Checklist for Hydraulic Power Troubleshooting
Made of a number of precision machined components, hydraulic equipment and systems require care and maintenance to get the best of them and in order to give them what they need for long lasting and trouble-free operation.
We’ve covered troubleshooting before, and if you want to know more in further detail then check out our blog posts on:
Troubleshoot Hydraulics: Basic Knowledge
Troubleshooting Hydraulic Relief Valves
This checklist is for those who have not had extensive experience with troubleshooting hydraulics and it might suit your interns or newbies in the workshop.
Let’s get started.
First off, it’s essential to keep all of the hydraulic system clean. This includes the hydraulic fluid. Oil and oil filters need to be changed at regular intervals. You could say that dirt and grime is your and your equipment’s worst enemy and it’s your role to keep it at bay and prevent it from messing up your machinery and its peripherals.
Here is a checklist of what is at the root of most trouble:
1. The fluid or oil being used is not of the correct viscosity.
2. There is not enough fluid or oil in the system
3. There is a leak
4. There is dirt, moisture or there is another foreign body in the system
5. There is air in the system
6. Structural failure.
7. Adjustments have been made but they are wrong
Here are some shortcuts to answers that you can refer to when getting started with hydraulic troubleshooting:
Your Pump is Operating Incorrectly and not delivering fluid or oil. It could be down to any of these reasons:
· The fluid is too low in the reservoir. You may need to check its level and refill if necessary.
· If there is a hole in your intake pipe allowing air to pass through, you may hear a noise or experience erratic results. This will need to be repaired. Alternatively there could be a blockage in your filter. In which case, you will need to clean it.
· The oil is too thick and the viscosity is too heavy. Check the specs suggested by the manufacturer.
· The pump shaft is rotating in the wrong direction. Reverse it otherwise you will cause irreparable damage as there won’t be enough lubricant.
· Dirt in the pump – clean it.
Your System is Not Developing Pressure
The most likely causes for this type of situation are:
· The pump is not delivering fluid (see info above – with remedies listed)
· The relief valve is malfunctioning either through leakage, incorrect settings or because the valve spring is broken. You may need to check the settings according to the manufacturer, check the valve seat to look for either dirt or scoring or even replace the spring and then adjust it as suitable.
· The valves may be allowing the oil to be recirculated through the system. Check the directional valve to ascertain what the situation is with it.
· There is leakage internally in the valves or the cylinders. Check these components and their condition.
Pump is making noise
· The intake line or the filter is not allowing fluid to pass. Clean these and assure there are no kinks or anything to stop them being fully open.
· There are air leaks either in the intake pipe at the joints, at the pump shaft packing or through the inlet pipe opening. You can check the joints for leaks by pouring on oil. Also check the shaft by pouring oil onto it and check that the inlet pipes are below the oil level in the reservoir to ensure that suction is strong enough.
· If you are seeing air bubbles, you may need to use an oil with a foam depressant.
· Check the reservoir air vent to see if it’s plugged, if so clean it.
· You may find that the pump is running too fast, in which case you will need to refer to the manufacturer’s specifications.
· The oil is at the wrong viscosity. Again, check the manufacturer’s specifications for details.
· Check whether the filter is of the correct size, as this could also be a problem. Refer to manufacturer’s specs for details.
· Check for work or broken components and parts, and replace as necessary.
If you’re experiencing an external oil leak around the pump, you may need to look for:
· Worn shaft packing which needs replacing
· Head packing damaged, again replace it.
· Loose or broken parts, which may need to be tightened or replaced.
Excessive wear can be caused by and remedied as follows:
· Abrasive material or dirt in oil being circulated. Clean and/or replace the filter and change the oil.
· If the viscosity of the oil is too low, check what is recommended by the manufacturers.
· Pressure could be too high for maximum rating of the pump. In which case you may need to check the settings of the relief valve or regulator valve.
· The drive is not aligned correctly. Check this and correct as appropriately.
· Air is in the system. This will need to be removed.
Broken pump parts can come about from:
· Pressures are above the maximum pump rating check the relief or regulator valve settings.
· Seizure from lack of oil in the system. Check the level of the reservoir, the oil filter and the suction line.
· Dirt or material in the pump – clean it and check the filter.
· The head is screwed on too tight – check the specifications as listed by the manufacturer.
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