5 ton won't build air to trailer

[jgator]

i have a trailer hooked up to my 5 ton and it won't build air past 60 psi; builds good pressure when the trailer is disconnected....

anyone have similar issues with this???

 

[porkysplace]

What kind of 5 ton and trailer ?
Are the lines crossed ?

 

[Tow4]

Walk around the trailer and listen for air leaks.

 

[Greenbeast1]

The trailer is a 20 ton tilt trailer with ABS brake system. I don't think the lines are crossed, but I am not familiar with this type of truck. I had the trailer working with an international truck and it works fine. Any ideas what to look for?i just bought this truck from jgator. Everything is like new. There are no air leaks in the trailer. I checked for leaks around the truck and found none. The pressure drops when I open the air valves to supply the trailer.

 

[Greenbeast1]

M923a2

 

[ichudov]

Build up pressure in the truck. Turn engine off. Hook up the trailer. Supply trailer with air (open valves). Listen for leaks.

 

[Greenbeast1]

 

[Greenbeast1]

I tried that. The primary fell to 60. The secondary fell to 90. There was no air leak sound from the truck or trailer.

 

[ichudov]

That's normal, the trailer also has tanks, and the air found more volume for itself.

Now if you run the truck, does the pressure stay at 60?

Can you close the valves, re-pressurise the truck again, and supply the trailer again?

 

[Greenbeast1]

The trailer requires minimum of 100psi to free the parking axel. I changed the glad hands to quick connects. The moment I open the valves , the pressure falls to 60. It falls lower if the truck idles. Increased rpm to 1000 and the air pressure maxes out at 60 in both primary and secondary.

 

[Greenbeast1]

Yes, I closed the valves. The truck pressured back up, but it took several minutes.

 

[quickfarms]

The trailer requires minimum of 100psi to free the parking axel. I changed the glad hands to quick connects. The moment I open the valves , the pressure falls to 60. It falls lower if the truck idles. Increased rpm to 1000 and the air pressure maxes out at 60 in both primary and secondary.

If the trailer requires 100 psi to release the spring brakes then there is a problem. The spring brakes should release about 60 psi. The air compressor cut in pressure can be set as low as 85 psi.

 

[Greenbeast1]

I have had this trailer for 2 years. It has always required 100 to release the spring brake. My international truck airs up pretty quick and stays above 100 with no problem. The trailer has Haldex ABS brake system. I don't know if there is a setting that can be changed to lower the spring brake of the trailer.

 

[ichudov]

I have had this trailer for 2 years. It has always required 100 to release the spring brake. My international truck airs up pretty quick and stays above 100 with no problem. The trailer has Haldex ABS brake system. I don't know if there is a setting that can be changed to lower the spring brake of the trailer.

The pressure that would release spring brakes is determined by the brake chamber. I cannot see how you could even find a brake chamber with such funky release pressure. Sounds odd.

 

[Greenbeast1]

The pressure that would release spring brakes is determined by the brake chamber. I cannot see how you could even find a brake chamber with such funky release pressure. Sounds odd.

I looked up the Haldex ABS brake system. Also the Bendex ABS system, they both show the pressure to release and activate the parking brake axel to be between 90 and 120 psi. Maybe I am not explaining it right. Something might need to be adjusted or something is stuck. I just don't know where to start.

 

[Greenbeast1]

What kind of 5 ton and trailer ?
Are the lines crossed ?

I took a look at this possibility and discovered that the lines are reversed on the truck even though they. Put the red on the drivers side and yellow on the passenger side. They are positioned correct in the front oft he truck correct but the glad hands are also mis identified. Thanks to everyone that tried to help me solve this mystery. The truck was re manufactured in dec of 2012 so whoever hooked up the lines on the truck must have been sleeping that day!