are/were available in North America, for similarities and differences.

 

[Fordtech86]

Coming soon

build.kubota-eu.com

 

[DustyRusty]

Sure wish that Kubota would offer North American buyers the same luxury as they offer in Europe.

• The suspension seat and optional air-suspended deluxe driver's seat offer a high level of comfort

BX Series - Groundcare

kuk.kubota-eu.com

 

[GreensvilleJay]

hmmm...
so a guy visiting here can't lookup or order parts for his 'foreign' machine ? seems silly...

can a guy order the Kubota seat using the part number ? if not, again seems silly....

 

[Jchonline]

If that fixed it, you have trash in your tank. It will happen again.

Yes was thinking the same thing. Next you need to drain and clean that tank. Good luck!