How to Replace a Hydraulic Hose
Locate the problem hose., Assess how many components must be removed to facilitate replacing the damaged hose., Determine if the hydraulic component the hose serves, or any other hydraulic components which must be removed have a live load, or weight...
Step-by-Step Guide
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Step 1: Locate the problem hose.
This may be obvious if the hose has burst, since they typically handle oil at over 2000 PSI pressure, and one that bursts will discharge a large amount of oil in a short time.
If the situation is a small leak, though, you will need to observe where the oil is dripping, and follow the wet trail it leads to the source.
Never use your hands or body parts to find the leak.
Use cardboard, paper or hydraulic leak detection fluid so no oil injection is accrued.
A good hydraulic shop stocks leak detection additives that assist on location the leak safely. , Always label the component removed by number and letter so replacement of parts can be reinstalled with ease.
This may include housings, guards, clamps, other hoses, hydraulic cylinders, and more.
Follow the hose from one end to the other, noting the route you will use to uninstall and reinstall it.
Putting a number and letter on the ports and hose ends. , If the oil in the system you are disconnecting is under pressure, it may blow out forcefully when the fittings which hold it are loosened, causing oil to be discharged under pressure.
Relieve the pressure from these cylinders or components before proceeding. , The weight of an attachment can crush a mechanic if it suddenly falls when pressure is relieved in the cylinder that is supporting it. , The fittings on the each end of the hose will be removed with a wrench, which may vary in size from 9/16 to over 1 1⁄2 inches (3.8 cm).
Many of these fittings are designed to swivel or turn as they operate, so two wrenches will be required to remove each of them.
Hold the stationary side of the coupling with one wrench to prevent it from turning, and possibly damaging an O-ring while turning the other to separate the coupling. , Often, the hydraulic cylinder itself will need to be removed or supported so that fittings can be accessed.
Hydraulic cylinders are either bolted directly to the boss or fixture which it operates, or is anchored with a steel pin, such as the one in the illustration. , Make sure the fitting turns at the threaded connection, and does not twist any other part.
If needed, you may have to hold the fitting the hose is attached to with a separate wrench. , Be aware that some hydraulic oil may leak from either or both connections, and the oil that is remaining in the hose will also dump out, so having a bucket handy to catch this spillage is a good idea., If you do not have oil dripping from the fitting, and do not have a plug with the correct threads on it, you may tie a clean rag around the fitting to protect it, but be careful if rain is in the forecast, since a rag won't protect the system from being contaminated with water., After market manufacturers and OEM dealers supply replacement hoses and fittings which can be assembled while you wait, and are less expensive than ordering an original equipment manufacturer's product.
Make sure the hydraulic shop that makes the hose will clean the hoses inside with a proper cleaning system not just shop air.
A proper hydraulic hose shop like ASAP hydraulics will use an ultra clean system and install end caps to make sure no contamination will enter into the system.
The end caps will keep the line clean until the line is routed throughout the system and ready to install. , Make sure there is no dirt in the tubing or fitting which will end up in the hydraulic system when you are finished. , This will keep dirt and debris from being forced into the hose while installing it.
Remove these temporary plugs immediately before installing the fittings where they mate up with their counterparts. , Tighten these connections snugly.
You may have access to a specification book which recommends a torque to apply to each fitting, but failing this, tighten them as much as you can without risking damaging the seals or stripping the threads which hold them., Align any cylinder pins which were removed, and reinstall them, and return any split or snap rings which hold them in place. , If you have had a chance to clean all surfaces that were soiled by the initial leak, any leaks that occur now will be much easier to spot.
Keep in mind some hydraulic circuits will require bleeding to remove air from the system prior to using the machine.
This usually applied to steering and brake systems, but there are other situations where air can become trapped, such as a single action cylinder where the hydraulic supply is at a low point in the cylinder. -
Step 2: Assess how many components must be removed to facilitate replacing the damaged hose.
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Step 3: Determine if the hydraulic component the hose serves
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Step 4: or any other hydraulic components which must be removed have a live load
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Step 5: or weight on them.
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Step 6: Make sure any attachments which are supported by the hydraulic cylinder the hose operates are lowered to the ground or blocked or chained up.
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Step 7: Get the tools you will need to perform the job of removing the hose.
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Step 8: Remove all clamps and attachments which will interfere with removing the hose.
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Step 9: Loosen the fitting that attaches the hydraulic hose to the hydraulic system
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Step 10: either at a coupling
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Step 11: a cylinder
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Step 12: or the valve spool itself.
