We analyzed 6,220 forklift repair service calls to answer the question:
What are the most common forklift issues in 2019?
Then we dug a little deeper to determine what it took to fix them.
And in this post, we’re going to share what we discovered.
Let’s dive in.
Contents: Top Complaints
A Summary of the Top Complaints
1. At 20.4% of all work orders surveyed, the biggest category of reported issues was leaks. The most common culprits were blown hoses and damaged tubing, which accounted for 37.59% of all reported leaks.
2. Travel and lift issues came in second among surveyed work orders, at 15.18% of complaints. Broken or corroded wiring accounted for 17.29% of root causes, the largest among all causes.
3. Accessory (horn, travel alarm and lights) issues came in third place with 13.89% of work orders. In the majority of cases (32.11%), cleaning or replacing parts solved the problem.
4. In fourth place were starting issues, at 12.89% of our survey sample. We found that 18.6% of the time, the cause was a dead battery.
5. General battery complaints made up the next most frequent complaint, with 10.53% of the total work orders surveyed. Most of the time (43.08%), replacing or charging the battery or batteries solved the problem.
6. The next most common complaint (7.49%) was that the unit was running rough. Cleaning or making adjustments to the fuel system resolved the issue in 50% of the cases.
7. Error codes and check engine lights came in next, with 6.21% of surveyed issues. Faulty electrical components were most often the culprit with 21.57% occurrence.
8. Electrical issues, including problems with buttons, switches, and pedals were next, with 5.14%. Faulty switch assemblies were the most common root cause at 28% of issues.
9. Seat and seat belt issues were eighth, with 4.26% of complaints. In 72.5% of cases, the entire assembly (seat belt, seat or cushion) needed to be replaced to fix the reported issue.
10. The smallest number of issues in our survey concerned the cooling system, with 4% of the sample. In the majority of cases (31.58%), replacing or cleaning the radiator solved the problem.
Keep reading for more detailed information from our findings.
Our Findings
Forklifts have several fluid systems, including the hydraulic, cooling, and steering systems.
Unfortunately, components in these systems like hoses and o-rings start to wear down over time. And when that happens, leaks occur.
Overall, we counted 1,269 leak-related issues in all of 2019, accounting for 20.4% of all work orders surveyed.

Most Common Causes of Leaks

Less Common Causes of Leaks
Bad engine seal
Bad control valve seal
Bad planetary gear seal
Loose oil filter
Average Costs Across All Leak Repairs

What About Safety?
Every leak issue listed here is a potential safety issue for operations that have a zero-tolerance policy for fluids on the floor.
But even if no such policy exists, fluid accumulation can put employees in danger of slipping and injuring themselves.
What Can You Do to Prevent Leaks?
Check Hoses for Wear
Since most issues involved blown hoses, a regular maintenance program can help identify those hoses that are worn and at greatest risk of failing.

Check for Loose Fittings and Clamps
Loose fittings and hoses can also be caught in this process and corrected before they become a problem.
Check for Seeping
Other issues, like leaky o-rings and cylinder seals, are more difficult to predict. They tend to wear over time, and so timing failure is a bit of a guessing game.
That being said, a watchful eye can alert you to when a fitting or o-ring is beginning to weep.
A leak is when fluid hits the ground. But a weep is when fluid begins to seep out without hitting the ground. And if caught, the weeping part can be replaced before turning into a leak.
A forklift mast that won’t go up or a lift that won't stay running present problems for operators and management alike.
Not only does it cost money in terms of lost productivity, but it also means an extra repair bill.
Overall, we counted 944 travel and lift-related issues in 2019, making up 15.18% of all work orders surveyed.

Most Common Causes of Travel and Lift Problems

Less Common Causes of Travel and Lift Problems
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Debris in the hydraulic pump
-
Check valve blockage
-
Locked up brake
-
Weak battery
-
Bad motor

Average Costs Across All Travel and Lift Repairs

What About Safety?
Though coming in fifth place with only 3.76% occurrence, fuel system issues involving the regulator are most worrisome.
A leaking regulator can cause higher levels of emissions. And that can endanger those who work in the same space.
What Can You Do to Prevent Travel and Lift Issues?
Tape Exposed Wires
While broken wires and faulty switches were the cause of some travel and lift problems with internal combustion forklifts, they were mostly found in electric forklifts. Malfunctioning contactors, on the other hand, were exclusive to electric trucks.
Unfortunately, these issues tend to reveal themselves without warning.
But, there are a couple of things that can help lessen the likelihood of failure.

