Air Break Practice Test – Page 5

Results

#1. When you test the system air-loss rate, the maximum acceptable leakage rates per minute for a straight truck, a tractor pulling one trailer, and a tractor pulling two trailers are

3, 4, 6 psi respectively.

2, 3, 9 psi respectively.

4, 4, 6 psi respectively.

1, 2, 3 psi respectively.

In British Columbia, the maximum acceptable leakage rates per minute are 28 kPa (4 psi) for single vehicles (buses, straight trucks and bobtail tractors) and tractor-trailers with one trailer, and 41 kPa (6 psi) for tractor-trailers with two trailers. If the leakage rate is higher, check for leaks and correct them.