Hydraulic Repair, Troubleshooting & Field Service
A hydraulic problem can shut down an entire machine.
When the Hydraulic System Isn't Doing Its Job, You Need More Than a Parts Changer
Sometimes the failure is obvious. A hose blew. A cylinder is leaking. A pump failed.
Other times the machine is slow, weak, running hot, losing power under load, or repeatedly damaging components, and nobody has been able to explain why.
That is where Mondak Equipment comes in.
We provide complete hydraulic repair and troubleshooting for heavy equipment, from hose and component repair to field diagnostics of the complete hydraulic system.
Our job is not to start changing parts until the problem disappears.
Our job is to figure out what failed, why it failed, and what it is going to take to get the equipment working correctly again.
Tell us what the machine is doing. We'll start there.
Hydraulic Problems Cost More Than the Failed Part
The obvious failure is not always the root problem.
A damaged pump may have been caused by contamination.
A cylinder may keep leaking because the rod is damaged or the mounting points are worn.
A hose may keep failing because of routing, heat, abrasion or movement.
A hydraulic system may run hot because oil is bypassing somewhere it should not.
Replacing the failed component can get the machine moving again.
But if the condition that caused the failure is still there, you may be repairing the same machine again sooner than you should.
Mondak looks at the component and the system around it.
Hydraulic Services
Hydraulic Hose & Fittings
A blown hose should not turn into an all-day search for the right fitting.
Mondak provides shop and mobile hydraulic hose service, custom hose assemblies, fittings and adapters for heavy equipment.
We are a BALFLEX Master Distributor and also handle Adaptall, GK Fittings, Parker and other hydraulic products.
That gives us options for equipment using:
- JIC
- ORFS
- SAE
- NPT
- BSP
- JIS
- DIN
- Metric
- Flange connections
- Other hydraulic connections
If the fitting is unusual, metric or simply something you have not seen before, bring it to us.
We would rather identify what is actually on the machine than start modifying everything because the correct connection is harder to find.
You can also shop hydraulic hose and fittings online at our store, MondakHose.com.
Hydraulic Cylinder Repair & Rebuilding
Sometimes a cylinder needs seals.
Sometimes it needs a lot more than seals.
Mondak repairs hydraulic cylinders with problems involving:
- Leaking or bypassing seals
- Bent, scored or pitted rods
- Barrel damage
- Pistons and glands
- Pins and bushings
- Worn mounting points
- Damaged threads
- Worn bores
- Related mechanical damage
Our machining, welding and fabrication capabilities give us additional options when replacement parts are expensive, obsolete or unavailable.
Hydraulic Pump, Motor & Valve Repair
Mondak works with hydraulic components found throughout mobile and industrial equipment.
That includes:
- Gear pumps
- Piston pumps
- Vane pumps
- Variable-displacement pumps
- Hydraulic motors
- Hydrostatic components
- Directional valves
- Cartridge valves
- Proportional valves
- Relief and counterbalance valves
- Manifolds and controls
We deal in and work with hydraulic products from manufacturers such as Honor Pump and Parker, along with components from many of the major hydraulic manufacturers used throughout heavy equipment.
We also regularly encounter older names such as Vickers, Sauer-Sundstrand, Char-Lynn, Commercial Intertech and others still operating in equipment every day.
The name on the component does not have to be current for us to be interested in repairing it.
Hydraulic System Diagnostics & Field Repair
This is where hydraulic repair becomes troubleshooting.
A machine may:
- Build pressure but still be weak
- Work correctly when cold and lose performance when hot
- Run excessively hot
- Move slowly
- Stall under load
- Cavitate
- Make unusual hydraulic noise
- Repeatedly damage pumps or motors
- Keep blowing hoses
- Have intermittent functions
- Show a hydraulic symptom caused by an electrical or control problem
Mondak can troubleshoot the system using the information the machine is actually giving us.
Depending on the problem, that can include:
- Pressure testing
- Flow testing
- Case-drain testing
- Temperature diagnosis
- Pump performance testing
- Load-sense troubleshooting
- Pilot pressure
- Relief and bypass testing
- Internal leakage
- Suction problems
- Hydraulic contamination
- Electronic and proportional controls
Sometimes the answer is a failed component.
Sometimes the component everybody has been blaming is doing exactly what it is supposed to do.
Learn More About Hydraulic System Diagnostics & Field Repair
Heavy Equipment Hydraulics
Mondak works on hydraulic systems across a wide range of equipment and industries.
- Oilfield Equipment
- Workover rigs, drilling equipment, iron roughnecks, power swivels, top drives, hydraulic catwalks, HPUs and related equipment.
- Construction Equipment
- Excavators, loaders, dozers, graders, compact equipment and other hydraulic machinery.
- Aerial Equipment
- Boom lifts, scissor lifts, bucket trucks and vehicle-mounted aerial devices.
- Material Handling
- Forklifts, telehandlers, cranes and other lifting equipment.
- Agriculture
- Tractors, implements and hydraulic-powered equipment.
- Industrial & Specialty Equipment
- Hydraulic machinery that does not always fit neatly into one category.
If it operates hydraulically and there is a problem with it, there is a good chance it is something we are willing to look at.
Old Equipment Is Still Equipment
Not every hydraulic machine in the field was built recently.
