I have a cat skidd steer 277b sn# MDH00744 trying to figure…

B models are all about the same, serial number won't change much on the location. The fitting may be at a different angle but, still about the same location.

The actual meaning for the MDH 1 and up is, serial number MDH00001 and up.

That is possible.

Your only option now is to raise the cab and wash out the dirt under the pump until you can find the manifold or drain hose.

I have checked other manuals and found a different image that may help.

The manifold is bolted to the floor of the machine, just below the hydraulic tank. It is to the right side of the floor but, the drain port is near the center.

Follow the large hose from the bottom of the hydraulic tank and it will connect to the manifold.

The drain hose is often removed or twisted around under other lines and may be hard to see. Just pull on the hoses and squeeze them.

The drain hose is actually a heater hose and will be very soft. (No wire braiding used inside the hose.)

The images are never true to scale. Do feel bad, it is hard to see until you find it the first time.

Sorry for the late reply. I had so personal matters that kept me away.

I do not like engine oils used as hydraulic fluid. I think they all lack the true additives to protect your pumps.

You will see much more early wear on the pumps and damage to cylinder seals as none the the friction modifiers are in engine oil.

10W hydraulic oil is still the best unless you are in a very cold or very hot climate. This machine has two very expensive piston type hydraulic pumps. They are very sensitive to dirt or running out of oil. Multi-weight oils are often to thick when cold and can cause cavitation erosion.

Here is the spec' from the manual.

Hydraulic Oil

Applications

• Hydraulic Systems

   

• Hydrostatic Transmissions

   

Caterpillar has developed a new class of hydraulic oils, the HYDO Advanced fluids. These new advanced fluids are designed for optimal performance in new advanced hydraulic systems that are designed with close tolerances for precise operation and that operate under demanding conditions of temperatures and pressures. These fluids ensure optimal performance in current and previous hydraulic systems. Four new products have been introduced:

• HYDO Advanced 10, SAE 10W

   

• HYDO Advanced 20, SAE 20W

   

• HYDO Advanced 30, SAE 30

   

• Bio HYDO Advanced, Multigrade

   

Cat HYDO Advanced Hydraulic Oils, SAE 10W, SAE 20W, and SAE 30

Cat HYDO Advanced hydraulic oils are designed to provide extended oil drain intervals and to provide extra protection to Cat hydraulic system components and hydrostatic transmissions.

Cat HYDO Advanced hydraulic oils are formulated of premium additives and premium base stocks that pass severe qualification testing requirements, in the field and in the laboratory, in order to provide superior protection for Cat hydraulic systems.

Cat HYDO Advanced hydraulic oils are preferred in most hydraulic systems and in most hydrostatic systems. Refer to this Special Publication, "Lubricant Viscosities", Table "Hydraulic Systems Lubricant Viscosities for Ambient Temperatures" for the ambient operating temperatures for Cat HYDO Advanced hydraulic oils.

Cat HYDO Advanced oils allow 6000 hours or higher oil drain intervals for most applications. S·O·S Services oil analysis is recommended when the oil drain interval is increased to 6000 hours or higher. In comparison, non Cat commercial hydraulic oils (second choice oils), allow for a 2000 hour oil drain interval. Caterpillar recommends following the maintenance interval schedule for oil filter changes and for oil sampling that is stated in the Operation and Maintenance Manualfor your machine. Consult your Cat dealer for details.

Cat HYDO Advanced hydraulic oils offer the following benefits:

• Enhanced anti wear protection: protect wear surfaces and reduce component wear in various hydraulic pumps.

   

• Protection against rusting and corrosive wear.

   

• Dispersion of water prevents pump damage due to water ingestion and prevents system damage due to freezing of water.

   

• 250% increase in oxidation stability per "ASTM D943".

   

• Rapid air release protects against cavitation.

   

• Improved filtration properties helps support component cleanliness.

   

Cat HYDO Advanced hydraulic oils should be used to achieve maximum life and maximum performance from hydraulic system components and from hydrostatic transmissions. In order to gain the most benefit from the improved performance designed into Cat HYDO Advanced oils, when switching to Cat HYDO Advanced oils, cross contamination with the previous hydraulic oil should be kept to less than 10%.

If a different viscosity is required due to ambient temperatures, the following Caterpillar oils can be used:

• Cat DEO-ULS and Cat DEO

   

• Cat DEO-ULS SYN and Cat DEO SYN

   

• Cat DEO Cold Weather

   

• Cat TDTO

   

• Cat TDTO Cold Weather

   

• Cat TDTO-TMS

   

• Cat MTO

   

Note: Oil drain intervals of the oils listed above are less than the intervals of Cat HYDO Advanced oils. The oil drain intervals of the listed oils are typically 2000 hours and up to a maximum of 4000 hours. An exception is Cat TDTO Cold Weather oil, which allows for a 6000 hour oil drain interval or higher. S·O·S Services oil analysis is required when the oils listed above are used in Cat hydraulic system components and hydrostatic transmissions.

Note: Caterpillar oil availability will vary by region.

For applications requiring the use of fire resistant hydraulic fluids, Caterpillar recommends the use of EcoSafe FR-46. This product is a fully synthetic, non-aqueous hydraulic fluid. Water based and glycol based hydraulic products are not recommended for use in Cat machine hydraulic systems. EcoSafe FR-46 is an ISO 46 multi-grade product. For more information refer to the product information provided by the manufacturer of EcoSafe hydraulic oil. Refer to your Cat dealer for availability.

DEO means, Diesel Engine Oil It is ok to use but, not the first choice. Here are spec's to use for other suppliers.

Commercial Oils

Note: Non-Caterpillar commercial oils that are acceptable for use in most Cat hydraulic and hydrostatic transmission systems are as a group third choice oils. Within this grouping of third choice oils there are tiered levels of performance.

NOTICE

Cat does not warrant the quality or performance of non-Cat fluids.

The minimum viscosity for commercial alternative oils used in most Caterpillar machine hydraulic systems and in most Cat hydrostatic transmission systems is 6.6 cSt at 100 °C (212 °F) "ASTM D445".

If Caterpillar oils cannot be used, oils meeting the following commercial specifications can be used in most Cat hydraulic systems and in most Cat hydrostatic transmission systems:

• Engine oils that meet the Cat ECF-1-a, Cat ECF-2, or Cat ECF-3 specifications and have a minimum zinc additive of 0.09 percent (900 ppm)

   

• Biodegradable oils that meet the Cat BF-2 specification

   

• TO-4 specification oils that have a minimum zinc additive of 0.09 percent (900 ppm)

   

Note: Industrial hydraulic oils are not recommended for service fill in Caterpillar hydraulic systems.