Air leak- any help?

while the engine is running and you are observing the air leak, turn the fan on manual, if the air leak disappears it's the fan hub, you have a newer style horton fan hub called a drivemaster?????? they can leak internally while the engine is running and you will never hear it. they have 3 different places they can leak from internally, look for a slight greasie residue around the edge of the hub where the aluminum and steel pully come together, should be some grease on the edge of the blades also

if so it's the hub, rebuild it with a rebuild kit from a company called gold top, this is a better than horton's by a mile

 

I don't think it is the brake chambers. Said it doesn't matter if the knobs are in or out. Usually when a brake chamber goes bad, it will do one of 2 things. Leak externally, or cause the exhaust port on the relay valve to blow air like there is no tomorrow. A bad quick release valve will also cause the exhaust port to blow on the relay valve, if the QRV has a signal line to the relay valve.


This link should help troubleshoot. I'm having a bigger problem than you are. The truck in question, the air compressor kicks back in less than 10 seconds after it shuts off. Haven't had a chance to work on it since someone else sent me this link. Hope it helps-

http://www.todaystrucking.com/images/BendixCompressor%20TroubleshootBW1971.pdf

Could as simple as the check valve on the air dryer on the line going to the wet tank. It's not what my problem is though. somewhere else. My valve is good, as is the governor.

 

O K;
Who wins the "I correctly diagnosed the problem" prize this round, and how many $$$$$$$ is it?

 

What a great helpful group we have here!

 

thank u your all too kind i accept all responsibilities for solving this problem, i will have a pepsi thank u shaken not stired

 

Not yet. Haven't had a chance to look at it yet. Been busy in the W9, and the Mack with the problem has been moving grain. That CH has almost 1 million miles on the clock, so it could be anything. The pressure drop is internal somewhere. All of the external leaks have been fixed.

It isn't the fan clutch. It has the bi-metal spring thermal clutch like what you'd see on a car or pickup truck.