Pressure Test Radiator Cap Cost Estimate

Worried you might overpay for your radiator cap pressure test? Use Jerry's GarageGuard™ to get fair cost estimate for your radiator cap pressure test.
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John Davis
Expert Automotive Writer
Reviewed by Kathleen Flear, Director of Content
Edited by Jessica Barrett, Senior Car & Insurance Editor

How much does it cost to pressure-test a radiator cap?

While the exact price will vary based on your location and vehicle, the average cost for a radiator cap pressure test is $35. Unless repairs are necessary, you won’t need any replacement parts for the test—so all you’ll pay for is the mechanic’s labor. 
How long does it take to pressure-test a radiator cap? A trained technician should complete the service in 15 to 30 minutes. That said, most repair shops charge by the half-hour—so even if your mechanic finishes in 15 minutes, you should expect to pay for at least a half hour of labor. 

How did we estimate these prices?

Jerry's experts researched and collected data from 2500+ real repair shops in all 50 states in the US, including everything from the total cost of repair services to the hourly labor cost for mechanic labor in each shop. We combined that data with our expert database of hundreds of real repair jobs, thousands of real cars, millions of real car part prices in order to best estimate the cost of each repair service. Our labor cost estimate is calculated by taking the average hourly labor rate for a certified mechanic in the US, times the number of hours it takes on average to complete a repair. We recommend you compare your local shops with Jerry and contact those shops directly to get final pricing for your vehicle.

What parts do I need for my radiator cap pressure test?

A radiator cap pressure test isn’t a repair service but a diagnostic analysis of your car’s
cooling system
. As such, replacement parts aren’t necessary unless the mechanic finds a problem that requires repairs. 
You’ll need a few tools to perform the test. If you visit a mechanic for the service, you won’t have to worry about the tools. But if you want to pressure-test your radiator cap at home, here’s what you should have:
  • Radiator pressure tester kit: This is the primary tool you need to pressure test radiator caps and automotive cooling systems. Cooling system pressure testers include various adapters and a pump. These kits are available for $50 to $200.
  • Coolant antifreeze refractometer: This is an optional piece of equipment that measures the concentration of coolant and water mixture in the cooling system. It helps ensure that the system is optimized for cooling. Basic refractometers start around $20 to $30. 
Some reputable brands we recommend for reliable radiator pressure tester kits are Stant, OTC (OTC Tools), and Lisle. Meanwhile, the best coolant antifreeze refractometer brands include ATD Tools, AURELIO TECH, and ToolGuards. You can typically find these brands from retailers such as Amazon, AutoZone, and Harbor Freight, both online and in-store. However, like price, recommended brands may also vary depending on your vehicle's specific year, make, and model.
A basic cooling system pressure test requires no replacement parts. That means you don’t have to worry about original equipment manufacturer (OEM) vs. aftermarket parts—unless your mechanic finds a problem that requires repairs. In that case, you should opt for OEM parts whenever possible. 
OEM parts are designed specifically for your vehicle. They come with a manufacturer’s warranty and tend to be high quality. Aftermarket parts are lower quality but come with a cheaper price tag.
You can find the tools necessary for your radiator cap pressure test at your local auto parts stores and tool retailers—like AutoZone and Harbor Freight—or online retailers like Amazon. 
But what if your radiator cap pressure test reveals a problem with the engine cooling system that requires replacement parts? In that case, you can find OEM parts at your local dealership or authorized parts retailer, while aftermarket parts are available at your local parts stores and online retailers like RockAuto.

Where can I get a radiator cap pressure test?

If you don’t have a go-to mechanic, it can be difficult to find a quality auto repair shop. Fortunately, Jerry's
lets you compare repair estimates and hourly rates from more than 2,500 U.S. shops.
Jerry's GarageGuard™ uses real hourly rates from local shops to provide you with fair price estimates for common services. Use it to plan for upcoming maintenance, discover diagnostic fees, and find repair shops in your area with the best customer reviews.
Check out some of our vetted shops below and download the app to find quality mechanics in your area. 
156 Reviews
Otwell's Auto and Tire Care
7304 Indiana Ave # 1, Riverside, CA
Shop Diagnostic Fee
(Included in service charges)
124 Reviews
Noble Wholesale Tires & Auto Repair
1755 Gulf to Bay Blvd, Clearwater, FL
Shop Diagnostic Fee
(Included in service charges)
174 Reviews
Yoo's Auto Service & Collision
189 W Duncannon Ave, Philadelphia, PA
Shop Diagnostic Fee
(Included in service charges)
180 Reviews
Salazar Repair and Towing
1719 Grant St Unit #1, San Jose, CA
Shop Diagnostic Fee
(Included in service charges)

How did we vet these shops?

Jerry experts researched 2500+ real repair shops across the US. We talked to real shop customers, and analyzed both real shop pricing data and thousands of real customer reviews from each shop to verify them individually. We do not partner with the shops listed above, and our analysis is always unbiased.

How will a mechanic pressure test my radiator cap?

These are the steps a mechanic will follow to pressure-test your radiator cap:
  • Allow the car to cool down completely
  • Remove the radiator pressure cap
  • Attach the cap to the radiator pressure test kit
  • Identify the max pressure specification for the cap (it should be written on the top of the cap)
  • Using the cap test kit’s air pump, apply pressure to the cap until the pressure gauge shows the max reading written on the cap’s top
  • Observe the gauge for five minutes
  • It’s normal for the pressure to drop slowly, but if it falls rapidly, the cap is bad
  • If the old cap fails the pressure test, replace it with a new one
  • If the cap passes the pressure test, reattach it to the radiator

What happens if I don’t pressure-test my radiator cap?

