Product Description
OEM master cylinder 91246-45300 is designed as a direct replacement for hydraulic brake systems in Caterpillar and Mitsubishi electric lift trucks. Key features include cast aluminum construction, steel piston, and internal return spring. The assembly converts mechanical pedal input to hydraulic pressure for service brake actuation. No cross-reference part numbers beyond 91246-15300 are confirmed; detailed port and bore dimensions require direct verification from the installed component.
Specifications
Hydraulic/Pneumatic
| Hydraulic Function | Converts mechanical input force to hydraulic pressure for brake actuation |
Material & Construction
| Body Material | Cast aluminum housing with precision-machined bore |
| Seal Materials | Brake fluid compatible synthetic elastomer seals; kit available under OEM service part |
Part Numbers
| OEM Part Number | 91246-45300 |
| Equivalent Part Numbers | 91246-15300 (noted for related Mitsubishi brake master cylinders; verify compatibility before interchange) |
Frequently Asked Questions
Q: What is the construction material of the 91246-45300 master cylinder?
A: The 91246-45300 features a cast aluminum housing with a precision-machined bore and steel piston. The aluminum construction reduces weight compared to cast iron designs while maintaining durability and heat dissipation in hydraulic brake applications.
Q: Which lift truck brands and models use the 91246-45300?
A: The 91246-45300 is a direct replacement for Caterpillar and Mitsubishi electric lift trucks. Verify your specific equipment model number and serial range against the OEM compatibility list before ordering. Brake system specifications vary by manufacturer and equipment capacity.
Q: Is there a cross-reference part number for the 91246-45300?
A: The 91246-15300 is noted as a related part number for certain Mitsubishi brake master cylinders. However, do not assume automatic interchangeability. Verify bore diameter, port configuration, and mounting flange compatibility before substituting one for the other.
Q: How does the 91246-45300 convert mechanical input to hydraulic pressure?
A: The master cylinder contains a steel piston driven by the brake pedal linkage. As the piston moves forward, it compresses brake fluid in the sealed bore, creating hydraulic pressure. An internal return spring resets the piston when pedal pressure is released, returning the system to neutral.
Q: What maintenance does the 91246-45300 require?
A: Check brake fluid level regularly and maintain the specified DOT fluid type. Inspect for external leakage around the piston rod seal and the port connections. If fluid loss, spongy pedal feel, or pressure loss occurs, the unit should be tested and replaced if internal seal wear is confirmed.