B26 safety kill problem

[Jon Sanders]

Greetings - new member here.
I searched for this subject but don't find much on the B26.
I bought my 2010 B26 TLB HST in April 2018, and really love it. I grew up driving orange tractors (Allis WD/WD45) as a kid so the color is very nostalgic for me.
Since it came to me with 1150 hrs, I have had a few things to maintain, so I ordered the full shop manual which should arrive next week.

Meantime I wanted to ask if anyone knows the specifics of the safety kill circuit for this specific model. Last week while preparing to dump a bucket of dirt into a trailer, the kill circuit activated when I pressed the hydro pedal. After that it behaved like one of the seat switches (presence & direction) was open. I tested continuity on them and they are good. Are there any other switches on this model? Or do I need to look for broken wire?

Additional info - starts, runs, hydraulics work. Fuel shutoff solenoid activates when pedal is pressed.

tia

 

[mickeyd]

Welcome to the OTT forum Jon. You came to the right place to answers.

You did the right thing by ordering a Work Shop Manual (WSM) as it has an electrical schematic.

You can go to Kubota Illustrated Parts List at: https://apps.kubotausa.com/illustrated-parts/ to get part numbers of the safety switches.

 

[SAITCHO]

On my B26, I bypassed both the presence and direction switches. There is a switch on the PTO lever also. The only issue I had on mine is the HST pedal switch. I had to slightly play with the pedal while the key was on the start position to find the sweet spot to get it to start. Do this simple test, place it in low gear, lift the wheels up in the air with the outriggers and press the HST pedal forward and check if the wheels keep on turning when you release it. Do the same in reverse. If the wheels keep on turning you need to adjust the pedal. Go on the right side of the machine and play with the pedal with your hand and look under the machine, you will see the switch in there and the adjustment screw. Make sure you also grease the pivot in there. On my tractor I had to dismantle a few linkage parts, clean them, grease them and put them back on to fix the issue.

 

[Jon Sanders]

Thanks for the feedback - if there is a 3rd switch on the PTO control I will track that down. The engine starts and runs without issue, so I don't think the pedal is an issue - it failed right in the middle of loading a scoop of dirt, so maybe something was bounced.

However, if the seat switches are indicating that I am in the seat and facing forward, engaging the PTO would not violate safety and should not kill the engine.

I need to find the home point of the kill circuit to add a temporary jumper to test the wiring harness. Guess I will wait on the manual.

Thanks again - glad to be a part of the Orange community...

 

[CurtisC]

Jon, you didn't say but assume you checked the weight setting on the presence switch? If the weight suspension knob is set too high it can work OK until you lean forward or take any weight at all off the seat allowing a slight seat rise and contact is broken. Also make sure seat direction switch stop tab on the seat doesn't ride over the seat direction switch arm. Happened to me the other day after working the hoe with tractor facing up a steep incline. After spinning the seat around the tractor died when I hit the HST pedal. After looking at it I found that if I pulled back on the seat while rotating it forward I could get the tab to ride over the switch arm. Other than PTO safety interlocks the seat switches are the only other safety switch circuits I'm aware of.

 

[Jetech]

I was having an issue with my 2601 seat switch, I found the bracket holding the switch was bent down slightly. I bent it back in place by hand and haven't had anymore trouble. You may want to look at the bracket.

 

[Dave_eng]

Jon
Check your private messages

Dave

 

[Jon Sanders]

Resolved - I think.

The night it failed I was offsite and I pulled the plug on the seat switch and stuck a piece of wire in both sides to jumper it but it still would fault out. (The good thing was that I learned how to get my tractor back onto the trailer using the backhoe.)

After I got it home I pulled the switch out and tested it for continuity and it was good, so I presumed that the problem was elsewhere.

Tonight I removed the seat switch again, connected it to the harness and held it in my hand and voila! Back in business.

Not sure whether I did a poor job of jumpering in the field, or whether the seat direction switch was helping with the problem, because it also acts up quite a bit. I don't want to bypass safety circuits but they are not robust enough to suit me.

Thanks for all of the helpful input! Hope to return the favor...