I'm new to this forum, however I read on here a lot. My 2001 Bobcat 864 has me stumped so I'm posting on here in hopes that someone can help. I have had an intermittent seat bar sensor issue (the traction lock would randomly lock up like I raised the seat bar). I ended up getting a new senor and just taped the magnet in place for the time being. Well the machine ran for about 6 more hours and now I'm back to having my traction lock randomly locking up. Then yesterday I couldn't even get the traction lock to turn off. I had to hit traction lock override and just park it on the job site. I've also had some random other sensors acting up suddenly. The low hydraulic fluid pressure light started coming on and would turn the machine off. So I unplugged that sensor under the cab and it stopped shutting off the machine. I'm 99% sure I don't have a hydraulic pressure issue... Its all electrical. Then yesterday my low oil pressure light started coming on and turning off the machine too. I'm starting to wonder why I'm having so many random electrical issues. I've only owned this machine for about 5 months and have put on a little less than 60 hours. It runs great mechanically but has these electrical issues. Not sure where to start... I've raised the cab and traced wires but nothing looks damaged. Fuses were all good too. Anyone have any ideas or a way to fix the traction Lock?
Traction Lock stuck on and Other Electrical Issues
- Thread starter TheJerm
- Start date
I'll have to check voltage on the alternator. But there are no other electrical issues besides the Oil pressure sensor, the hydraulic pressure sensor and traction lock/seat bar sensor acting up. Oh and the heater has never worked I am starting to wonder if it is the computer. So Friday nothing I did would unlock the traction lock system and the low oil pressure light was coming on and shutting down the machine. I finally gave up and parked the machine. Today I show up to work on it and it runs fine. Traction lock turns off and no oil pressure light. After about 45 minutes to an hour the machine starts acting up again with the same issues. I raised the cab, checked all my wires again. Cleaned some of the connectors, cleaned my relay and fuse connections, swapped the traction lock relay. Nothing I did would unlock the traction lock. I finally gave up and figured maybe I'll try replacing the traction lock sensor again and maybe the pig tail. Other than that I am stumped.
Found this post.... https://talk.newagtalk.com/forums/thread-view.asp?tid=519917&DisplayType=flat&setCookie=1......... He was having almost the same issue and it was the "Brain box"/computer
bobbie-g
Well-known member
- Joined
- Mar 15, 2004
- Messages
- 577
Presumably you have a G series machine from your description of the issues. I don't know exactly how a G series would act, but on the earlier machines (BICS only, no computer), the traction lock solenoid could be removed (retracted manually) so the machine could be driven. Unsure if a G series would put hydro power to the drive motors if it thought the lap bar was up and/or the PTO button was not pressed. You might try just easing it forward or backward when it acts up and see if the drive motors are pushing against the traction lock solenoid. The solenoid will be under the cab, between your feet. On an older machine (751), I pulled the housing loose, pushed the solenoid pin upward against the spring, and somehow used a hose clamp to hold it up and out of the "cogs" where it locks the drive chains. That way I could drive it without getting dirt into the chain case. I think my problem was much simpler: a defective "emergency brake" switch. I've never used that switch again since that day.
---Bobbie-G
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The 864 being a track machine probably has a different traction lock system. I know the newer machines the sensors are a lower voltage system that is operated by the computer. I believe it’s 4.5 volts if I remember correctly. Most machines the computer is below the cab along the side. I would start disconnecting plugs hitting them with contact cleaner and dielectric grease. Sounds like a bad connection somewherePresumably you have a G series machine from your description of the issues. I don't know exactly how a G series would act, but on the earlier machines (BICS only, no computer), the traction lock solenoid could be removed (retracted manually) so the machine could be driven. Unsure if a G series would put hydro power to the drive motors if it thought the lap bar was up and/or the PTO button was not pressed. You might try just easing it forward or backward when it acts up and see if the drive motors are pushing against the traction lock solenoid. The solenoid will be under the cab, between your feet. On an older machine (751), I pulled the housing loose, pushed the solenoid pin upward against the spring, and somehow used a hose clamp to hold it up and out of the "cogs" where it locks the drive chains. That way I could drive it without getting dirt into the chain case. I think my problem was much simpler: a defective "emergency brake" switch. I've never used that switch again since that day.
Thanks for your reply's! I am almost sure I have a G series. Its a 2000 864. I cleaned all the connections I could find following the seat bar sensor back but it goes into the harness and it gets too hard to trace (since the harness is wrapped). I didn't open up the area with the computer. I know its down by your left leg. Should I start looking in there and cleaning connections?