A lot of good equipment is still working with pumps, valves, motors and controls that have been discontinued, renamed or absorbed into another product line.
That does not automatically mean the machine needs to be replaced.
Depending on the situation, Mondak can look at options such as:
- Repairing the original component
- Cross-referencing a replacement
- Adapting a current-production component
- Machining replacement parts
- Fabricating brackets or mounts
- Repairing cylinders
- Modifying hydraulic plumbing
- Updating controls
Sometimes there is an OEM replacement.
Sometimes there is not.
Either way, we can help figure out what options make sense.
When the Same Part Keeps Failing
A repeated failure is telling you something.
If a pump has been replaced twice, another pump may not be the first thing the machine needs.
The same applies to motors, cylinders, valves and hoses.
Repeated failures can be caused by conditions such as:
- Contamination
- Excessive temperature
- Incorrect pressure settings
- Relief or bypass flow
- Suction restrictions
- Cavitation
- Aeration
- Mechanical binding
- Incorrect component application
- Poor hose routing
- Electrical or control problems
The damaged component matters.
The reason it became damaged matters too.
Hydraulic Heat & Contamination
Two of the biggest enemies of hydraulic systems are heat and contamination.
Dirty oil can damage precision hydraulic components throughout a system.
Excessive heat can reduce oil life, damage seals and increase internal leakage.
And the source is not always obvious.
A hot hydraulic system may have:
- A worn pump or motor
- Internal leakage
- A relief valve bypassing
- A cooling problem
- A restricted filter
- A suction problem
- Incorrect or degraded fluid
- Excessive load
- Aeration or cavitation
The goal is not simply to make the oil cooler.
The goal is to determine whether the system is operating the way it should, and if it is not, why.
Shop Repair When It Belongs in the Shop
Some hydraulic components need to come off the machine.
Mondak's shop capabilities allow us to handle work involving:
- Hydraulic cylinders
- Pumps
- Motors
- Valves
- Hose assemblies
- Machining
- Welding
- Fabrication
- Component repair
That allows the field technician and the shop to work together instead of treating the machine and the failed component as two unrelated problems.
Field Hydraulic Service When the Machine Needs to Stay Put
A lot of the equipment we work on is too large, too integrated or too expensive to transport every time there is a hydraulic problem.
That is why field service is an important part of what Mondak does.
We can troubleshoot the machine where it is operating, determine what the system is doing under actual conditions, and repair what makes sense in the field.
If a cylinder, pump, motor or other component needs shop work, it can be removed and handled separately.
You Don't Have to Diagnose It Before You Call
You may know exactly what failed.
If you do, tell us.
If all you know is:
- "It gets weak when it heats up."
- "The boom is slow."
- "We just put another pump on it."
- "This hose keeps blowing."
- "Nobody can figure out why it won't build power."
That is enough to start a conversation.
Give us the manufacturer, model, what the machine is doing, when it happens, and what has already been tried.
We'll take it from there.
Answers for this service
Why is a hydraulic leak sometimes more complicated than replacing a hose?
A leaking hose is sometimes only the symptom. Incorrect routing, abrasion, excessive pressure, heat, vibration, improper fitting selection or movement can cause the replacement hose to fail again.
When repeated failures occur, we look for the reason the hose is failing rather than simply installing another hose.
How does Mondak determine which hydraulic hose belongs on a machine?
Hose selection is based on working pressure, temperature, fluid compatibility, movement, routing, bend radius, fitting type and application.
We don't select hose simply because it fits physically.
What if my machine uses a fitting that isn't common in North America?
That is one of the areas where Mondak's inventory and experience can make a difference. We stock and work with multiple fitting standards, including JIC, ORFS, BSP, JIS and VOSS configurations.
International equipment often requires connections that a typical North American hose shop may not have on the shelf.
Why can't I substitute a similar-looking hydraulic fitting?
Two fittings can look almost identical while using different thread forms or sealing methods. Installing the wrong connection can cause leaks, damaged threads or an unsafe hydraulic failure.
A fitting that appears to screw together can still have the wrong thread or sealing method.
What if the hydraulic pump is suspected to be bad?
We don't automatically condemn the pump. Pressure and flow testing, control checks and system diagnosis can help determine whether the pump is actually producing the required performance.
A valve, control signal, relief circuit or mechanical problem can sometimes look like a bad pump.
How can Mondak tell if a hydraulic cylinder needs rebuilding?
The cylinder is evaluated for leakage, rod condition, scoring, wear, seal condition and other damage. The cause of the failure is also considered so the rebuilt cylinder isn't simply put back into a system that caused the original problem.
What hydraulic components does Mondak repair besides hoses?
We repair cylinders, pumps, motors, valves, solenoids, relief valves, hydraulic power units and related hydraulic components.
Can Mondak repair the machine and build the hydraulic hose at the same time?
Yes. Equipment repair and hydraulic hose work are handled within the same company.
A technician can identify a failed hose, determine why it failed, build the replacement and address the underlying equipment problem without sending the customer to another company for the hose.
Get the Equipment Working the Way It Should
You need the machine back at work, not another box of parts and the same problem. Mondak Equipment can help with the hose, the component, or the complete hydraulic system.
Tell us what you have and what it is doing. We'll start there.
Contact Mondak Equipment