Jump to content

Air brakes locking on trailer


dover

Recommended Posts

Good evening everyone,

Its been a while since i've been on the site. I have an early 70's hobbs 40' flatbed that I picked up for $600 over a year ago. It had 6 of the 8 tires in 50% or better condition so I figured why not. When I hooked it to the truck a while back and charged the tank the brakes would lock up. I figured it was a relay valve leaking internally to the service side. It is a single tank with no spring brakes. I was able to get it home by leaving the trailer circiut uncharged and hoping the friendly NHP trooper that stopped me for a flat spot on the trailer didn't decide to crawl under the trailer. It worked as I only got a ticket for the bad tire. I ran new lines from the front to the tank and bought a new valve. I put the new valve on last night and now it's not charging the tank when I put the air to it from the cab. When I pull the Johnson bar it charges the tank and locks the brakes. I have service hooked to service and emergency to emergency. What am I missing? I know its not in the truck because it works fine with the other two trailers.

Thanks

Ben

1962 B733 L cab

Link to comment
Share on other sites

  • 5 weeks later...

Switch the glad hands around, sounds like they are backwards.

This could be right. looking at the front of the trailer, the standard is red on right and blue on left but every once in a while you can find them swapped on old trailers.

You could also have the same problem I experienced just the other day on a trailer. It had been sitting awhile and something had built a nest inside the service glad hand. Truck started rolling fine but when I hit the brakes, the trailer brakes locked and wouldn't release. The nest had allowed air to go to the brakes but wouldn't let the air release when I let off the brakes. Took the line off the transport valve back at the trailer axles, blew air through the line, and the nest came flying out.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...