Pre-trip Brake Test mnemonic

L-leaks

A-Alarms

B-Buttons

 

Sometimes
Fast
Trucks
Tend
To
Roll

 

Ok let's go through a brake test as it should be carried out: You start by pulling open your hood and checking your oil before starting your truck. then go around to your fuel tanks and find your water bleed off value, most have a small cable hooked to them, pull the cable and you will hear air bleed off and try watching the value and you can see water being sprayed if no water only air that's good now go to the other side and do the same, this works only if you have air pressure but if no air pressure this can wait until you have built up your air. After you enter your truck find your two brake control buttons, they are colored red and yellow. now find your air pressure gauges, most likely they will show air pressure over 60 PSI then make sure both brake buttons are pulled and that's park position. IF you have air pressure turn on your ignition switch if air is below 60 PSI you may hear a low air warning buzzer. Start your truck and watch your air gauge let the pressure build up then cut truck off and put truck in reverse if on level ground now push both buttons in but make sure truck does not roll. If truck don't roll then start pumping your brake until you have no air pressure. Two things will happen below 60 PSI your brake will auto set and you should hear low air buzzer. Look at your gauge while pumping brakes and you will see what pressure your brakes set, air pressure holds both parking brakes out until there is low air pressure. When you have no pressure or low and both these things have happened then start you engine, don't race your engine just bring up RPM a few hundred to help the air compressor you now look for two things, recovery time and where your low air buzzer stops. When over 60 PSI your buzzer should stop and your brake away values will become active, pull both and reset then if your truck is on level ground push both park brakes in and again put truck in reverse and stop engine. Look at your air pressure gauge and it should be holding with engine off and you should not hear an air leak. If truck is secure and engine is off and both buttons are pushed in air pressure should be holding if not you have an air leak. If you have an air leak it could be something as simple as glad hands are not hooked up proper. At this point this is for the company mechanic to check. Set your brakes put your truck in gear and report problem. Now some trucks don't have a low air warning buzzer and they have what is known as a wig wag, this is a device that falls down into view of driver letting you know you have low air. The reason some trucks have this is to keep the driver from turning the truck at high rpm to build up air pressure, they don't like to hear buzzer. That's it.