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Step 13: Pull the hose off of the equipment when both ends are unfastened.
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Step 14: Plug the fittings that remain on the machine to keep debris from getting into the system during the interval the fitting is open.
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Step 15: Wipe excess oil from the hose
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Step 16: and take it to an equipment supply store to have a new one ordered or made.
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Step 17: Clean all the fittings on the equipment before reinstalling the hose.
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Step 18: Plug the ends of your new hoses with a special cap or a clean rag before routing it through the equipment to where it goes.
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Step 19: Make sure the hose is in the correct location
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Step 20: and it has the proper amount of slack where needed when it is installed
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Step 21: then thread the fittings back on the cylinder or other component where they were removed.
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Step 22: Replace any clamps
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Step 23: guards
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Step 24: or other components which were removed to accomplish the task.
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Step 25: Check the fluid level in the machine
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Step 26: crank it up
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Step 27: and check for leaks.
Detailed Guide
This may be obvious if the hose has burst, since they typically handle oil at over 2000 PSI pressure, and one that bursts will discharge a large amount of oil in a short time.
If the situation is a small leak, though, you will need to observe where the oil is dripping, and follow the wet trail it leads to the source.
Never use your hands or body parts to find the leak.
Use cardboard, paper or hydraulic leak detection fluid so no oil injection is accrued.
A good hydraulic shop stocks leak detection additives that assist on location the leak safely. , Always label the component removed by number and letter so replacement of parts can be reinstalled with ease.
This may include housings, guards, clamps, other hoses, hydraulic cylinders, and more.
Follow the hose from one end to the other, noting the route you will use to uninstall and reinstall it.
Putting a number and letter on the ports and hose ends. , If the oil in the system you are disconnecting is under pressure, it may blow out forcefully when the fittings which hold it are loosened, causing oil to be discharged under pressure.
Relieve the pressure from these cylinders or components before proceeding. , The weight of an attachment can crush a mechanic if it suddenly falls when pressure is relieved in the cylinder that is supporting it. , The fittings on the each end of the hose will be removed with a wrench, which may vary in size from 9/16 to over 1 1⁄2 inches (3.8 cm).
Many of these fittings are designed to swivel or turn as they operate, so two wrenches will be required to remove each of them.
Hold the stationary side of the coupling with one wrench to prevent it from turning, and possibly damaging an O-ring while turning the other to separate the coupling. , Often, the hydraulic cylinder itself will need to be removed or supported so that fittings can be accessed.
Hydraulic cylinders are either bolted directly to the boss or fixture which it operates, or is anchored with a steel pin, such as the one in the illustration. , Make sure the fitting turns at the threaded connection, and does not twist any other part.
If needed, you may have to hold the fitting the hose is attached to with a separate wrench. , Be aware that some hydraulic oil may leak from either or both connections, and the oil that is remaining in the hose will also dump out, so having a bucket handy to catch this spillage is a good idea., If you do not have oil dripping from the fitting, and do not have a plug with the correct threads on it, you may tie a clean rag around the fitting to protect it, but be careful if rain is in the forecast, since a rag won't protect the system from being contaminated with water., After market manufacturers and OEM dealers supply replacement hoses and fittings which can be assembled while you wait, and are less expensive than ordering an original equipment manufacturer's product.
Make sure the hydraulic shop that makes the hose will clean the hoses inside with a proper cleaning system not just shop air.
A proper hydraulic hose shop like ASAP hydraulics will use an ultra clean system and install end caps to make sure no contamination will enter into the system.
The end caps will keep the line clean until the line is routed throughout the system and ready to install. , Make sure there is no dirt in the tubing or fitting which will end up in the hydraulic system when you are finished. , This will keep dirt and debris from being forced into the hose while installing it.
Remove these temporary plugs immediately before installing the fittings where they mate up with their counterparts. , Tighten these connections snugly.
You may have access to a specification book which recommends a torque to apply to each fitting, but failing this, tighten them as much as you can without risking damaging the seals or stripping the threads which hold them., Align any cylinder pins which were removed, and reinstall them, and return any split or snap rings which hold them in place. , If you have had a chance to clean all surfaces that were soiled by the initial leak, any leaks that occur now will be much easier to spot.
Keep in mind some hydraulic circuits will require bleeding to remove air from the system prior to using the machine.
This usually applied to steering and brake systems, but there are other situations where air can become trapped, such as a single action cylinder where the hydraulic supply is at a low point in the cylinder.
About the Author
Christine Flores
Dedicated to helping readers learn new skills in home improvement and beyond.
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