AC 4905979

Frequently Asked Questions

Q: What motors does the AC 4905979 carbon composite brush set fit?
A: The AC 4905979 is an OEM brush set designed for Allis-Chalmers electric lift truck traction motors or lift (pump) motors. The carbon composite construction is optimized for high electrical current conduction in DC motor applications.

Q: What is the difference between AC 4905979 and AC 4905973 brush sets?
A: Both are OEM Allis-Chalmers brush sets for lift truck motors. The AC 4905973 specifies 4 brushes with exact dimensions (1.3 x 1.24 x 0.628 inches). The AC 4905979 is a carbon composite brush set with similar high-current capability. Verify your motor configuration to select the correct part.

Q: What material is the AC 4905979 brush set made from?
A: The AC 4905979 uses a carbon composite material designed for electrical current conduction and durability in lift truck motor environments. Carbon composite brushes offer reliable performance across varying load and speed conditions.

Q: How does the AC 4905979 handle current transients during lift truck acceleration?
A: The carbon composite brush material is engineered to withstand current surges that occur during rapid acceleration and full-load lifting cycles. This prevents brush chatter, arcing, or premature wear in high-demand electric lift truck duty.

Q: What symptoms indicate the AC 4905979 brushes should be replaced?
A: Replace brushes when motor power is reduced, acceleration is sluggish, excessive commutator sparking is visible, or brushes are worn below minimum thickness. These conditions indicate failing electrical contact between brush and commutator.