Kubota STW40 Hours meter

[tunin]

Hello all, I ended up buying another Kubota shrug, , it ws to good of a deal to pass. It is a German market model STW40, it was somewhat not compleate. it was apparantly in a workshop for restoration in Neu Ulm. It was not put together completely, parts missing and so on. imported in to my country, Herzegovina, been working on it for a while. Fixed most issues except two. Sourced lots of parts, it is a runner and a good tractor to the extent of my knowledge.

1. A/C does not work, checked the fuses, , belt, refrigerant, switches, ll checked lut, the fan blows but no cold air coming out. Any ideas?
2. the instrument cluster is not original, I purchased it on ebay, it fits, works ok but it is showing double the hours from what my tractor has in the documentation. is there a wy to fix this? It is annoying, but if i have to live with it, I guess I will have to,
3. Does anyone have the operators manual for this tractor, I received the service manual, scanned it and sent it to kubotabooksm uploaded now, but I do not have the operators manual.

in any case, thank you for any help.

regards,
tunin

 

[GreensvilleJay]

curious, is the hours meter digital or mechanical ?
if digital , to reprogram the 'computer's EEPROM' ,if mechanical, your can either spin it fast with a drill or physically 'flip digits' as needed.

 

[tunin]

curious, is the hours meter digital or mechanical ?
if digital , to reprogram the 'computer's EEPROM' ,if mechanical, your can either spin it fast with a drill or physically 'flip digits' as needed.

It is digital, tiny but bright.

 

[North Idaho Wolfman]

No way to reset the hours as they are in the memory of the panel.

This was the best I could find for the ops manual.

Operator's Manual for Kubota Tractor Models: STW34, STW37, STW40 | eBay

Find many great new & used options and get the best deals for Operator's Manual for Kubota Tractor Models: STW34, STW37, STW40 at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

I'll go through the WSM and see if I can give you anything to check with the A/C.

 

[tunin]

No way to reset the hours as they are in the memory of the panel.

This was the best I could find for the ops manual.

Operator's Manual for Kubota Tractor Models: STW34, STW37, STW40 | eBay

Find many great new & used options and get the best deals for Operator's Manual for Kubota Tractor Models: STW34, STW37, STW40 at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

I'll go through the WSM and see if I can give you anything to check with the A/C.

Thanks a million.

 

[tunin]

I did some more testing, I have pressure in the system on one of the valves but the pressure on rhe other valve is weak, that does not make sense, or does it?

 

[GreensvilleJay]

simple way...
If the hours meter gets pulses from the alternator , same as BX23S ( tacho signal), you simply feed a higher frequency into the 'computer' . Time will fly by and then reduce(slow down) the frequency generator to get the hours you want. Now if you overshoot ( go past ) the time you want...ooopsy, do it again.

harder way...
The other way is to reset the EEPROM locations that store the 'hours data'. This takes some low level computer knowledge, a computer with CANbus interface and some coding skills.

Either of these will change the hour meter, both require skills that some may not have though.

 

[North Idaho Wolfman]

I did some more testing, I have pressure in the system on one of the valves but the pressure on rhe other valve is weak, that does not make sense, or does it?

If it was running that would be exactly right.
You have a high side and a low side.
What pressures did you see?

 

[tunin]

simple way...
If the hours meter gets pulses from the alternator , same as BX23S ( tacho signal), you simply feed a higher frequency into the 'computer' . Time will fly by and then reduce(slow down) the frequency generator to get the hours you want. Now if you overshoot ( go past ) the time you want...ooopsy, do it again.

harder way...
The other way is to reset the EEPROM locations that store the 'hours data'. This takes some low level computer knowledge, a computer with CANbus interface and some coding skills.

Either of these will change the hour meter, both require skills that some may not have though.

Thank you, I ws looking in to taking the eprom out and having someone online do the magic.

 

[tunin]

If it was running that would be exactly right.
You have a high side and a low side.
What pressures did you see?

No, actually it was not running, I called a friend that has a automotive charging unit for refrigerants, the service manual Shows R134A 630-730 grams, he said that that is to big of a gap of 100 grams… that I need to be more precise? Any idea?

 

[tunin]

I fixed the a/c. the valve on the filter head was having an issue.

 

[tunin]

Does anyone how to calculate front back tires sizes on a 4 x4 tractor? I need to narrow it down. Bit, the back tires are 320 70 r20, I would like to go with 280, wht combo for front tires do I need to. Go with? My old vineyards are quite narrow, this the change.