My machine has a traction lock override button. It allows the machine to move forward and back but won't let you operate the bucket. Is the traction lock solenoid the same as the little emergency brake/push button down by your feet? I would really like to ditch the entire system if it was possible. Just need to get my work done and this thing is driving me crazy.Presumably you have a G series machine from your description of the issues. I don't know exactly how a G series would act, but on the earlier machines (BICS only, no computer), the traction lock solenoid could be removed (retracted manually) so the machine could be driven. Unsure if a G series would put hydro power to the drive motors if it thought the lap bar was up and/or the PTO button was not pressed. You might try just easing it forward or backward when it acts up and see if the drive motors are pushing against the traction lock solenoid. The solenoid will be under the cab, between your feet. On an older machine (751), I pulled the housing loose, pushed the solenoid pin upward against the spring, and somehow used a hose clamp to hold it up and out of the "cogs" where it locks the drive chains. That way I could drive it without getting dirt into the chain case. I think my problem was much simpler: a defective "emergency brake" switch. I've never used that switch again since that day.
I'm wondering if the issue could be the brake solenoid. If it's weak, it would pull and hold in place. Hit a bump or it warms up, it could let go. The traction overide button will make it snap back for the hold coil to keep it there.
Just a possibility.
Possible but I think on track drive it’s just a valve not pulling a pin like a wheeled machine
Stopped by Bobcat today and spoke to their service guy. He told me that it sounds like an alternator issue. I also picked up a new hydraulic pressure sender. Got to the job site and fired up the machine. Sure enough the seat bar sensor worked fine but the hydraulic pressure light was on. Flipped up the cab and swapped the sender and the hydraulic pressure light went off. Ran the machine without any issues for about 2-3 hours. Suddenly the seat bar sensor started acting up and a few minutes later the hydraulic pressure light was on again. Battery voltage was at about 12.5 and alternator was strong at 14.5v. (Didn't think it was my alternator because the seat bar light will flicker when the machine is off with the key turned to start). However, I got excited because while probing I wiggled the ground strap from the engine to the frame and it made the seat sensor light click on and off. Thinking I found the problem, I cleaned that ground up real nice.... AND no luck... couldn't get the seat bar sensor to engage and unlock the hydraulics at all. So parked the machine.
Part of me thinks it could be the main control module for the machine... But the strange thing is how it seems heat related. Control module isn't anywhere near heat. Today it was only about 15 degrees and it seemed to run for a little longer than usual. I bought this machine back in June 2017... my battery has a 2017 sticker on it and battery voltage is normal. Really stumped
Farmshop - you got me there, i had in my head it was a regular skidder, and not a tracked machine....
I wouldn't condem the controller just yet, you did say you wiggled the ground wire and the seat sensor light flicked, i'd look into the harness around this ground wire. It may have moved the main harness enough to disturb the bad connection.
As for heat, don't forget that electronics generate heat, so it may not be near the engine, but it will heat up somewhat, so it could be issues with solder joints opening up as the module heats up.
Thanks Tazza... Appreciate you helping me through this. Its one of those issues thats probably right in front of me. This electrical system isn't that complex. Didn't make it down to the work site today due to snow. Plan to clean up my battery terminals and replace a ground strap that had some frayed wires.. I think it was still making a good connection but you never know. Going to keep working through it.
No luck again today. Ran the machine for an hour and a half.... Started acting up (Seat bar sensor wouldn't engage, low hydraulic fluid sensor coming on). Cleaned my grounds and connections around the battery... No change. I pulled my battery and had the auto parts store test it. Tested fine (12.4 volts). Kind of running out of ideas here.
Check the voltage going to the affected components. If you can find your traction lock solenoid you could apply voltage to it to make it move. Also the hydraulic sensor should have voltage running to it. I believe it’s around 4 volts. If that sensor isn’t working it could be the computer doesn’t think the machine is running. I’d see if your dealer has a “test” computer they can swap in to rule out the controller
My issue is consistent.. Machine runs for around the first hour without any issues. Then the seat bar sensor starts acting up followed by hydraulic and oil pressure sensors. Let it sit for 4 hours and the machine runs fine again. I have 3.4 volts at the seat bar even when acting up. Seat sensor and hydraulic pressure sensors are new. Battery tested good, alternator is good. Cleaned up all grounds and no frayed wires are present. Fuses and relays are good. Cleaned connections. I don't know what else it could be other than the control/computer. Going to see if I can find one to swap in. Either that I might have to take the machine to Bobcat because I'm in middle of an important project and can't get it done with this problem. I'll keep everyone posted once I figure it out.
Resolved!!!! It was my computer. After trying everything else I could think of, I found a computer for sale for $580. Figured I would give it a shot and it fixed my issue
It sucks it came to that but at least it’s fixed. I am always glad I work with a knowledgeable dealer when it comes to these kind of problems