Adding electrical tape or proper insulating material (if in the case of battery wires) to an exposed wire is one step. And keeping the movement of components to a minimum is another.
Keep Batteries Watered and Charged
Battery issues, however, can be prevented by performing proper maintenance. Keep them watered, charged, and out of use until completely charged.
Adjust the Fuel System and Remove Gunk
Fuel system issues, though a less frequent cause of movement issues, can be prevented with regular maintenance.
That maintenance should include cleaning the fuel system and making sure it's properly adjusted. Also, make sure to drain the regulator periodically. That can help clear it of built-up gunk, thus preventing issues in the first place.
Additionally, make sure that the steering, drive, and motor pump brushes are regularly being checked. Cleaning or replacing worn or dirty motor brushes can save you a lot of trouble down the road.
Whether for safety or operational purposes, or both, most forklifts these days have a combination of horns, travel alarms, and lights.
But as with anything, the more “things” you’ve got on your forklift, the more things can suddenly stop working.
Overall, we counted 864 accessory-related issues in 2019, making up 13.89% of all work orders surveyed.

Most Common Causes of Accessory Problems

Less Common Causes of Accessory Problems
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Missing mounting hardware
-
Blown fuse
-
Malfunctioning or misaligned switch

Average Costs Across All Accessory Repairs

What About Safety?
Since OSHA requires forklifts to have a working horn, it’s imperative that any horn issues be resolved immediately.
As far as headlights, tail lights and travel alarms are concerned, the application determines if they’re required.
For example, if the forklift is operating in low light areas, headlights will need to be fully functional.
What Can You Do to Prevent Accessory Issues?
Clean Horn Contacts and Pins
Horn contacts and pins can be cleaned at regular maintenance intervals. And greasing them with di-electric grease can help reduce metal-on-metal wear too.
But over time, these parts will degrade under repeated use until they make the horn inoperable.
The time to change the horn is before it wears out completely. Because OSHA will shut a forklift down for not having a properly-functioning horn:
"If the industrial truck is equipped with a horn as its warning device, then OSHA would consider the truck as being unsafe if the sound level of the horn has deteriorated to a level that can no longer be heard above the ambient noise in the workplace."
- OSHA
Operator Training to Reduce Damage
A common root cause of light and travel alarm problems was operator-inflicted damage.

Since they are outside the overhead guard of the machine, the assemblies themselves are prone to be hit. Operator training can help to minimize these impact-related issues.
Broken Wires & Burnt-Out Bulbs
For issues like burnt-out bulbs and broken wires, prevention is more difficult. These things happen when they happen.
Just like with your personal vehicle, sometimes forklifts just won’t start.
And also like in personal circumstances, most of the time a dead battery is the culprit.
But besides for dead batteries, we found a few other issues behind a dead forklift.
Overall, we counted 802 no start-related issues in 2019, making up 12.89% of all work orders surveyed.

Most Common Causes of No Start Problems

Less Common Causes of No Start Problems
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Bad gear selector
-
Blown fuse
-
Tracker system fault
-
Bad seat belt/seat belt switch
-
No fuel

Average Costs Across All No Start Repairs

What About Safety?
As mentioned, any fuel system leaks need to be addressed immediately, as they present an emissions concern.
And though less commonly found as a cause, seat belt issues are a major safety concern. Any belts that are ripped, torn, or frayed must be replaced before the lift can be used.
What Can You Do to Prevent No Start Issues?
Install a Battery Disconnect Switch
Unfortunately, starter batteries tend to gradually lose their power over time. Thus, they tend to give little warning when they’re about to go completely dead.
That being said, a battery disconnect switch can help prevent dead batteries at least some of the time.
Many operations have a multitude of accessories to power, including headlights, safety lights (blues, reds, and strobes), operator fans, heater/coolers, computers/VMUs, etc.
So, installing a disconnect switch can help prevent these accessories from draining the battery after the unit is powered down.
Clean the Fuel System
Fuel system issues often can be prevented with regular maintenance and cleaning.
Bad Starters & Broken Wires
Issues like bad starters and broken wires are harder to prevent. They usually don’t give much of a warning before failing.
Electric lifts use batteries as their main power source. Internal combustion trucks, on the other hand, use them to power their starter motor.
Either way, batteries play a role in the operation of just about every piece of heavy equipment out there.
And overall, we counted 655 battery-related issues in 2019, making up 10.53% of all work orders surveyed.

