4" Universal Turbo Boost Leak Tester Kit - Billet Aluminum - 30 PSI Gauge - Find P0299 Boost Leaks

The 4-inch universal boost leak tester is our best-selling kit. It clamps over a 4" turbo compressor inlet, or onto a 4" intake pipe in front of the turbo, so you can pressurize the whole boost path with shop air while the engine is off. Find leaks in couplers, charge pipes, the intercooler, throttle body, vacuum lines and BOV before they cost you power, fuel economy or a turbo. Boost leaks are the most common cause of a P0299 underboost code.

What it fits

• Any turbo inlet or intake pipe that measures 4" across the outside. Measure straight across the opening with a tape measure or calipers.
• Gas and diesel engines.
• Not sure of your size? See What size do I need?, or text a photo of your turbo inlet with a tape measure across it to 248-403-8512 and we'll tell you the size.

What's in the kit

• Billet 6061 aluminum end cap, CNC machined, with 1/8" NPT gauge and fitting ports
• High-quality silicone coupler
• Custom stainless steel 30 PSI / 2 bar boost gauge
• Universal tire Schrader valve, so you can fill it with a tire inflator (a compressor fitting comes with the extension hose kit)
• (2) stainless steel T-bolt clamps with Teflon lock nuts

Why the boost gauge matters

Testing without a gauge is like filling a tire without one: you don't know how much air is in the system. Unregulated shop air at 90 PSI can over-pressurize the charge pipes, and the tester or another part of the engine could blow off. The 30 PSI range reads low, medium and high boost levels, and the gauge lets you:

1. Apply a safe amount of pressure to prevent injury or damage to the charge pipes or engine.
2. Read how fast the system holds and bleeds air after you remove the air source.
3. Compare compressor outlet pressure with test pressure while filling. The smaller the difference, the less air the system is losing.

How to use it

1. Remove the intake hose or pipe from your turbo inlet.
2. Install the boost leak tester on the turbo inlet and secure it with the T-bolt clamps.
3. Pressurize the tester with an air compressor and a tire inflator. Use a compressor of at least 2 gallons; a bike pump or electric pump will not supply enough air fast enough to fill the system.
4. Caution: start at a low pressure, around 5 PSI. Regulate the compressor to a lower pressure and only increase it if filling is too slow. It is normal to see an average pressure loss of about 1 PSI every second after you remove the air: faster at higher pressure, slower at lower pressure.
5. Listen for leaks. Use soapy spray to find smaller leaks.
6. Fix any leaks and retest. Increase 5 PSI at a time, up to your normal operating boost.
7. Go out and boost, and enjoy the restored power.

Every turbo owner should have one. It's a must if you're tuned or getting a custom tune, any time you replace intake tract parts such as charge hoses, the intercooler, manifold, vacuum lines or injectors, and before track days so you know everything is tight enough to handle sustained boost.

Add an extension hose kit

A 5 ft extension hose with a shut-off valve gives you control over shop air and the pressure going into your turbo system, and it's a must in a shop where the compressor isn't within reach. Closing the valve traps the pressure so you can watch the bleed rate, which tells you how well the system holds.

• 5 ft extension hose kit with shut-off ball valve
• 5 ft extension hose kit with shut-off valve and 150 PSI regulator

Lifetime warranty

Every component is covered for life: break it and we will replace it. Orders ship the same day, and tech help is a text away at 248-403-8512.

New to boost leak testing? Read how to do a boost leak test and the instructions for universal boost leak testers, or see all of our boost leak testers.

Helpful guide: P0299 code: causes, symptoms and how to fix it