Air Leak & Air System Repair
A truck that won’t build air pressure isn’t going anywhere — brakes need it to release. We work through the system in order: compressor, dryer, tanks, then lines, instead of guessing at the source.
Symptoms we see
| Symptom | Likely cause | What we do |
|---|---|---|
| Air pressure won’t build at all, or builds very slowly | Air compressor failure, a major line leak, or a failed governor | Check compressor output and governor function first — biggest sources first |
| Audible hissing near the wheel ends or chassis | A leaking line, fitting, or brake chamber diaphragm | Soap-test the system to pinpoint the exact leak location |
| Air dryer cycling constantly or purging excessively | Worn dryer cartridge or a failing purge valve | Inspect and replace the air dryer cartridge — a top PM item |
| Pressure drops noticeably overnight | Small leak somewhere in the system, often at a fitting or a brake chamber | Pressurize the system and check for leak-down rate, then locate the source |
SymptomAir pressure won’t build at all, or builds very slowly
Likely causeAir compressor failure, a major line leak, or a failed governor
What we doCheck compressor output and governor function first — biggest sources first
SymptomAudible hissing near the wheel ends or chassis
Likely causeA leaking line, fitting, or brake chamber diaphragm
What we doSoap-test the system to pinpoint the exact leak location
SymptomAir dryer cycling constantly or purging excessively
Likely causeWorn dryer cartridge or a failing purge valve
What we doInspect and replace the air dryer cartridge — a top PM item
SymptomPressure drops noticeably overnight
Likely causeSmall leak somewhere in the system, often at a fitting or a brake chamber
What we doPressurize the system and check for leak-down rate, then locate the source
What the job involves
We check the compressor and governor first — if the truck isn’t producing air fast enough, nothing downstream matters yet.
The air dryer gets inspected next since a worn cartridge causes both slow pressure build and moisture problems that damage other components over time.
We soap-test lines, fittings, and chambers to find the actual leak rather than replacing parts on a guess.
Once the leak is fixed, we verify pressure builds and holds to spec before the truck goes back out — this is an emergency call, and we don’t want you back on the shoulder tomorrow.
What drives the cost
What this costs depends on whether it’s the compressor, dryer, or a line/fitting leak, how many leak points are found, and whether a component needs replacement or just repair. We tell you after we look at it, before we start.
Common questions
My truck won’t build air pressure — what’s first to check?
The compressor and governor. If air isn’t being produced fast enough, nothing else in the system matters until that’s fixed.
Can a small air leak really strand a truck?
Yes — brakes need air pressure to release. A leak that outpaces the compressor means the truck won’t move safely.
How do you find a leak that’s hard to hear?
We pressurize the system and soap-test lines, fittings, and chambers to pinpoint it exactly.
How often should the air dryer be serviced?
It’s a top PM item — worth checking at every major service interval, not just when there’s a problem.
What does an air leak repair cost?
Depends on the source and how many leak points we find. We diagnose before quoting.
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Service area
Ready when you are
Call now or send a quote request — we’ll tell you what it takes to fix it.