DOT Inspection methods

You could be right on tractors but I've got a Trail King trailer that specificity states in the manual, that if you have a blown bag, to just drop the air and you'll be ok to run it.

I'm not saying to just keep running, but you should be ok to at least drive to the repair facility.

 

A trailer would make no difference you a correct- but you would also have to block the line to the bag.

I have seen driveshafts and other things destroyed doing this very thing with a load. Depends on the application and situation I'm sure. I agree if your careful most likely your OK.

 

My trucks losing 30 psi from both tanks simultaneously regardless of whether the breaks are set or released or engaged or not. Loud audible leak coming from the air compressor itself, but leak stops when air gets to 90 psi.

 

So does this happen when the primary or secondary tanks are above 90?

In general most times an inspector does a level 1 or 2 inspection. and does the break check, they will have you go to what is it? 100 to 110 or so. For good measure. Then shut down your engine.
Put the key to the on position, when all the gauges come up and are ready, with breaks secured and not touching the service break pedal. Do you loose air down to 90psi?

If not the test general goes, release your breaks. (Chalk wheels or at least be on flat ground and check behind you first.)

When breaks are released you will normally loose some psi. (But not much) The when that is done your told to hold down the service break and the I specter generally could for 1 minute. To see how much psi you loose. Is this whe your dropping to 90 psi? Or just when ever you go above 90?

If you make it the last part and your not loosing air then that's good. It could be an older modal truck maybe? Or a host of other issues. But! If you do loose to much psi during the test. That would be a sign of a leak and could be places oos,

If the leak is easy to hear like you said
Were is is co.ing from on the compressor? If it's the drain valve then again it could put you oos, and needs to be checked by your mechanic. If it's a hose. It's a hole. If it's at a push in connector. Per the regs that should not be a violation of any kind unless the truck as a whole fails the break check.

As so.e of the very old posts I. this thread mention about the mechanical skills of an inspector. To my knowledge, inspectors will not be mechanics. Some might be former drivers ect some times. But the rules for this stuff is fairly black and white. If they can't find the leak but your hearing and the psi is dropping to much. They are bot required to find the exact location. Only record that the vechile failed the test.

Remember most inspectors that are not full time police or troopers are paid an hourly rate far lower then LEO's that are also Inspectors. And well, 95% of states are not going to pay to send them to more training classes then is needed for the CVSA certs sadly, lol.

But honestly, find were on the tank the leaks at. Hose, valve or maybe a tiny crack In the tank is self,
At the very least you can get it looked at before it causes you to loose time on a run, or cost you or the company more money in repairs because it got worse down the road.

 

Where at the compressor is it coming out? The governor, or the compressor?

I’ve seen the unloader valves in the compressor go bad. It won’t leak at all while the compressor is pumping, but when the compressor stops pumping it will leak air out the compressor intake. You can tell on your gauge that it will build to 120, drop quickly back to around 90, and then the compressor will kick back on. With the truck shut off it will drop quickly to around 90 psi and stop.

 

oh my dear god

 

If your truck can’t hold air pressure, you’ll be placed OOS. The officer isn’t going to crawl under your truck with a bottle of soapy water and diagnose your problem.

 

Wot? After fighting seasons of winter slop, Monsoons and tornados etc? A dab of spritz water and soap mix shows Mr Bubble telling you where Mr Leak is at.

 

Other than audible leaks of hoses, tubing and chambers this is the OOS criteria.

Air Loss Rate

If an air leak is discovered and either the primary or secondary reservoir pressure is not maintained when: (396.3(a)(1)

1) Governor is cut-in;
2) Reservoir pressure is between 80 – 90 psi (551 – 620 kPa);
3) Engine is at idle; and,
4) Service brakes are either fully applied or released.

 

On all trailers i know adjust the braking according to the pressure on the airbags.
Second issue is that if you run with dropped airbags the weight will not be divided equally on your axles,again leading to brakes that are not working correctly.

So if you dropp your airbags your brakes are not working as they should.
So it is not safe.