Sierra Pressure and Vacuum Tester 18-99530, Combination Marine Engine Diagnostic Tool

The Sierra Pressure and Vacuum Tester (18-99530) is a combination diagnostic tool that lets a technician perform both pressure testing and vacuum testing with a single unit, eliminating the need for two separate testers. A valve on the side of the gauge housing switches the tool between pressure mode and vacuum mode, so fuel pumps, cooling systems, crankcases, and other marine engine components can be checked for leaks, blockages, or improper operating pressure without swapping tools mid-job. The gauge housing is built from a metal and plastic combination for durability in a shop or dockside environment, and the fittings use NPT thread style for compatibility with standard marine and automotive test points. The kit is supplied complete and ready to use, including a hose assembly and two adapters, so it can be connected to a variety of test fittings out of the box. At 10 x 11 x 3.4 inches and 2.2 pounds, it is compact enough to store in a tool box or service kit while still offering a full-size gauge face for accurate readings. This tester is intended for marine technicians and serious DIY boat owners who need a reliable way to verify fuel system pressure or check for vacuum leaks as part of routine engine diagnostics and troubleshooting.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99530
• Item Type: Pressure and Vacuum Tester
• Function: Combination pressure and vacuum testing in one unit
• Thread Style: NPT
• Material: Metal, Plastic
• Item Dimensions (L x W x H): 10 x 11 x 3.4 inches
• Weight: 2.2 pounds
• Number of Items: 1
• Included Components: Hose assembly and two adapters
• Category: Specialty Tools

Frequently Asked Questions

What does the Sierra 18-99530 tester actually do? It performs both pressure testing and vacuum testing in a single gauge unit, so one tool covers checks that would otherwise require two separate testers.

How do you switch between pressure and vacuum modes? A valve on the side of the 18-99530 gauge housing is flipped to change the tool from vacuum mode to pressure mode, with no disassembly required.

What is included with this tester? The 18-99530 kit ships complete with a hose assembly and two adapters, allowing it to be connected to test points right out of the box.

What are the dimensions and weight of the unit? The Sierra 18-99530 measures 10 x 11 x 3.4 inches and weighs 2.2 pounds, making it compact enough for a standard tool box or service kit.

What is the gauge housing made of? The housing combines metal and plastic construction, giving the 18-99530 durability for regular shop and dockside use.

What thread style do the fittings use? The 18-99530 uses NPT thread style fittings, matching standard marine and automotive test connections.

Is this tester suitable for checking fuel pump pressure? Yes, the combination pressure and vacuum function of the 18-99530 makes it suitable for verifying fuel pump output pressure as part of routine engine diagnostics.

Can this tool check for vacuum leaks in cooling or crankcase systems? Vacuum mode on the 18-99530 lets a technician check for vacuum leaks or improper vacuum readings on applicable engine systems.

How many gauges come in the box? The 18-99530 is supplied as a single combination gauge unit rather than two separate pressure and vacuum gauges.

Is this a professional-grade tool or for occasional home use? The metal-and-plastic build and included hose and adapters make the 18-99530 suitable for both professional marine technicians and DIY boat owners doing their own diagnostics.

Does the tester come with a warranty? The Sierra 18-99530 is covered by a limited warranty.