What Are The Best Radiator Pressure Tester Kits? (2022)

Best Radiator Pressure Tester Kit

Your car’s cooling system plays a vital role in keeping the engine from overheating. Unfortunately, an overheated engine can cause serious or even catastrophic damage. You want to identify any potential problems as early as possible.

A radiator test kit helps you diagnose leaks and other issues related to the radiator and cooling system. They identify external leaks, loose clamps, loose connectors, and more. Simple to use even if you’re a novice in the garage, radiator tester kits help keep your vehicle safe and in great working condition.

Here’s a closer look at some of our favorite radiator tester kits for 2022. New to using them? Check out our complete FAQ section for everything you need to know.

Our Top 3 Picks for Best Radiator Tester Kit

Our #1 Pick
Stant Cooling System Tester, Metallic
Mityvac MV4560 Automotive Radiator/Cooling System Pressure Test Kit, Contains Adapters to Test Most...
Honorable Mention
Astro Pneumatic Tool 78585 Universal Radiator Pressure Tester & Vacuum Type Cooling System Kit
Stant Cooling System Tester, Metallic
Mityvac MV4560 Automotive Radiator/Cooling System Pressure Test Kit, Contains Adapters to Test Most...
Astro Pneumatic Tool 78585 Universal Radiator Pressure Tester & Vacuum Type Cooling System Kit
Our #1 Pick
Stant Cooling System Tester, Metallic
Stant Cooling System Tester, Metallic
Mityvac MV4560 Automotive Radiator/Cooling System Pressure Test Kit, Contains Adapters to Test Most...
Mityvac MV4560 Automotive Radiator/Cooling System Pressure Test Kit, Contains Adapters to Test Most...
Honorable Mention
Astro Pneumatic Tool 78585 Universal Radiator Pressure Tester & Vacuum Type Cooling System Kit
Astro Pneumatic Tool 78585 Universal Radiator Pressure Tester & Vacuum Type Cooling System Kit

Radiator Tester Kit Reviews

1. Stant 30-Pound Cooling System and Pressure Cap Tester

A complete cooling system and pressure cap tester with a color-coded dial for simple, safe operation.


  • Safe, simple operation
  • Color-coded dial eliminates guesswork
  • Includes beginner-friendly instructions


  • Lens cover on gauge can be loose
  • Additional adaptors might be required for certain vehicles

Test your car’s cooling system without losing your cool. The color-coded dial helps even newbies easily and accurately test high-pressure caps and systems. The set includes a spacer which drops into the filler neck plus a cap adaptor for checking A-sized caps.

It also includes a pressure release bar. Turned clockwise, it releases pressure buildup to allow for safe removal. It tests pressure ranges of 17 to 19 pounds, 20 pounds, and 28 to 30 pounds.

All components fit securely into the included hard-plastic carrying case. The product also includes a detailed, easy-to-understand instruction manual.

2. Mityvac MV4560 Radiator/Cooling System and Pressure Test Kit

A simple, accurate, and affordable pressure test kit which is perfect for practically any at-home garage.


  • Accurate and easy-to-use
  • Durable, precise plastic construction
  • Adapters fit most domestic and imported vehicles


  • Doesn’t include carrying case
  • The tube needs a tight connection to the adapter

Not every kit needs dozens of pieces and options. Mityvac’s Pressure Test Kit product is a relatively simple kit which combines a hand pressure pump with four cooling system test adaptors and two dual-function test adapters.

It can easily detect internal leaks, defective caps, blown head gaskets, and other cooling system and cap problems. Adapters work for the cooling system and caps for most major U.S. and imported cars and trucks. The hose has a quarter-inch inside diameter and three-eights-inch outside diameter.

The tester is made from high-quality, durable plastic. All parts fit together well. Plus, the kit includes a complete instruction manual which details every step of the testing process.

3. Astro Universal Radiator Pressure Tester

Easy to use and versatile with color-coded test caps and a wide selection of adaptors which fit both domestic and imported autos.


  • Color-coded test caps
  • Caps are made from impact nylon with rubber seals
  • Connects to a wide range of radiator openings


  • Air compressor input port is cross-threaded (won’t fit all types of compressors)

Choosing the right test cap for your vehicle is easy with this color-coded kit from Astro. It features a specially designed vacuum purge and refill tool which connects to nearly all types of radiator openings. It fits Jeep, Subaru, Chrysler, Ford, Porsche and many more.

The caps are made from impact nylon with thick, rubber seals and o-rings. They not only fit most modern and classic vehicles but will fit on the billet aluminum caps found in many high-end vehicles.

The complete set includes a pressure testing pump with hose, a quick coupler, 17 testing caps, two black radiator cap test adapters, refill took kit, universal adaptor, temperature gauge and more.

4. 8MileLake 18-piece Radiator Pump Pressure Tester Kit

This 18-piece tester kit includes eight radiator caps which fit a wide range of foreign and domestic cars.


