Repair or Replace? When Your Old Machine Starts Eating Your Profit Cost per hour, repair bills against resale, downtime, and the honest reasons to keep running the old one
Disclosure. We sell new machines and we run a service department that fixes old ones. So whether you repair or replace equipment, we make money either way. That is the one upside of this conflict: we have no reason to push you in either direction.
Short answer: Repair when the fix costs well under the machine's current value, the failures are not coming more often, and parts are still easy to get. Replace when your cost per operating hour on the old machine is higher than on a new one, or when downtime is costing you jobs. A well-maintained, paid-off machine is often the cheapest one you will ever own, so do the math before you shop.
The old machine is not the problem. The old machine sitting in the yard waiting on a part while your crew stands around is the problem.
Most repair vs replace decisions get made at the worst possible moment. The machine just died, the mechanic just called with a number, and you are mad. This guide is the math to do before you are standing next to a puddle of hydraulic oil.
Jump to what you came for
Cost Per Operating Hour
Forget the repair bill for a second. The question is what each hour of work costs you on this machine compared to a replacement. Add up ownership cost and operating cost over a period, then divide by the hours you ran it.
What goes into ownership cost
What goes into operating cost
Fuel, fluids, filters, wear parts, tires or tracks, and repairs. Repairs are the line that grows as the machine ages. On a new machine under warranty that line is close to zero for a while. Our Kubota maintenance basics cover what routine upkeep should look like, which is the baseline you are comparing against.
A worked example with round numbers
Hypothetical. Say your old excavator is paid off and worth about $20,000 today. Over the next 1,000 hours you expect it to lose $5,000 in value, need $12,000 in repairs, and burn $15,000 in fuel and maintenance. That is $32,000 over 1,000 hours, or $32 an hour.
Now say a new machine costs $70,000 and will be worth $55,000 after 1,000 hours. That is $15,000 of depreciation. Add $4,000 in interest, $1,000 in repairs outside warranty, and $13,000 in fuel and maintenance because it burns a little less. That is $33,000, or $33 an hour.
Close to a wash. That is the point. On paper, a tired old machine is often about as cheap to run as a new one. What breaks the tie is usually downtime, which we get to below. Your real numbers will be different, so plug them in. Our guide to what hours mean on used equipment helps you guess how many good hours the old one has left.
Repair Cost vs What the Machine Is Worth
A big repair on a machine worth less than the repair is a donation.
The rule of thumb
A commonly used rule of thumb: when a single repair starts approaching a large share of the machine's current value (many owners use something like half), stop and look hard before you approve it. It is not a law. A $9,000 engine job on a machine worth $15,000 can still be the right call if everything else on it is solid. But it is the point where you should price the alternative.
To know the current value, you need an honest number, not what you paid or what you wish it were worth. Our equipment trade-in value guide explains how dealers and auctions actually price used machines.
Watch the trend, not the single bill
Parts availability on older models
Older machines can get hard to feed. Some parts go on long backorder, some move to aftermarket only, and a few just stop. Before a big repair on an older model, ask the parts counter whether the common wear items are still in stock and how long special orders take. A cheap repair you wait six weeks for is not cheap.
The Big-Ticket Repairs, One at a Time
No dollar figures here, because they swing a lot by machine size, model and how much else the mechanic finds once it is apart. Get a written estimate. Here is how each one usually breaks.
| Repair | Repair usually makes sense when | Replace usually makes sense when |
|---|---|---|
| Engine overhaul | The rest of the machine is tight and the hours are reasonable for its size | Hydraulics, undercarriage and structure are also worn out |
| Hydraulic pump | It is a one-time failure and the fluid was kept clean | Contamination took out valves and cylinders along with it |
| Undercarriage | The machine is solid otherwise, since tracks are a wear item | It is the third big repair this year on the same machine |
| Final drives | One side failed and the other checks out | Both sides are going and the machine is low value |
| DPF or emissions system | Cleaning or a sensor fixes it and the cause is understood | It keeps coming back on a machine with other problems |
| Transmission or HST | The machine has a lot of life left elsewhere | The repair approaches a big share of the machine's value |
Ask what caused it
A failed part is a symptom. A pump that died because of dirty fluid will kill the next pump too. A DPF that keeps plugging usually points to how the machine is run, which our DPF regeneration guide explains. If nobody can tell you why it failed, the repair is a guess.
Check the warranty first
On a newer machine, read what Kubota's coverage actually includes before you pay anyone. Our Kubota warranty guide covers what is covered and what voids it.
Downtime Is the Real Bill
The shop invoice is the number you see. Downtime is the number you feel. For a contractor, it is usually bigger.
Lost billable days
If the machine earns money every day it works, every day it sits is money gone. Add the crew you still pay and the contractor who calls someone else next time. On a tight schedule in LA County or San Diego County, one missed week can cost more than the repair.
Rental while it is in the shop
The honest fix for downtime is often a rental. Price it into the repair decision: a two-week repair plus two weeks of rental is the real cost. Our breakdown of equipment rental rates by day, week and month shows how to keep that number down, and the rentals catalog shows what is available.
