Over the past year, the engineers at Vacuum Instrument Corp. have designed numerous leak testing systems for assemblers of all sorts of products. Here are three from the automotive industry.

Engineers at Vacuum Instrument Corp. designed an innovative leak testing system for an exhaust gas recirculator cooling system, like this one.

Over the past year, the engineers at the Air Leak Testing Div. of Vacuum Instrument Corp. (VIC, Ronkonkoma, NY) have designed numerous leak testing systems for assemblers of all sorts of products. Here are three from the automotive industry.

One was a turnkey project for testing gear housings. The system tests five different gear housings. The system uses a mass-flow leak testing instrument, which minimizes test errors related to fluctuations in part volume. Parts can be loaded into the system automatically from the top or manually from the front.

First, the part is placed onto a carriage. Then, the part shuttles to the test position. Seals automatically extend and a leak test performed. When the test is completed, the part returns to the operator for unloading. The leak test specification is 5 standard cubic centimeters per minute (sccm) at 5 psi, and the cycle time is less than 45 seconds.

If three consecutive parts in a row are rejected at the same fixture, the system tells the material handling system to stop loading parts and signals the operator to check the fixture seals. In addition, at preprogrammed intervals, the system requests the master part to be loaded for testing. The material handling system retrieves the master part from storage, and places the part in the fixture.

VIC Leak Testing also supplied a leak tester to check brake caliper assemblies primarily used on motorcycles.

The instrument uses air to test the caliper assemblies at low pressure (5 psi) and high pressure (1,300 psi). The low-pressure leak test is used to detect cut O-rings that would normally seal at high pressures. The high-pressure test is used to determine the integrity of the entire assembly.

The brake caliper is assembled in the fully retracted position. During leak testing, the pistons are extended to a dimension determined by the thickness of the pads and rotor. (A spacer is installed during the test to simulate the rotor.)

The leak rate specification is 3 sccm for the low-pressure test and 11 sccm for high-pressure test.

A third system was designed for testing cooler assemblies for an exhaust gas recirculation component. The system uses the helium accumulation test method to check both the water and exhaust side of the cooler during the same test cycle.

Testing is accomplished by loading the cooler into the chamber and starting the cycle. After sealing, the exhaust side is checked for gross leaks using a vacuum-decay leak test. Then, it’s charged with helium for the helium leak test. The sniffer probe that is integral with the accumulation chamber measures the helium concentration over time in the test enclosure, and the leak tester detects the helium. After the exhaust side is tested, the system removes any helium from the chamber and seals the water side. The water side is then tested in the same way.

The leak specification was 0.01 atm cubic centimeters per second at 30 to 40 psi. The cycle rate was 95 parts per hour.

For more information about leak testing, call Vacuum Instrument Corp. at 631-737-0900 or visit www.vicleakdetection.com.