  • Fits a wide range of vehicles
  • Includes eight radiator cap adapters
  • The pump has a large volume with gauge


  • Cap can leak slightly
  • Difficulty fitting many Ford vehicles

Do you need to test multiple cars? 8MileLake’s18-piece kit works on Toyotas, Suzukis, Chryslers and many other vehicles.

It includes a pump with a gauge for testing pressurized cooling systems up to 35 PSI. The pump’s large volume reduces the time and effort needed to pressurize cooling systems.

If you find a leak, the kit includes eight radiator cap adapters so you can service your vehicle. All components fit securely inside the included carrying case.

5. Copap Cooling System Leak Tester Kit

A durable, reliable kit with color-coded cap adapters suitable for most major models of cars and trucks.


  • 14-piece testing kit for cooling systems, brakes and water tank
  • Includes pump, cap adapters, carrying case and more
  • Different colored caps


  • The manufacturer is relatively unknown

Check the cooling system, brake system, and water tank with this 14-piece testing kit from Copap. It includes a pump with gauge, thermometer, steel cap adapters, aluminum cap adapters, and a blow-molded carrying case.

The kit can be used on most foreign and U.S.-made vehicles. Each cap is a different color to help you easily select the right one for your vehicle. It’s a great combination of portability and versatility.

6. GoPlus 18-Piece Universal Radiator Pressure Tester Kit

A large kit with high-quality components including eight radiator caps and a special design which allows for short refill times.


  • 18-piece kit with eight radiator caps
  • Well-made, durable components
  • Caps have refill tool and vacuum purge
  • Kit fits a wide variety of radiators


  • 18 pieces is a bit large for home mechanics

This 18-piece for GoPlus is a good choice if you’re looking for a large, versatile, well-made kit which can withstand frequent use. Each tool is made from aluminum, rubber, and plastic.

The kit includes eight radiator caps with a test range from zero to 35 PSI. They have a vacuum purge and refill tool connection which fits practically all major types of radiator openings. It’s a good choice if you want easy leak detection combined with fast refill abilities.

7. EPAuto Spill Proof Radiator Coolant Filling Funnel Kit

A unique funnel used for a coolant flush which helps prevent spills and identify leaks.


  • Unique kit designed for coolant flushes
  • Prevents air pockets and spills
  • Simple, easy-to-use design


  • Not a complete test kit

Coolant flushes help keep your cooling system working effectively. But performing a coolant flush can be messy if you use a traditional funnel. This unique filling funnel kit from EPAuto is designed specifically for a coolant flush.

The funnel prevents trapped air pockets from entering the cooling system. Plus, it has a unique design which prevents spills. The pressure test kit includes a lid, funnel, five-inch extension bar, 45-degree elbow and a wide range of caps.

8. Kauplus Radiator and Cap Test Kit

A simpler, smaller kit which helps you identify potential links in the radiator systems of domestic and foreign cars.


  • Includes hand pump and tester head
  • Allows for fine pressure adjustments
  • Effectively identifies radiator leaks


  • Includes a relatively small number of caps

While it doesn’t have as many components as some of the others on our list, this radiator, and cap test kit from Kauplus is an easy and effective way to test for leakage. It includes a hand pump, tester head with a 12-inch hose, gauge and more.

It also includes a 32 mm ID cap system with both 9.5 mm and 15 mm depths. The cap’s rotating lever allow for fine pressure adjustment and controlled pressure release. It can test cooling systems up to 30 PSI.

9. MotoRad MT-300 Pressure Tester

A large, heavy-duty gauge with color-coding capable of reading up to 30 pounds.


  • Durable construction
  • Color-coded gauge
  • Quick release safety bar
  • Made in USA


  • Instruction manual’s sizing guide can be confusing

With high-quality construction and a heavy-duty gauge, this American-made pressure tester from MotoRad will likely last a lifetime.

It has a color-coded gauge with a large display which can read up to 30 pounds of pressure. The gauge displays the readings in both kpa and pounds.

It’s safe, too. Twist the release bar to quickly and steadily drop the pressure in case of an emergency.

Radiator Pressure Tester Kit FAQ

What are Radiator Pressure Tester Kits?

Radiator pressure tester kits are an easy, accurate way to identify, diagnose and repair leaks and other potential cooling system problems.

The kits duplicate the pressure level of a running engine. You can watch how the cooling system runs even though the engine itself is off. It creates a safe, controlled environment for you to examine the cooling system – as in, you don’t have to stick your face into a running engine.

In order to understand why regular radiator tests are important, let’s take a closer look at your car’s cooling system.

What Does the Cooling System Do?

Without a properly functioning cooling system, your car’s engine won’t run for long. Coolant flows through the system to keep your car from overheating. But your car’s cooling system is vulnerable to leaks, and even a minor one can cause major engine overheating.