Emissions, Safety and Productivity
Emissions and Tier 4
Current diesel machines are built to Tier 4 Final emissions standards, which brought DPFs and more electronics. That means cleaner exhaust and more sensors to go wrong. In California, fleets that run older off-road diesels can also fall under state rules from CARB that affect how long certain engines can stay in use. The rules depend on fleet size, horsepower and engine tier, so check your own status with CARB or your compliance person before you spend big money on an old engine. We are not going to guess at your fleet's requirements.
Safety
Newer machines generally bring better cab protection, cameras, and other safety features. If your old machine has a cracked ROPS, missing guards, or brakes you work around, that is not a repair vs replace question. Fix it or park it.
Productivity
A newer machine may dig, lift or travel a bit faster, and burn a bit less fuel doing it. On a machine running full days, small gains add up. On a machine that works three weekends a year, they add up to nothing. Be honest about which one you have.
Taxes, Financing and Paying Cash
Section 179
A new or used machine bought for business use may qualify for Section 179 expensing, which can change the after-tax cost of replacing. Our Section 179 equipment deduction guide covers the basics. Repairs on a machine you already own are often treated as ordinary business expenses. How either one plays out for you depends on your situation, so talk to your tax advisor before you let a deduction make the decision.
Financing the replacement vs paying cash for the repair
Paying cash for a repair keeps you debt free and keeps a known machine in service. Financing a replacement spreads the cost and can protect your cash for slow months. What matters is whether the monthly payment is covered by work the machine will actually do. Our guide to Kubota financing explains how promotional rates and lease options work, and when they are not the deal they look like.
The Third Option Most People Skip
Repair now, plan replacement
Fix it, run it through the busy season, and set a date to replace it on your terms. You avoid buying in a panic, you get time to shop, and you trade in a machine that runs instead of one on a trailer with a blown pump. A running machine is worth more to every buyer. Before you trade, read our guide to inspecting used construction equipment, since the buyer will be doing exactly that to yours.
Rent to cover the gap
If you only need a second machine for a few months, or you are not sure the work will last, rent. Hillside jobs, tight backyard access, a big grading job in the Inland Empire: rent the right machine for the job and keep the old one for everyday work. Our service department can fix the old one while the rental keeps the job moving.
A well-maintained old machine that is paid off is often the cheapest machine you will ever own. We say that knowing we would rather sell you a new one.
The Short Version
Compare cost per hour
Ownership plus operating cost, divided by hours. Run it for both machines before you decide anything.
Big repair, low value, slow down
When one repair approaches a large share of what the machine is worth, price the alternative first.
Downtime breaks the tie
Lost days and rental costs usually matter more than the repair bill itself.
Paid off and healthy wins
If it runs, parts are easy and failures are rare, keep it and keep the cash.
Seven Questions Before You Sign Either Check
- What is my cost per operating hour on this machine, and what would it be on a replacement?
- What is the machine honestly worth today, and how big is this repair next to that?
- Are failures getting more frequent, and what is likely to fail next?
- Are parts for this model still in stock, and how long do special orders take?
- How many working days will I lose, and what will a rental cost to cover them?
- Do emissions rules, safety issues or warranty coverage change the answer?
- Have I talked to my tax advisor about the repair and the replacement?
Straight Answers
When should you replace heavy equipment instead of repairing it?
Replace when the cost per operating hour of the old machine is higher than a new one, when failures are getting more frequent, when parts are hard to get, or when downtime is costing you jobs. If none of that is true, repairing is usually cheaper.
What is the 50 percent rule for equipment repair?
It is a common rule of thumb, not a law. When a single repair approaches about half of the machine's current value, many owners stop and compare the cost of replacing before approving the work. Plenty of repairs above that line still make sense on an otherwise solid machine.
How do you calculate equipment cost per hour?
Add ownership costs such as depreciation, interest and insurance to operating costs such as fuel, maintenance and repairs over a period, then divide by the hours the machine ran in that period. Do the same for a replacement and compare.
Is it worth rebuilding an excavator engine?
Often yes, if the rest of the machine is in good shape and the hydraulics and undercarriage have life left. If several major systems are worn out at the same time, the rebuild money is usually better spent toward a replacement.
Should I rent while my machine is being repaired?
If the machine earns money every day it works, renting a replacement during the repair usually costs less than the lost work. Count the rental as part of the real cost of the repair.
Can I use Section 179 when replacing equipment?
New and used equipment bought for business use may qualify for Section 179 expensing, subject to limits and your tax situation. Talk to your tax advisor before you count on it.
We Get Paid Either Way, and That Is an Ad
A dealer with a shop just wrote you two thousand words on whether to buy a machine or fix one. You can see how we would come out fine on both. At least we told you up front.
Send us the repair estimate, the hour meter reading and what the machine does for you. We will run the numbers with you, and if the answer is fix the old one, our shop will be happy to take that work too.
Three generations in, the customers who stuck around were the ones we told to keep their old machine a few more years.
Request a Quote or More Info
No spam. No bots. Just real people who know equipment.