Help! How Is Anyone Supposed To 'accurately" Read An Air Pressure Gauge Like This One?

RE:

You are way over thinking this. The gauge is set up for the numbers you need. 90, compressor comes on. 120, compressor cuts off. 60, warning buzzer comes on. 30, valves should pop.

Actually not. CA CDL Manual says:

"*Air Compressor Governor Cut-In Pressure Test To perform this test, the air pressure for the vehicle cannot be rising when the engine is running. With the air pressure at maximum pressure (cut-out), begin slowly pumping the brake pedal to reduce the air tank pressure. Watch the air pressure gauge between pumps to identify when the compressor cuts-in (needle starts to rise). This must occur no lower than 85 psi for a bus, and no lower than 100 psi for trucks."

Just sayin.

Anyway I was hoping for someone who has experience with the specific gauge scale as what I have to test with to chime-in.

Thanks to all for trying... ... But no cigar

Fair enough, although my state's manual states at "around" 100 psi. Basically if the needle drops below the obvious 90 mark and the compressor doesn't come on, there is a problem.

What do you think is going to happen on the test? The tester will not expect you to tell the exact number on the gauge when the pressure stabilizes and the exact number after the minute is up. You do not have to say "pressure has stabilized at 101 psi, after one minute the pressure is holding at 99 psi." They are looking for the phrases they want to hear and your instructor should have taught you. For example, as you're fanning the brakes, they want to hear "the low air warning light and buzzer will come on at or before 60 psi." They do not expect to hear "the low air warning light and buzzer came on at 64 psi." You are getting yourself too worked up over this.

However, this does bring up a question. Since those of us who have actually passed the in cab air brake inspection part of the cdl test, and who manage to successfully read our air gauges dozens of times every day, don't know what we are talking about, why don't you ask your instructor, WHO HAS EXPERIENCE WITH THAT SPECIFIC GAUGE SCALE?

You are not being tested on whether you not you can read the gauge, you are being tested on if you know how to perform the brake tests and what numbers you need to know. The tester is sitting in the passenger seat with a non perfect view of the gauges. Mine never even looked up from her computer, she just wanted to hear the litany i learned that had all the gauge positions I needed to know and that I could perform the actual tests.

Anyway I was hoping for someone who has experience with the specific gauge scale as what I have to test with to chime-in.

Thanks to all for trying... But no cigar

Soulin, aside from my mistake, you were given the correct answer. Your reading of the manual is leaving you confused. It's petty obvious from your prior posts that you are a really detail oriented person. You always want everything figured out right down to the minutiae of the details. You were already wanting to have a full working knowledge of the "split sleeper berth" rule before even getting started. That's a detail many experienced drivers don't even understand.

You quoted the manual with all it's detailed information, but ignored the advice from the people who've already passed all the tests your concerned about. They are experienced, and you carelessly ignored their information with your "no cigar" comment. The fact is, if your losing "more than" 3 or 4 psi per minute, you'll be able to tell because that needle will be moving down. It will be visibly noticeable to you. If it's not losing air it will hold steady. It's only a sixty second test. Relax, you don't need single psi increments to look at. You'll know if it's working properly without having to get all anal with the details.

I understand your obsession with details, I can be that way. You just can't let it get the best of you in this job. Very few things are perfectly accurate in this career. You will discover that no two trucks air compression systems act identically. The compressor will cut on or off at slightly different pressures, or the air pressure may bleed down more over a ten hour break period in one than it does in another. They're both working properly and safely, but differently. The manual may sound rigid, but reality is somewhat flexible.

Try to relax and not drive yourself crazy by overthinking the details. This probably sounds unprofessional to you now, but about three years into this career you'll understand me. Of course, if you think I'm crazy now, and continue stressing over the minutiae, you'll never last three years in this job. It will drive you nuts.

The main point of the testing, is that you know how to verbalize the correct information to the officer while you're demonstrating the proper steps to take the test. They are already expecting you to show up in a properly inspected truck that's in good working order. They just want to see you demonstrate the test properly, and verbalize the information correctly.

WHO HAS EXPERIENCE WITH THAT SPECIFIC GAUGE SCALE???? Come on now, it's not some rocket science. You are being given way more information than you really need about the gauge. As is being said don't over think it. When I had to take the air brakes test the guy was on the phone with his wife. Not in my lap watching the guage. But more importantly ASK YOUR INSTRUCTOR. This is what they are there for. To be able to give you a hands on review on it and for you to ask him these questions till your hearts content.

