How to Check for Air Brake Pressure Problems
Almost all large commercial vehicles on the road today are fitted with braking systems that rely on compressed air. These systems are designed to cope with a challenging environment and will typically work well without too much intervention. However, issues can arise as with other mechanical systems, and it's important to understand where some of these problems may materialise. If you are unable to use your truck because you cannot build up the correct level of air pressure, what could be going wrong?
Under Pressure
As you know, you're not supposed to operate a commercial vehicle of this type unless you have carried out some pre-trip checks in the depot. You're supposed to turn the vehicle on and check to see that the right amount of air pressure has built up by looking at the dashboard gauge. If you cannot build the correct pressure, then you will need to look for the cause and repair it before moving off.
Compressor Pipes
The first place to look is the compressor and, specifically, the inlet and delivery pipes. Check to see if these have been crimped or whether there is a leak in either one of the pipes. You should also check the delivery pipe for the presence of any excess carbon as this may have a tendency to build up.
Inspect the Valves
Next, have a look at the unloader valve to check for the presence of a leak. There is typically a series of valves along the delivery line, and each of these may need to be checked to determine whether air is leaking from one of the ports. You should also double-check the pressure cut out on the primary valve to make sure that it is set at the appropriate level.
Check for Leaks
If you are unable to find an answer to your problem right away, you can perform a workshop check to see if you can find a leak elsewhere in the braking system. To do this, you can connect a pressurised air supply line to the inlet port. Once you switch this on and turn the engine off, you can detect the presence of any leaks and pinpoint the problem spot.
What to Do Next
If you are still at a loss to explain the problem, then you should certainly take the vehicle to a truck repair technician. They will have experience in this area and will be able to get to the source of the issue as soon as possible.
