Air brakes

[03heritagerider]

I obviously have a leak somewhere in my air line system. Went to start the coach today and the "low air" buzzer would not stop. The front and rear air gauges are at zero and the air bags will not inflate.

I ran the engine and crawled under the coach and basement to try to hear a leak, but heard nothing.

How do I find the leak?

[Chuck v]

Seems pretty unlikely that both front and rear air systems would have leaks sufficient to not build any pressure anywhere -- have you checked the pump itself?

Here is a very informative slide show from classes Freightliner teaches -- including the speaker notes:
http://freightlinerchassis.com/documents/KnowingYourChassisv2-20100324124504000000.pdf

Chuck

[RayChez1]

Yep! I would start with the compressor to see if it is putting out any air.

It would be very unusual for both air lift valves to go bad at the same time. But I did have one that stayed in the open position when my coach was new in the front and the air bags on the front would not inflate, but you could hear the leak right under the wheel well on the drivers side. I had the coach towed by Coach Net to a freight liner shop in SD and they replaced the valve. It was still under warranty. Never have had that problem again.

[RayChez1]

Let us know what the outcome was, so that others can learn from something like this.

03Heritagerider: I thought you had gotten rid of your Gulf Stream Coach?

[03heritagerider]

Sorry I didn't get back sooner.

Shortly after posting on this forum on Tuesday morning, I called the Freightliner hotline...those folks have helped me on several occasions.

They gave me the order in which I should look, and it didn't take long to identify the culprit.

First he told me how to identify the air dryer. He explained in detail where it was and what it looked like, and told me to send him a picture to verify (He specifically stated that Freightliner DOES NOT recommend customers crawl under their rig to do repairs). I sent the photo and he verified it.

He said, with the engine running, start with the heavier line going into the top of the dryer housing and disconnect it (this line comes from the compressor). If there was air coming out of the line, then the compressor was working. There was air coming out, so onto the next step.

Next he said to run my hand around the dryer housing, filter and the other line to feel for air escaping. When I ran my hand around the bottom of the filter and could feel the air coming out. I was able to twist off the filter using a rigged ratchet strap. Upon inspection, I found a crack near the bottom where the filter makes contact with the unit. It was small, but I hoped it was the cause. Once the issue was identified, it was a simple matter of getting the filter. No one locally had it in stock, but the nearby NAPA dealer said they could have it for me the next morning

Wednesday I picked it up, and bought a strap wrench to tighten it. It was the same process as changing an oil filter. Clean around the mounting threads and base, lubricate the "O"rings (2 of them) and screw it onto the mounting post and tighten (Manufacturer recommendation-hand tight).

I started her up and both the front and rear air gauges began to move and the bags began to inflate (neither happened previously). It took about two minutes and everything was at maximum pressure and I could hear the check valve spurt out the excess air. I turned it off and then checked the gauges every two hours, without starting, to see how much air was lost. After 4 hours it was only down about 15 pounds and was still 30 pounds above the 65 pound warning buzzer limit. This morning I checked again before starting and it was still around 75 pounds and it took about a minute to reach the 110 pound max level.

Afterward, I drove the rig for about 50 miles on city streets and highways with western Pennsylvania and northern West Virginia hills with no issue.

Thanks to all for the info, advice and concern.

RayChez1 - I was getting ready to pull the rig out Tuesday to take it to a consignment dealer when it wouldn't inflate. Fixed it yesterday and took it today...that's the 50 mile drive I made.

[RayChez1]

Thanks for the information. That kind if information will help all of us in case we come up with the same problem.

Are you going to give up RVing or just want to get another coach? Hate to see you get another brand because you have been a great forum member. Great advise every time. But since Gulf Stream is not manufacturing class A coaches anymore, I guess we all eventually will end up buying a different brand.

[03heritagerider]

Thanks Ray,

We're not sure what we want to do yet. First we have to see if the rig sells. Then we are either getting a toy hauler trailer or just a small cargo trailer for the bikes and rent condos wherever we go.