Most Common Causes of Battery Problems

Less Common Causes of Battery Problems
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Bad water filling system
-
Lifting eyes bent on the battery case
-
Battery leaking

Average Costs Across All Battery Repairs

What About Safety?
None of the issues listed above directly impact safety.
But since batteries are filled with acid, any leaks should be cleaned up immediately. Coating spills with baking soda will neutralize the acid and help prevent chemical injuries.
What Can You Do to Prevent Battery Issues?
Battery Maintenance
For starter batteries used in internal combustion forklifts, there’s not much you can do to prevent a dead battery issue.
Since these batteries are designed to discharge completely until they’re no good, your first sign of trouble is usually when it doesn’t start.
But for electric trucks, prevention comes down to two words: Battery maintenance.
Keep your batteries full of water. And wait until they’re fully charged before using them.
Do these two things and you can help extend the life of your battery.
Spitting and sputtering, backfiring, and losing power: these are all issues that we classified as "running rough."
The majority of work orders that we surveyed with this issue were for internal combustion trucks. But it was an ailment for some electrics as well (mainly the "losing power" issue).
Overall, we counted 466 rough running-related issues in 2019, making up 7.49% of all work orders surveyed.

Most Common Causes of Rough Running Problems

Less Common Causes of Rough Running Problems
Regulator vacuum hoses coming off or leaking
Bad alternator belt
Bad wiring harness & engine control unit (ECU)
Improperly-installed fuel line
Average Costs Across All Rough Running Repairs

What About Safety?
Leaking regulators and loose vacuum hoses from the regulator are safety concerns for the same reason as mentioned before: emissions.
What Can You Do to Prevent Rough Running Issues?
Clean and Replace
Fuel systems tend to accumulate a lot of grit and grime during normal operation.
Therefore, regularly cleaning the throttle body and regulator, as well as replacing the fuel filter will help prevent rough running issues.

Water and Charge
And given that battery issues were the second most common root cause, make sure to follow our advice from the last section: Keep them regularly watered and fully charged before using.
Limit Movement and Heat
As far as wires are concerned, the same advice from before applies here. Namely, wrap exposed wires with electrical tape. And try to limit movement and heat as best you can.
Just as in your personal vehicle, the dreaded check engine light is a problem for forklifts too.
Sometimes its presence follows the machine ceasing to operate. Other times it's a nagging issue that doesn't seem to present any symptoms along with it.
Overall, we counted 386 error code-related issues in 2019, making up 6.21% of all work orders surveyed.

Most Common Causes of Error Codes & Check Engine Lights

Less Common Causes of Error Codes & Check Engine Lights
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Bad motor
-
Faulty control handle
-
Dirty motor brushes

Average Costs Across All Error Code & Check Engine Light Repairs

What About Safety?
Unless the code directly concerns a safety feature on the lift, error codes and check engine lights are usually more of an annoyance than a safety issue.
What Can You Do to Prevent Error Codes?
Remove Debris, Keep Cool, and Limit Movement
Like some of the other issues we’ve documented, check engine lights and error codes are hard to predict.
Problems with sensors, contactors, and switches, along with broken wires, tend to happen unexpectedly.
That said, doing the best you can to limit heat, debris, and movement can help to keep these components from malfunctioning.
Water and Charge
We know we sound like a broken record on this...
But it’s important enough to keep repeating: Make sure your batteries are properly watered, charged, and not put into use until completely charged.
Clean and Record
Keeping the fuel system clean - a common cause of several issues on this list - will help prevent the mystery error code from popping up on the display.
But if/when you do get one, keep a record of it. If you see 3 or 4 of the same code in a row, that’s a good indication that a switch is going bad.
We classified most issues that fell within the broad category of "electrical" here.
That includes buttons, switches, wiring and anything else that was not specific to another particular issue and didn't directly affect the operation of the unit.
Overall, we counted 320 electrical issues in 2019, making up 5.14% of all work orders surveyed.