Unfortunately, detecting leaks isn’t always so easy. The hoses for your system run throughout your car, and you can’t see everything. Many cooling system and radiator problems go undiagnosed until they turn into a situation involving costly repairs or even catastrophic failure.

At the heart of your cooling system is coolant. It’s a 50/50 mixture of antifreeze and distilled water. Each make and model of vehicle requires a different amount of coolant. Check your owner’s manual for details.

Coolant flows through your engine whenever it’s running. As it moves through the engine, it’s absorbing the engine’s heat.

The radiator is a heat exchanger. As the coolant flows over the radiator, it’s cooled down. The now, well, cooler coolant is returned into the engine, where it absorbs more heat, eventually returning to the radiator to repeat the process.

Here’s some quick science:

  • Engine temperatures run between 180 and 205 degrees.
  • Water boils at 212 degrees
  • Coolant boils at 223 degrees

The coolant’s higher boiling point allows the engine to run at the high temperature required for optimum efficiency. For example, when the system is under 15 PSIs of pressure, the coolant’s boiling point is 260 degrees. The engine can operate in a variety of conditions, gears, situations, etc. and the coolant won’t boil away — so the engine won’t overheat.

What’s the Best Type of Tester Kit?

Kits can be divided into two types:

  • A kit for use on a single vehicle
  • A kit for use on multiple different makes and models

The less expensive kits typically only work on just a few makes, such as Fords, Subaru, etc. Other types are limited to a manufacturing region such as the U.S., Europe, or Asia. Typically, radiator caps will have a secure but somewhat generic fit.

Kits for use on multiple different types of cars are often the highest quality type of kits. They have multiple different caps. You can find a precise fit for your vehicle’s exact make and model.

Plus, multi-car tester kits are generally made with high-grade materials and include extra features. Most people are better served by buying a tester kit which can test a wide range of vehicles.

What Features Should I Consider?

Not all testing kits are the same. Here’s what to look for:

Ease of Use

If you’ve never used a kit before, buy one with clear instructions and color-coded radiator test caps. Each cap is colored according to the car model it fits on.

If you’ve never seen test caps before, they’re pretty hard to tell apart based on the model. Different colors are a simple, practically guaranteed way to know you’re using the right one.

Pressure Rating

Pressurization moves the coolant through the system. Most cooling systems are under 10 to 20 PSIs of pressure. You can also add extra pressure to the system by using special radiator caps (although that’s not recommended unless you know what you’re doing). The pressure rating of the kit should be the same as the rating listed on your radiator cap.

Refill Tool

Refilling coolant can be surprisingly difficult when using a standard funnel. You have to make sure air bubbles don’t become trapped inside the coolant system. Many tester kits include a special refill tool which automatically prevents air bubbles from entering the system when adding coolant.

Oddly, radiator refill kits are often more expensive to buy separately than when included as part of a tester kit.

Quick-Snap Connectors

The best testing caps have self-locking, quick-snap connectors. They make connecting components fast and easy. Plus, self-locking caps are the most secure option, so they help prevent accidental pressure loss.

How Do I Use a Testing Kit?

Never use a testing kit on a running or even a warm car. Also, allow the engine to cool to the touch before opening the radiator cap. Otherwise, the hot liquid inside can spray out and cause serious injury.

Additionally, make sure the cooling system is no longer under pressure. Squeeze the upper radiator hose. If it’s stiff and solid, it’s still under pressure. Wait until the hose is easy to squeeze before opening the radiator cap.

Always test a full cooling system. The reservoir has a line indicating the maximum fill level. Fill it as precisely as possible to ensure accurate test readings.

Double-check the pressure rating for safety. The PSI of the tester shouldn’t exceed the PSI on the radiator cap. Otherwise, serious internal damage could occur.

Select the cap. This will be easy if you have a color-coded kit. Secure the cap to the radiator. You’re now ready to begin the test.

During the test, check the engine for any signs of leaks. Use your eyes, ears, and nose. Some hoses within the cooling system are hard to see. Listen for dripping noises. You might be able to smell coolant leaking, too.

Watch the pressure gauge. If it drops more than a few points, especially immediately, you might have an internal leak, which can signal a blown head gasket. A pressure drop without any signs of a leak should be taken seriously.

After testing, release the pressure before removing the cap. Most kits have a pressure release valve. If yours doesn’t, twist the cap slowly to release the pressure manually.

Finally, don’t forget to check the radiator cap. If you’re losing coolant, but can’t figure out why, the radiator cap might be faulty.

All in All

Don’t get stuck on the side of the road with an overheating engine. A radiator pressure tester kit is the best way to identify and prevent problems with your vehicle’s cooling system. They’re simple, easy to use and can be a literal lifesaver on the road!

Brett Gordon

The engine behind editing at DigMyRide and the brains behind its build. During the day, Brett is a thirty-something dude from SoCal climbing the corporate ladder, but by night, he spends his time contributing to the online world of automotive tech & trends.