lawdog8234
New member
- Joined
- Apr 3, 2010
- Messages
- 1
My 753 moves about 20 feet then wheel lock engages. I turn key off and restart then move 20 feet and again wheel lock engages. Can any one help with my problem?
753 bobcat
- Thread starter lawdog8234
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komatsu
New member
had the same problem bobcat told me to check the altnater,the other thing is hyd level but my machine was sitting for awhile .
gatractorman
Silver Member
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- Jan 27, 2002
- Messages
- 183
- Location
- Cleveland GA
- Tractor
- varies never keep one long enough to post here lol
It can be a myriad of things, do you have any codes or flashing lights? I'm thinking about the brake lock solenoid it has a pull-in circuit (which is stronger) and a hold-in circuit it may be the hold circuit has failed.
Also do check the alternator and belt like the other poster said, I did run into 1 that had a loose belt that evidently was causing voltage spikes that the electrical system did not like.
Also do check the alternator and belt like the other poster said, I did run into 1 that had a loose belt that evidently was causing voltage spikes that the electrical system did not like.
some zilch
Gold Member
- Joined
- Sep 19, 2008
- Messages
- 468
i would guess the brake lock plunger is falling back down and engaging the brake discs.
Cannon
New member
The BICS & the BOSS can be a bear to tear into so I'd back track from the easiest troubleshooting steps. Hopefully it's just an intermittent connection.
Reiterating what you describe: Turn the key; pause, till hear the lock drop; start; :20 sec later jolts to a stop (no movement AND no hydraulics to the lift arms or tilt cylinder).
1. Grounding/Overload: System works off a negative ground with 8 fuses protecting just the electrical system from overload=ask is there an electrical overload.
a. Fuses. Have some 10, 15, & 25 amp fuses handy and swap out each fuse in the two fuse boxes Brake works off a 25 amp fuse. Below is the two fuse boxes, and their fuse ratings. (There also should be a decal inside the door showing fuse sizes). Note: I could be as simple as the spade connectors in the fuse box have expanded=loose fuse seating.
Message - TractorByNet.com Photo Gallery
b.Battery Condition. Loose/grounding inadvertently to include the heavy gauge wire connections e.g.: Alternator, Starter, & Ground. (my holding bracket busted 2 yrs ago & I haven't needed to replace/refasten since confined in such a narrow space between the chassis & blower cover.
c. Starter. Kinda not thinking it's this... but if want, you can remove, inspect, and test. Issues to look for would include:broken/burned insulation; loose connections; open or grounded circuit, etc... (read disassembly & ammeter required).
d. Instrument Panel. Inspect the wire harnesses behind the panel.
e. Relay Switches. (Beneath the Air Cleaner) Those are for the starter, switch power, glow plug, brake, and shutdown. (Mine only has four since I don't have BOSS).
f. Parking Brake. Not to be insulting, but the parking brake pedal has an electrical sensor/harness. I would assume it's NOT the mechanical linkage that leads from the pedal to the inside of the machine below the right joystick/chain case-but the switch/harness itself.
g. Seat Bar Sensor.
-Inspect the wire trace along the left side of the cab and includes a two pin harness between the bar and the instrument panel. When the harnesses was loose I got stuck in 55 mph traffic (wasn't any traffic when I decided to turn around!!) took :10 min of fright to figure that one out.... The cause was I had 'herked & jerked the machine too hard during turns on the asphalt, causing it to disconnect.
-Inspect the sensor assembly where it attaches to the seat bar. Especially where the sensor and magnet make contact, mine is located on the left side of the seat bar.
-Inspect the contact between the "vertical arms" (2"+ white nylon plastic for lack of a better description) and Bar that depress when the bar is down to ensure the sensor is staying engaged - I've always assumed that someone in the past that didn't have their cab bolted down and the contact between the two separated would cause a sudden stop.
h. Seat Sensor.
-Too much debris or other objects stopping contact. I had to mount my cheater bar to the inside cab roof since it would roll under the seat at times and shut down the machine.
-Connectivity/Age. I had to raise the cab and clean up underneath the seat since the seat wouldn't adjust anymore to include doing maintenance on the seat rails, seat springs, and most importantly the sensor (sensor is surrounded by magnet collar). I found the sensor had become corroded to the point of taking a wire wheel brush to ensure connectivity.(also the sensor harness is connected under the cab).
i. Traction Lock Stop. If/when the above doesn't pan out, I can provide details on. It includes minor chain case work and inspecting the solenoid.
Good luck 'LD, & Let us know how it turns out.
Reiterating what you describe: Turn the key; pause, till hear the lock drop; start; :20 sec later jolts to a stop (no movement AND no hydraulics to the lift arms or tilt cylinder).
1. Grounding/Overload: System works off a negative ground with 8 fuses protecting just the electrical system from overload=ask is there an electrical overload.
a. Fuses. Have some 10, 15, & 25 amp fuses handy and swap out each fuse in the two fuse boxes Brake works off a 25 amp fuse. Below is the two fuse boxes, and their fuse ratings. (There also should be a decal inside the door showing fuse sizes). Note: I could be as simple as the spade connectors in the fuse box have expanded=loose fuse seating.
Message - TractorByNet.com Photo Gallery
b.Battery Condition. Loose/grounding inadvertently to include the heavy gauge wire connections e.g.: Alternator, Starter, & Ground. (my holding bracket busted 2 yrs ago & I haven't needed to replace/refasten since confined in such a narrow space between the chassis & blower cover.
c. Starter. Kinda not thinking it's this... but if want, you can remove, inspect, and test. Issues to look for would include:broken/burned insulation; loose connections; open or grounded circuit, etc... (read disassembly & ammeter required).
d. Instrument Panel. Inspect the wire harnesses behind the panel.
e. Relay Switches. (Beneath the Air Cleaner) Those are for the starter, switch power, glow plug, brake, and shutdown. (Mine only has four since I don't have BOSS).
f. Parking Brake. Not to be insulting, but the parking brake pedal has an electrical sensor/harness. I would assume it's NOT the mechanical linkage that leads from the pedal to the inside of the machine below the right joystick/chain case-but the switch/harness itself.
g. Seat Bar Sensor.
-Inspect the wire trace along the left side of the cab and includes a two pin harness between the bar and the instrument panel. When the harnesses was loose I got stuck in 55 mph traffic (wasn't any traffic when I decided to turn around!!) took :10 min of fright to figure that one out.... The cause was I had 'herked & jerked the machine too hard during turns on the asphalt, causing it to disconnect.
-Inspect the sensor assembly where it attaches to the seat bar. Especially where the sensor and magnet make contact, mine is located on the left side of the seat bar.
-Inspect the contact between the "vertical arms" (2"+ white nylon plastic for lack of a better description) and Bar that depress when the bar is down to ensure the sensor is staying engaged - I've always assumed that someone in the past that didn't have their cab bolted down and the contact between the two separated would cause a sudden stop.
h. Seat Sensor.
-Too much debris or other objects stopping contact. I had to mount my cheater bar to the inside cab roof since it would roll under the seat at times and shut down the machine.
-Connectivity/Age. I had to raise the cab and clean up underneath the seat since the seat wouldn't adjust anymore to include doing maintenance on the seat rails, seat springs, and most importantly the sensor (sensor is surrounded by magnet collar). I found the sensor had become corroded to the point of taking a wire wheel brush to ensure connectivity.(also the sensor harness is connected under the cab).
i. Traction Lock Stop. If/when the above doesn't pan out, I can provide details on. It includes minor chain case work and inspecting the solenoid.
Good luck 'LD, & Let us know how it turns out.
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