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Introduction to the Bobcat M970
The Bobcat M970, often nicknamed the “Big Bob,” was one of the largest skid steer loaders produced in the early 1970s. With its robust frame, chain-driven wheels, and powerful hydraulic system, it was designed for demanding tasks in construction, agriculture, and industrial settings. Despite its age, many units remain operational today, often in rural or legacy fleets. However, due to limited documentation and evolving design standards, basic maintenance tasks—like checking and adding hydraulic fluid—can be surprisingly elusive.
Locating the Hydraulic Fluid Fill Point
Unlike modern skid steers with clearly labeled reservoirs and dipsticks, the M970’s hydraulic system is more concealed. Based on field experience and legacy knowledge:
A new owner in the Midwest purchased a 1974 Bobcat M970 at a farm auction. The machine ran well, but he couldn’t locate the hydraulic fluid check point. After consulting with a retired mechanic, he learned that the fill port was under the cab. With no hydraulic assist functioning, he used a come-along anchored to a barn beam to tilt the cab forward. Once opened, he found the reservoir cap and topped off the fluid—restoring smooth operation to the lift arms and bucket.
Safety Tips for Cab Tilting
For the Bobcat M970, use a high-quality hydraulic fluid with the following characteristics:
The 1974 Bobcat M970 remains a testament to rugged engineering. While its hydraulic system may not follow modern conventions, understanding its quirks allows operators to maintain performance and safety. Whether you're restoring one for personal use or keeping a legacy fleet alive, knowing where and how to check hydraulic fluid is essential. With a bit of ingenuity—and perhaps a come-along—you can keep this vintage skid steer running strong for years to come.
The Bobcat M970, often nicknamed the “Big Bob,” was one of the largest skid steer loaders produced in the early 1970s. With its robust frame, chain-driven wheels, and powerful hydraulic system, it was designed for demanding tasks in construction, agriculture, and industrial settings. Despite its age, many units remain operational today, often in rural or legacy fleets. However, due to limited documentation and evolving design standards, basic maintenance tasks—like checking and adding hydraulic fluid—can be surprisingly elusive.
Locating the Hydraulic Fluid Fill Point
Unlike modern skid steers with clearly labeled reservoirs and dipsticks, the M970’s hydraulic system is more concealed. Based on field experience and legacy knowledge:
- Hydraulic Fill Location: The hydraulic fluid fill port is typically located beneath the operator cab.
- Cab Access: The cab was originally designed with hydraulic assist cylinders to tilt forward for maintenance. However, many units no longer have functioning assist mechanisms.
- Manual Cab Tilting: Operators often resort to using ratchet straps, come-alongs, or chain hoists to tilt the cab safely. Extreme caution is advised, as the cab can shift suddenly if not properly secured.
- Come-Along: A hand-operated winch with a ratcheting mechanism used to pull or lift heavy objects.
- Hydraulic Assist Cylinder: A piston-driven device that helps lift or support heavy components like the operator cab.
- Chain Case: A separate compartment housing the drive chains, often mistaken for the hydraulic reservoir due to similar plug locations.
- Side Plugs Are Not Hydraulic Ports: The plugs on the sides of the M970 are for checking and adding lubricant to the chain cases, not hydraulic fluid.
- Pump Splitter Gearcase: Located between the engine and hydraulic pumps, this gearcase contains gear oil and should not be confused with the hydraulic reservoir.
A new owner in the Midwest purchased a 1974 Bobcat M970 at a farm auction. The machine ran well, but he couldn’t locate the hydraulic fluid check point. After consulting with a retired mechanic, he learned that the fill port was under the cab. With no hydraulic assist functioning, he used a come-along anchored to a barn beam to tilt the cab forward. Once opened, he found the reservoir cap and topped off the fluid—restoring smooth operation to the lift arms and bucket.
Safety Tips for Cab Tilting
- Secure the Cab: Always use redundant supports—such as jack stands or blocks—once the cab is tilted.
- Inspect for Hydraulic Cylinders: Some units may still have functioning tilt cylinders. If present, test them before resorting to manual lifting.
- Avoid Over-Tilting: If the cab tilts past its center of gravity without a stop mechanism, it can fall forward violently.
For the Bobcat M970, use a high-quality hydraulic fluid with the following characteristics:
- Viscosity: ISO 46 or ISO 68, depending on ambient temperature
- Additives: Anti-wear, anti-foam, and rust inhibitors
- Compatibility: Ensure the fluid is compatible with older seals and pump materials
- Check Fluid Monthly: Older machines may leak or consume fluid more rapidly.
- Inspect Hoses and Fittings: Look for cracks, bulges, or seepage around connections.
- Flush System Periodically: Every 1–2 years, consider draining and replacing the fluid to remove contaminants.
The 1974 Bobcat M970 remains a testament to rugged engineering. While its hydraulic system may not follow modern conventions, understanding its quirks allows operators to maintain performance and safety. Whether you're restoring one for personal use or keeping a legacy fleet alive, knowing where and how to check hydraulic fluid is essential. With a bit of ingenuity—and perhaps a come-along—you can keep this vintage skid steer running strong for years to come.
