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Bobcat t300 code 05-15

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
I need help. Changed a drive motor. Installed new hydraulic charge pump. Installed new control valve plus coil. Installed new main controller. Installed new case drain filter. New hydraulic fluid.
Brakes are locked. No bucket lift or tilt.
All lights come on. Start engine and runs a few minutes then shuts down. Belt is tight and pully key is not sheared. New battery. All fuses good.
Only thing i have noticed is the green wire from main controller supplying voltage to valve coil is 5 volts. I thought it was suppose yo be 12 volts in order to unlock brakes. Need help. Jerry
 

Txhayseed

Senior Member
Joined
Dec 23, 2019
Messages
610
Location
Texas
Jerry , did you loose a drive motor and that why you changed it? Sounds like you changed a lot of parts. Did you change them all out once due to the low charge pressure code or over time ?
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
Jerry , did you loose a drive motor and that why you changed it? Sounds like you changed a lot of parts. Did you change them all out once due to the low charge pressure code or over time ?
Had a drive motor start acting up on right hand track. Changed it out. Replaced case drain filter and refilled with fluid. Then other codes kept showing up everytime one thing was fixed. Had bobcat come out. He said hydraulic pump was the problem. So i installed a new one and once more refilled with fluid. Then brakes were locked and bobcat came back out and said main controller was bad so they put a new one one. Tracks turned. Few days later code 05-15 has now popped up. I checked voltage at brake lock soleniod and it showed 4.7 volts. I thought it was surpose to be 12 volts? Brake valve soleniod was replaced by bobcat. He them come back out. I was to be here when they came. The tech dropped by while i was away. He reported he didn't crank it up. Just opened the fluid reservoir plug on top of tank and stuck a magnet down inside, claiming it had metal all over it. And the left sending me a text and a bill for another $170 dollars. I got home not believing and put my own magnet down inside. Got a little slugg by way of raking magnet around on the bottom of tank. No metal pieces at all. Checked case drain filter. No metal at all. So trying to find problem myself. Tracks are locked. All lights come on. Cranks and runs a few minutes the hydraulic light flashes and shut down occurs. I listed all new things so as to help make making a suggestion better. Oh yes belt is good and key on pulley is not sheared. Have checked. Im hoping i am right in thanking brake valve soleniod voltage should be 12 volts not 4.7 volts. If 12 volts is correct i could jump 12 volts to coil and see if tracks unlock. If so do you think the new main controller could be bad? Wire running from it to coil is good. Jerry
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
Txhayseed, you got any advice what to check?
Is there a screen someplace other than case drain filter, i should check that might be blocked on bobcat t300 2004 model? Also arn't I'm correct in thinking brake valve lock soleniod coil requires 12 volts? I'm showing 4.7 volts supplied by green wire coming from main controller which is new installed by bobcat rep. Jerry
 

