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Frequently Asked Questions - Pumps

Q: I have a HC-PTO-1A pump. I am only getting 900 pounds of hydraulic pressure. What do I have to go to get 2000 pounds of pressure out of it. Please let me know.

It is important to note that a gear pump generates flow. It is the other parts of the system that resist flow, and build up pressure. Therefore, it is important to look over the entire system when investigating a pressure related problem.

Some common items to check:

1) Check oil levels. Low oil levels can introduce air into the system, causing many problems, including loss of flow and/or pressure.

2) Is the hydraulic reservoir large enough for the PTO gpm output? It is important to insure the correct amount of reservoir capacity to avoid problems. A basic rule of thumb is to get at least 1 gallon of reservoir capacity per 1 GPM of pump capacity. (i.e. 21 gpm pump output = 21 gal. or larger reservoir.)

3) Is the pump functioning properly? The proper way to check a pump output is with a flow meter, not a pressure gauge. If the pump is not producing the correct flow, it may be damaged, and require replacement. (See: Common Causes of Pump Failure.)

4) Is the system Plumbed properly? Is the oil passing around, rather than through its intended path? Is the oil passing over a relief set too low?

5) Is the system working properly with the currently generated pressure? Many hydraulic systems do not use the full extent of rated pressure unless at full load. If you do not have enough load on the system, you will not generate a very high pressure.

Please refer to the PTO Parts Manual to ensure the pump is plumbed properly. You can visit PTO Pumps Page and select Parts Manual to down load or print a copy of the manual.

Common Causes of Pump Failure

Q: What are the most common things apart from pressure or speed that can cause a pump to fail?

A: The most common things that cause a pump to fail fall into three categories; Cavitation, Contamination, and Heat.

Cavitation: This is caused by a lack of oil flowing into the inlet port. It will damage the pump, and reduce flow. If you see foamy oil, it is a good indication of cavitation. Increasing the size of the inlet line or reducing flow can help with cavitation problems. Removing any elbows, bends, or filters on the inlet line can also help. Lastly, making sure that the oil reservoir is above the pump may also be beneficial.

Contamination: Contamination will not only cause damage to the pump, but may also plug valves, reliefs, etc. in the system. It is important to have the proper filtration in the system, including changing filters regularly.

Heat: Any Hydraulic system will generate heat. It is important to deal with that heat so that the oil temperature does not rise high enough to cause damage to seals, valves, etc. Having a properly sized oil reservoir (or oil cooler if necessary) is important in order to avoid excessive heat buildup in the system.

Lastly, make sure to refer to your manual for the proper pressure/speed limits. Exceeding those limits will damage a pump, and cause it to fail prematurely.