Need help changing out air line(s) on coach

[Chef Guy]

Originally Posted by Snokid

Both tanks held pressure. Should be real easy to hear 100psi leaking somewhere.

Snokid,

No, you misunderstood me....the rear tank holds no pressure, that is why the brakes are locked up. Front tank will pressurize, as long as you disconnect the rear air lines from it and plug them up....leak is somewhere leading from the primary/front tank to the rear/secondary tank....gobsmacked!

[Biljol]

So if you disconnect the lines from the rear tank and plug where they connect to the rear tank air the rear tank up does the rear tank hold air?

I am sorry but trying to figure out have you ever gotten the rear tank to hold air.

[Chef Guy]

To the best of my failing memory, I did test the rear tank and she checked out okay....just not when I connected the secondary to the primary,....which suggests a line going from the primary to the secondary. I will check it again tomorrow by itself as I removed it and she's laying on the driveway under the coach now.

[Biljol]

Ok cool.

What I am trying to do is split what’s powered by the rear tank and what’s powered by the front tank into 2 systems that would let us verify that the leak is the linking lines.

[Snokid]

Originally Posted by Chef Guy

Snokid,

No, you misunderstood me....the rear tank holds no pressure, that is why the brakes are locked up. Front tank will pressurize, as long as you disconnect the rear air lines from it and plug them up....leak is somewhere leading from the primary/front tank to the rear/secondary tank....gobsmacked!

If that's the case plug the lines where they go into the rear tank then charge the system with a compressor.
I'm hoping it's something easier than running new lines!

As I was typing that and proof reading it...

If the rear tank is what charges up the brakes and you have tested it but are loosing air still could be a blown pancake.

If you fill just the rear tank will the brakes release?

[Chef Guy]

After numerous hours under the coach I found the air leaks. I will be posting images soon as I fish the remaining air lines out from above/behind the plastic one piece covering inside the bay compartments. Rat chewing on a major scale...just as I expected and the 3rd vehicle of mine that has undergone massive damage to rodents since Christmas. Unlike the other 2 vehicles, insurance will not cover rodent damage.

I have found 2 airlines chewed so far with 6 more to check...they ran a lot of airlines through large plastic thin walled conduit above the storage bay.

Stay tuned for rat chewed air line hose pics...

[Mile Marker 42]

Originally Posted by Chef Guy

After numerous hours under the coach I found the air leaks. I will be posting images soon as I fish the remaining air lines out from above/behind the plastic one piece covering inside the bay compartments. Rat chewing on a major scale...just as I expected and the 3rd vehicle of mine that has undergone massive damage to rodents since Christmas. Unlike the other 2 vehicles, insurance will not cover rodent damage.

I have found 2 airlines chewed so far with 6 more to check...they ran a lot of airlines through large plastic thin walled conduit above the storage bay.

Stay tuned for rat chewed air line hose pics...

Depending on the severity, you can repair with these DOT fittings and DOT approved airline. I just bought 25ft of DOT 1/4 inch airline for $13 right here.

[twinboat]

Originally Posted by Snokid

Coming from driving big trucks sometimes the air brake pancakes would let go that would result in a large air leak.



Bob

They would only leak if stepping on the brake or holding in the parking brake knob.

No air goes to the air chambers ( pancake ? ) if the vehicle is parked.

[twinboat]

There are 3 tanks.

The wet tank #1, feeds both the primary and secondary tanks thru a double check valve.
The rear tank will be a doube tank, with the wet section and the primary section. The double check should be on that double tank.

Study the air system to help figure out the routing.

[Snokid]

Originally Posted by twinboat

They would only leak if stepping on the brake or holding in the parking brake knob.

No air goes to the air chambers ( pancake ? ) if the vehicle is parked.

I agree.

A pancake is a rubber diaphragm inside the brake chamber that holds the brake off till air is released and the spring then applies the brake.

Think of it this way when you pull the brake release/parking brake that is releasing all the air from the system so there needs to be a way for pressure to be applied to the brakes that is a spring.

On the chamber there will be 2 air lines 1 is the supply which releases the parking brake the other is the service which is where you get brakes when stepping on the brake peddle.

Inside the chamber there are 2 pancakes (A rubber diaphragm that looks like a pancake)

[vito.a]

I would use the old lines to pull the new lines through the conduit.