Txhayseed

Senior Member
Joined
Dec 23, 2019
Messages
610
Location
Texas
Did you flush the system through out or just drain it and change filters ? Not sure if you inspected your failed drive motor to see what failed internally. Back to back hydraulic component failures are usually contamination related. It does not take much inside the system to do major damage, plug up valves etc. parking brake would not have anything to do with hydraulic pressure. It’s electromagnetic. You can take it loose or jump it but you still have to deal the BIS that’s what actually lets your hydraulic system unlock. I would take a serious look inside your filter. Cut in open and check your system for contamination. That’s where I would start. Sounds like you definitely have a common failure point
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
Did you flush the system through out or just drain it and change filters ? Not sure if you inspected your failed drive motor to see what failed internally. Back to back hydraulic component failures are usually contamination related. It does not take much inside the system to do major damage, plug up valves etc. parking brake would not have anything to do with hydraulic pressure. It’s electromagnetic. You can take it loose or jump it but you still have to deal the BIS that’s what actually lets your hydraulic system unlock. I would take a serious look inside your filter. Cut in open and check your system for contamination. That’s where I would start. Sounds like you definitely have a common failure point
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
Think you for your reply and suggestions..i refilled the reservoir tank with new hrdraulic oil and cranked the engine with one line open for flushing. Did this three times in a row. Have found no metal in filters.
I do believe just today i may have found two problems. The speed sensor at flywheel was broken. I removed it and crap was all over its probe end. Plus with a light and mirrow could see the flywheel had become rusty and dirty. According to what i have read. This can cause tracks and loader arms and tilt to lock up. Another thing i removed the valve lock soleniod and doing an ohm check of coil. Found it to read 9 ohms. Talked to a bobcat mechanic and he said it should only read while being off stim .9 ohms. He said that the reading i got was to high and soleniod was bad.
While i had it off i connected 12 volts to red positive wire and ground to black wire. Then using a screwdriver found it would not act as a magnet when sticking it inside. So believe the coil is bad as well. I hope i am lucky with what i have found and hopefully once replaced i will be fine for now. Any other suggestions would be greatly appreciated. It all means alot to me. Jerry Hill
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
Well today rechecked coil while off machine in my shop. Connected a hot 12 volt battery to it momentarily and it attracts a screwdiver like a magnet. So it is good.
I found the speed sensor on flywheel was broken in the plastic threads and the signal end was dirty and rusty as could be. After checking bobcat parts pricing found tax and all they wanted 80 bucks. Found the same on ebay out of Texas for 30 bucks free shipping. So with a savings like that, I'm willing to wait for it to arrive.
Based on what i have read. I believe the speed sensor is going to be my problem on brake valve soleniod lock of tracks and arm lift/tilt. My speed sensor was not shorted as i did an ohm test. But being so dirty and the flywheel as well. It had my new controller throwing crazy codes or wrong signals to brake valve lock. It being broken probably had the sensor back to far from flywheel in order to send to the controller the correct rpm reading. Jerry Hill
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
Well today rechecked coil while off machine in my shop. Connected a hot 12 volt battery to it and it attracts a screwdiver like a magnet. So it is good.
I found the speed sensor on flywheel was broken in the plastic threads and the signal end was dirty and rusty as could be. After checking bobcat parts pricing found tax and all they wanted 80 bucks. Found the same on ebay out of Texas for 30 bucks free shipping. So with a saving like that willing to wait for it to arrive.
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
Txhayseed
Thank you for your help.
Today i pulled new brake valve out and coil. Tested new valve and it was fine. No slug on screen of particles. Coil is new and still good. Checked voltage at pigtail red wire only had 5 volts with switch on. Shouldn't it be receiving 12 volts from main controller? I checked green wire top right on back of main controller to see if it was shorted of broken. It was good. I cut green wire out of main controller to test its output voltage to brake valve coil and voltage was 5 volts there as well. Have checked ground and it is good.
Traction relay checks good in test and/or swapping. 12 volts is present at relay.
I just do understand why brakes are nof unlocking at this point.
Do you think pressure switch is bad. As soon as i can find a T fitting. I plan to pressure test prior to pressure switch. I have a 6000 pound oil gauge.
I have been unable to find any line blockage. Hydraulic oil is as clean as can be. Every place i have checked its clean and no trash found including filters.
I just believe it has to be electrical problem. Please help. Jerry
 

KSSS

Senior Member
Joined
Feb 27, 2005
Messages
4,319
Location
Idaho
Occupation
excavation
If the Ohms are that high, I also believe you have an electrical problem. There may a wire corroded somewhere that is increasing the resistance. Just had a similar problem on my CX160. After a week of searching found the wire going from battery to the console had been spliced 7 times by previous owner and it would allow some current but the ohms were off the chart. Replaced that section of wire and all is good. Perhaps you have similar problem
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
Txhayseed
Thank you for your help.
Today i pulled new brake valve out and coil. Tested new valve and it was fine. No slug on screen of particles. Coil is new and still good. Checked voltage at pigtail red wire only had 5 volts with switch on. Shouldn't it be receiving 12 volts from main controller? I checked green wire top right on back of main controller to see if it was shorted of broken. It was good. I cut green wire out of main controller to test its output voltage to brake valve coil and voltage was 5 volts there as well. Have checked ground and it is good.
Traction relay checks good in test and/or swapping. 12 volts is present at relay.
I just do understand why brakes are nof unlocking at this point.
Do you think pressure switch is bad. As soon as i can find a T fitting. I plan to pressure test prior to pressure switch. I have a 6000 pound oil gauge.
I have been unable to find any line blockage. Hydraulic oil is as clean as can be. Every place i have checked its clean and no trash found including filters.
I just believe it has to be electrical problem. Please help. Jerry
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
TX HAYSEED,
Have been all over checking t300. Got all codes taken care of but 05-14. Got in machine to crank it up. Started cranking and started hearing a high pitch squeal coming from the pulley side of machine. 05-14 being low hydraulic pressure. Just as the bobcat shut down. Code changed to 05-15. Believe 04-15 code is my problem. Hopefully the drive belt is slipping causing my last problem. Sure seems like it. Got a new one on order. Will get back. Thanks for all the help. Jerry
 