If you see the warning signs of a bad radiator cap and neglect a pressure test, you’re likely to face the following issues:
  • Cooling system problems: If the cap is unable to maintain the proper pressure, you’re likely to develop issues with the rest of the cooling system. Your engine may overheat, the radiator hoses may collapse or burst, or you may notice coolant leaking from the system. 
  • Increased emissions: If the cooling system isn’t working properly, your engine performance will suffer. This can lead to a variety of issues, including increased vehicle emissions and reduced fuel efficiency.
  • Costly repairs: A radiator cap pressure test can help you catch serious issues before they cause severe damage. Neglecting this test can lead to extreme problems, like a blown head gasket and very pricey repairs. 

What is a radiator cap pressure test?

A radiator cap pressure test is a diagnostic procedure to check the functionality and integrity of a car’s radiator cap and cooling system. 
Automotive cooling systems prevent overheating by cycling coolant through the engine block and cylinder head. The coolant absorbs heat from the engine and sheds that heat in the radiator. The system requires a certain amount of pressure to increase the coolant’s boing point, boosting its ability to protect the engine from damage. 
The radiator cap is responsible for regulating the pressure in the system—it has a specified pressure rating and will not allow the pressure to fall too low or rise too high when working correctly. If the cap fails, the entire system may develop problems and fail to cool your engine. A radiator cap pressure test uses a special tool to observe whether the cap can maintain the specified pressure. 

When should I pressure test the radiator cap on my car?

There is no set testing interval for radiator caps. But some signs point to potential issues with the cap. These are the most common signs that you should pressure test your radiator cap:
  • Coolant leaks: If your car is leaking coolant, it could be a sign that your radiator cap is faulty. 
  • Overflowing coolant reservoir: If the cooling system pressure gets too high due to a faulty cap, the reservoir may overflow to relieve the pressure. 
  • Collapsing or exploding radiator hoses: If the pressure falls too low or grows too high, the radiator hoses may collapse due to the vacuum or explode due to excess pressure.
  • Engine overheating: If your car is leaking coolant or has air in the cooling system due to a faulty cap, the engine is likely to overheat.
Keep in mind: These issues can indicate other problems with the cooling system, like a faulty thermostat or a bad water pump. It’s always wise to visit a mechanic for a proper diagnosis. 

How often should I pressure test my radiator cap?

There is no universal interval for pressure testing car radiator caps. Your manufacturer may include this information in the recommended maintenance section of your
owner’s manual
. But, most of the time, you don’t need to pressure-test your radiator cap unless you see signs of cooling system problems, like coolant leaks or engine overheating.  

Can I pressure test my radiator cap myself?

A radiator cap pressure test can make an excellent DIY project. It’s a relatively entry-level job and even novices should be able to complete it with the right guidance. 
That said, if you’re uncomfortable handling coolant or dealing with the cooling system, you should contact a professional mechanic. 


The exact psi rating for your radiator cap will depend on your car’s make and model. The rating for most vehicles is between 13 and 16 psi.
To check for a bad radiator cap, follow these steps:
  • Let the vehicle cool
  • Remove the cap and visually inspect it for corrosion
  • Check the seal for cracks and brittleness
  • Perform a pressure test
  • Check for coolant residue around the cap
Outside of these steps, you should monitor your coolant level. If you notice leaks or drops in the level or your vehicle begins to overheat, you may have a faulty radiator cap.
If your radiator cap is bad, the best thing to do is to replace it with a new one. Radiator caps are relatively inexpensive, averaging $5 to $20 for a basic replacement, and are easy to remove and replace.

Meet Our Experts

John Davis
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Car Expert
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Certified mechanic with 10+ years of experience
John Davis is an expert automotive writer and former automotive mechanic. John's work spans multiple categories, and he relishes the opportunity to research a new subject and expand his area of expertise and industry knowledge. To date, John has written more than 200 articles covering car maintenance and care, car advice, how-to guides, and more.
Prior to joining Jerry’s editorial team, John worked as a mechanic and freelance writer, creating content for clients including HotCars and SetPower.
Jessica Barrett
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Car Expert
Jessica Barrett is a senior insurance writer and editor with 10 years of experience in the automotive and travel industries. A specialist in car insurance, car loans, and car ownership, Jessica’s mission is to create comprehensive content that car owners can use to manage their costs and improve their lives. As a managing editor for a team of writers and insurance specialists, Jessica has edited over 2,000 articles for Jerry on topics ranging from local insurance shopping tips to refinancing car loans with bad credit.
Before joining Jerry as a senior content editor in 2021, Jessica created visual content for clients such as Expedia, Vivid Seats, Budget Direct Car Insurance, Angie’s List, and HomeAdvisor. Her content was published in Business Insider, Forbes, Apartment Therapy, and the BBC.
Kathleen Flear
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Car Expert
Kathleen Flear is an expert insurance writer and editor who heads up Jerry’s editorial team as director of content. Kathleen empowers drivers to make smart car ownership decisions through  best-in-class articles on insurance, loans, and maintenance. Prior to joining Jerry in 2021, Kathleen served as managing editor for a team of SEO content marketing professionals at and worked as a freelance writer and editor for a range of digital publications, including Chicago Literati magazine and Golden Words. She earned a bachelor’s degree in English language and literature from Queen’s University, and a master’s degree in creative writing and fiction from Sierra Nevada University.
*The price information provided on our car repair webpages is intended for general informational purposes only. Actual prices for car repair services may vary based on various factors, including but not limited to the make and model of your vehicle, the extent of repair required, and the prevailing market conditions. All prices for real repair shops are estimations based on our research only. Therefore, the prices listed on our webpages should not be considered as final quotes or binding offers.