1997 Bobcat 873 Traction Loc Problem

[1ofU]

Havent posted in awhile on this forum ,, but my 873 has took on a problem started about 6 months ago and has gotten worse .. about 5 months ago .. what it first did was I ran the machine for 5 hrs straight doing dirt work ,, moving .grading etc . as I stopped to move back it wouldn't move like the parking brakes was on , I could move a inch forward and back but not move ,, I applied the parking brake a few times and it was fine ,, did the rest of the dirt work and was done ,, now it seems as soon as I run the machine and it get hot a hour or so , with out no warning it will do it again ,, as I come to a complete stop it will happen , but now I trip the brake pedal and it doesn't release it ,, I have to stop and let the machine set ,, the last time it did it the other day I let it set a couple of hours and it still didn't let the machine move when I started it back up , so I let it set over night and went down before leaving for work , it started right up , but it didn't move until I applied the brake pedal one time on and off the machine moved fine , took it up and put it into the shed , now all lights light up on the Bics fine ,, none or blinking just full light up .. I have no warnings or blicking on the Bics display screen .. , do you think I need to replace the traction lock solenoid as it is letting the cross bar slide down and setting the parking brakes .. ive only used the machine about 3 times since this problem has happen . the machine is a two owner machine , 4130 hrs, has never been beat to hell .. Thanks for any replies .. 1 of U Jess

 

[Tazza]

I wouldn't replace the solenoid just yet, i'd confirm it's bad or good first. There are 3 wires, black red and white.
Hood the black to ground, either red or white is hold, brush it past the +ve battery terminal and listen if the soienoid clunks. If not, it will hopefully be the hold coil, there should be a small spark. Try the other to see if it clunks.
When worked out, connect the hold coil to +12v then brush the pull over the +12v and it should lock the brake off. If it works, the solenoid is fine, it may be a bad relay in your fuse box.

 

[1ofU]

I wouldn't replace the solenoid just yet, i'd confirm it's bad or good first. There are 3 wires, black red and white.
Hood the black to ground, either red or white is hold, brush it past the +ve battery terminal and listen if the soienoid clunks. If not, it will hopefully be the hold coil, there should be a small spark. Try the other to see if it clunks.
When worked out, connect the hold coil to +12v then brush the pull over the +12v and it should lock the brake off. If it works, the solenoid is fine, it may be a bad relay in your fuse box.

Taz : Thanks for the reply ,, I also forgot to say that when it's cold and you first get in and start the motor with the lap bar up and lower it , you can hear the solenoid pop , and as well as setting the parking brake you can hear it pop ,, from the solenoid being activated ,, when it's warmed up /hot you will not hear the POP from the Solenoid .. Anyway I replaced the Solenoid , will run it in the morning letting the blue Loctite 242 setup before I run the machine and get it hot .. now if I still have the problem , I will address it again and go from there . just for people to know I buy my parts from All Skidsteers.com can get most things shipped in 2 days delivered .. the solenoid was 29.00 with shipping $36.61 the 21 yr old original part I don't mind replacing with new .. will post back with a update and see if the solenoid took care of the problem ,, replacing was very simple and straight forward , I always though that it pulled the cross bar up to set the brakes ,, no it pushes the cross bar down to release and it pops up to set the brakes . Thanks Again Jess

 

[1ofU]

Taz : Thanks for the reply ,, I also forgot to say that when it's cold and you first get in and start the motor with the lap bar up and lower it , you can hear the solenoid pop , and as well as setting the parking brake you can hear it pop ,, from the solenoid being activated ,, when it's warmed up /hot you will not hear the POP from the Solenoid .. Anyway I replaced the Solenoid , will run it in the morning letting the blue Loctite 242 setup before I run the machine and get it hot .. now if I still have the problem , I will address it again and go from there . just for people to know I buy my parts from All Skidsteers.com can get most things shipped in 2 days delivered .. the solenoid was 29.00 with shipping $36.61 the 21 yr old original part I don't mind replacing with new .. will post back with a update and see if the solenoid took care of the problem ,, replacing was very simple and straight forward , I always though that it pulled the cross bar up to set the brakes ,, no it pushes the cross bar down to release and it pops up to set the brakes . Thanks Again Jess

Update """" the solenoid did not take care of the problem ,, I ran it for a hour no problems shut it off and restarted it and it's locked up … the solenoid didn't pop ,,, I raised the cab , unbolted the solenoid and removed the crossbar , bolted back the solenoid down , started it and it didn't pop ,, but it moves normal because the cross bar is out ,, it just doesn't have a parking brake ,, all lights are lit up ,, have no warning flashes .. will call a Bobcat dealer and see what they have to say ,,, , I will pick up a new relay and install and go from there ,,anyway … the life and times of a Bobcat Owner ….. Jess

 

[Lowe.Buuck]

Update """" the solenoid did not take care of the problem ,, I ran it for a hour no problems shut it off and restarted it and it's locked up … the solenoid didn't pop ,,, I raised the cab , unbolted the solenoid and removed the crossbar , bolted back the solenoid down , started it and it didn't pop ,, but it moves normal because the cross bar is out ,, it just doesn't have a parking brake ,, all lights are lit up ,, have no warning flashes .. will call a Bobcat dealer and see what they have to say ,,, , I will pick up a new relay and install and go from there ,,anyway … the life and times of a Bobcat Owner ….. Jess

I looked at the wiring schematic for a 95 763. Yours maybe similar.
The BICS Controller provides power to the coil in the Brake Relay (which has wire colors Red, Black, White, Pink/White).
The white on the brake relay wire receives power from the Brake Fuse and then powers the pull coil on the Brake Solenoid.
The Brake Solenoid Pull Coil on mine is spec'd as 0.4-0.5 ohm white to black.
The Brake Solenoid Hold Coil is spec'd at 10-11 ohms.
I would check the following when it stops working:
1. Make sure you have power leaving the Brake Fuse. going to Red/White on the Brake Relay.
2. Make sure when you drop the seat bar the Brake Relay should close and provide power for a couple seconds on the white wire that goes to the pull coil on the Brake Solenoid. Easiest to check it at the solenoid while sitting in the seat.
3. Unplug the Brake Solenoid and check the resistance values on the Pull and Hold Coils

 

[1ofU]

I looked at the wiring schematic for a 95 763. Yours maybe similar.
The BICS Controller provides power to the coil in the Brake Relay (which has wire colors Red, Black, White, Pink/White).
The white on the brake relay wire receives power from the Brake Fuse and then powers the pull coil on the Brake Solenoid.
The Brake Solenoid Pull Coil on mine is spec'd as 0.4-0.5 ohm white to black.
The Brake Solenoid Hold Coil is spec'd at 10-11 ohms.
I would check the following when it stops working:
1. Make sure you have power leaving the Brake Fuse. going to Red/White on the Brake Relay.
2. Make sure when you drop the seat bar the Brake Relay should close and provide power for a couple seconds on the white wire that goes to the pull coil on the Brake Solenoid. Easiest to check it at the solenoid while sitting in the seat.
3. Unplug the Brake Solenoid and check the resistance values on the Pull and Hold Coils

Hello, Thanks for the reply ,, going to replace the relay with a new one,, then I will start checking the wires for ohms specs ,, in the mean time yesterday I removed the cross bar from the traction lock ,, I worked the bobcat for 3 hrs straight in the dirt , and it worked out good ,, just no parking park on machine ,, I will get if figured out ,, going to take a little more time and money .. Thanks Again for any Replies Jess