jerry hill

Active Member
Joined
May 17, 2018
Messages
28
Location
wilsonville alabama
TXHAYSEED. Update for everyone on my T300 Bobcat with 04-15 code. Have checked everything in the world in order to fix my machine. Sensors, pressure switch, traction lock valve with soleniod, case drain filter, hydraulic main filter. You name it i have done that. I had several problems to begin with starting with a drive motor acting up and throwing a code. Replaced it then checked pressure and the hydraulic pump had a problem, probably caused by the drive motor. Replaced pump flushed the hydraulic system out three times with new oil.
Then 04-15 code came up and then switched to 05-15 right before machine shut down. So instead of devoting all my attention to 05-15, I started researching problems associated with 04-15 code. Even tho 05-15 code is related to hydrsulic pressure it also means that bobcat has gone into shutdown mode. Many times others kept saying hydraulic drive belt bad or slipping. My belt looked good and only had a little play in it, but during cranking it up, i did think i heard the belt squeal a little. So today removed what was necessary and tightened the belt good. Put everything back together and started the machine. No more codes and tracks rotate forward and backwards and arms raise and bucket tilts. I did say a prayer before hitting the starting switch, because this has all but driven me crazy. So I'm sure that helped as well.
So guess the new hydraulic pump requires more effort to turn it up to maximum pressure as needed, compared to the old hydraulic pump.
Would like to think TXHAYSEED and a few others for your suggestions in trying to help me. I never like something whipping me. I hate giving up. Jerry Hill
 

JLELECTRIC

New Member
Joined
Jan 1, 2021
Messages
4
Location
North Carolina
Occupation
Electrician
TXHAYSEED. Update for everyone on my T300 Bobcat with 04-15 code. Have checked everything in the world in order to fix my machine. Sensors, pressure switch, traction lock valve with soleniod, case drain filter, hydraulic main filter. You name it i have done that. I had several problems to begin with starting with a drive motor acting up and throwing a code. Replaced it then checked pressure and the hydraulic pump had a problem, probably caused by the drive motor. Replaced pump flushed the hydraulic system out three times with new oil.
Then 04-15 code came up and then switched to 05-15 right before machine shut down. So instead of devoting all my attention to 05-15, I started researching problems associated with 04-15 code. Even tho 05-15 code is related to hydrsulic pressure it also means that bobcat has gone into shutdown mode. Many times others kept saying hydraulic drive belt bad or slipping. My belt looked good and only had a little play in it, but during cranking it up, i did think i heard the belt squeal a little. So today removed what was necessary and tightened the belt good. Put everything back together and started the machine. No more codes and tracks rotate forward and backwards and arms raise and bucket tilts. I did say a prayer before hitting the starting switch, because this has all but driven me crazy. So I'm sure that helped as well.
So guess the new hydraulic pump requires more effort to turn it up to maximum pressure as needed, compared to the old hydraulic pump.
Would like to think TXHAYSEED and a few others for your suggestions in trying to help me. I never like something whipping me. I hate giving up. Jerry Hill
I have had the same issue with my T300. My belt looks good, but I have a little play in the belt. How did you tighten the belt with this type tensioner. I have moved the stop forward to idler arm and tightened. The spring is tight.
 
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