Most Common Causes of Electrical Problems

Less Common Causes of Electrical Problems
-
Debris
-
Bad spring
-
Blown fuses

Average Costs Across All Electrical Repairs

What About Safety?
If the electrical problem directly affects the operation of the unit, that could present a safety problem.
For example, consider a bad belly button switch on an electric pallet jack.
Because it’s designed to stop the unit from rolling back and hitting the operator, it would need to be replaced before using the unit.
What Can You Do to Prevent Electrical Issues?
Limit Heat, Moisture & Debris
As we’ve mentioned, electrical issues are by nature difficult to predict.

That being said, we did notice that some issues were caused by debris compromising sensitive equipment. So, frequently blowing out the unit can help to minimize some problems.
And keeping components clean, dry, and stationary, as well as covering any exposed wires can go a long way toward preventing electrical issues.
While not all forklifts have seats and seat belts, those that do must have them in proper working order.
Overall, we counted 265 seat and seat belt-related issues in 2019, making up 4.26% of all work orders surveyed.

Most Common Causes of Seat & Seat Belt Problems

Less Common Causes of Seat & Seat Belt Problems
We didn't find any other root causes of seat or seat belt problems in our survey sample.
Average Costs Across All Seat & Seat Belt Repairs

What About Safety?
Seats and seat belts are the last lines of defense against operator injury in the event of a collision or tip over.
Therefore, seats must be securely bolted down. And seat belts must be free of rips, tears, or fraying.

Additionally, if the truck came with a seat switch or interlocking seat belt, they must be operable. Otherwise, the lift should be removed from service until they can be fixed.
What Can You Do to Prevent Seat & Seat Belt Issues?
No Sharp Objects
Seats and seat belts are considered wearable parts.
Repeatedly getting on and off the seat and buckling and unbuckling the seat belt will cause them to degrade over time.
Nevertheless, some things can help reduce that wear.

Ensuring that operators don't have sharp objects, like keys or tools on their belt or person can help prevent seat tears.
Also, not placing objects that have sharp edges or protrusions on the seat while working can help too.
A general rule of forklifts is that the cooler you can keep the lift, the longer it will last.
Heat is the enemy of many forklift parts, especially the most critical (and expensive) ones, like the engine and transmission.
So, that’s why you should address cooling system issues as soon as they crop up.
Overall, we counted 249 cooling system-related issues in 2019, making up 4% of all work orders surveyed.

Most Common Causes of Cooling System Problems

Less Common Causes of Cooling System Problems
Fuel mixture out of adjustment
Bad regulator hose
Loose hose clamps
Cracked engine block
Average Costs Across All Cooling System Repairs

What About Safety?
None of the issues that we found directly affect safety.
What Can You Do to Prevent Cooling System Issues?
Clean with Air
In operations that handle material that produces debris, like paper mills and insulation manufacturers, radiators can become clogged quickly.

Blowing out the radiator with air at least once per shift can help to reduce overheating issues.
Other parts, like thermostats and water pumps, do degrade over time as they get hot. As a result, they are more difficult to catch before failure.
Conclusion
For those of you interested, here’s a link to our study methods.
Now it’s your turn:
What’s your #1 takeaway from this study?
Or maybe you have a question about the results?
Either way, we’d like to hear from you. So leave a comment below right now.
This was a great project providing awesome detail on fork truck repairs. This was a huge project, great effort & results.
Thank you for sharing!
Thanks for the kind comment Mark. I’m glad you enjoyed the content and the insight it provided!
Thank for sharing good knowledge and information its very helpful and understanding. Good work!
Glad you found our large study helpful and insightful!
This is a very informative blog, thanks for sharing about common forklift repairs. It will help a lot; these types of content should get appreciated. I hope to read more such informative contents in future.
Thanks for the kind words. It was an exhausting study but one that came together nicely. Keep checking back for more in-depth, informative content!
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You’re very welcome Brad. I’m glad to hear you found it useful!