The main point of the testing, is that you know how to verbalize the correct information to the officer while you're demonstrating the proper steps to take the test. They are already expecting you to show up in a properly inspected truck that's in good working order. They just want to see you demonstrate the test properly, and verbalize the information correctly.

Thanks Old School. That is the most accurate and truthful 'answer' I have read here for this topic and is what my instructors have been saying all along. As of yet, I have not read any posts beyond the one the quote above is from yet.

As for my instructors' they have been very informative and have answered every question I have asked. Yes, I have asked about the air pressure gauges. The answers I have gotten regarding that so far have not been specific but were general about having to 'learn' the increments; And yes, there is a worded 'script' we are supposed to remember for the Air Brake Test at the DMV.

It's only a sixty second test. Relax, you don't need single psi increments to look at. You'll know if it's working properly without having to get all anal with the details.

LOL!! More paranoia than anal.

I am just looking for accurate answers regarding the specific gauge I have to test with. I have received mostly 'accurate' answers and good advice here; (thanks to all for that). There has been at least 1 incorrect answer, Re: "Static Leakage Test"; for example:

For the static leakage test your basically just watching to make sure the needle doesn't continue to drop as your holding the brake.

, ...But, no answers specific to the gauge I am asking about.

It is a definite fail at the DMV on the Air Brake Test to press the "Service Brake" and reefer to it as the "Static Leakage Test".

Anyway I was hoping for someone who has experience with the specific gauge scale as what I have to test with to chime-in.

Thanks to all for trying... ... But no cigar

Seriously?

I reused the term you used in your original post so you wouldn't be confused. I am fully aware of what the test is called.

Your specific gauge scale is no different than the ones in our trucks. No special experience is needed.

Your on a forum full of people who have already passed this test and your going to claim we can't help you with "Thanks for trying....But no cigar"??????

Every reply in here had been accurate with the exception of Old School mistaking the gauge for a brake application pressure gauge at first.

If you are going to hold it against me that I reused your phrasing in the original post I don't know what to tell ya... I guess my mistake was trying to make it easy for ya.

You seem to be by the book to a fault.

The airbrake test is simple, it's only the specific verbage that confuses people. If you understand what exactly you are testing for, then the verbage starts making more sense and is easier to remember.

Step one is simply checking for leaks. Your holding the brake down while listening for leaks and making sure the pressure does not continue to drop while you are doing so.

Mr/Mrs Evaluator I am going to depress the brake and wait for the gauges to stabilize. (Point to gauges) I will be checking to make sure I do not lose more than 4 psi in one minute, while listening for air leaks.

Step two is just making sure your warning air pressure warning system is working properly. You pump the brakes down to the warning limit and make sure they come on.

Mr/Mrs Evaluator I am going to pump down on the brake pedal until the warning light and buzzer come on at or before 60psi.

Step three is making sure the air valves are working properly in the event of a loss of air pressure.

Mr/Mrs Evaluator I am going to continue pumping down the brake pedal until both the tractor protection valve and the parking brake pop out between 40 to 20psi.(make sure they both pop out and not just one)

The test is easy. Stop worrying about the gauge and just keep repeating the verbage until it's burned in your brain.

Your on a forum full of people who have already passed this test and your going to claim we can't help you with "Thanks for trying....But no cigar"??????

Yeah, this guy is gonna be a real treat to deal with. Wait until he gets on the road one-on-one isolated with his first mentor. He's gonna give one or two smartass remarks like that and on the second day find himself sitting on the side of the road hitching a ride.....with no cigar.

I think I see where some of the confusion is coming from. I just noticed he is quoting stuff from the CA book. I know CA has a habit of doing things "different" so I looked it up. Seems CA has a couple extra steps to it's air brake test.

This guy gives a decent demonstration.

https://youtu.be/8t0F2ZWXLsU

Your on a forum full of people who have already passed this test and your going to claim we can't help you with "Thanks for trying....But no cigar"??????

Yeah, this guy is gonna be a real treat to deal with. Wait until he gets on the road one-on-one isolated with his first mentor. He's gonna give one or two smartass remarks like that and on the second day find himself sitting on the side of the road hitching a ride.....with no cigar.

That’s exactly what I was thinking.