Air Brake Question

[topo]

you will hook up both lines . the constant air line will fill the tank and may say supply on the glad hand the other should say service this is the one that gets air when you push the brake and makes the brakes work .

 

[Scrounger]

That trailer appears to be a pre-1976 trailer. It also appears to have single as apposed to double can brake chambers. Therefore it doesn’t have automatic spring brakes.
It may have automatic brakes similar to the older 127’s, 129’s and the newer 105’s. They work by using the air in the trailer air tank(s) to apply the brakes in the event of a loss of air pressure on the emergency supply.
To tow that trailer there are a couple of options.
If everything is there and working, beside the hitch and chains connect the emergency (red) glad hand to the glad hand on the right side of the vehicle. The service (yellow or Blue) to the drivers side. Open both valves and check for air leaks. After the air tank(s) on the trailer are charged the trailer should roll freely.
If the brakes lock up, could be several things, starting with a trailer relay valve, shut off the air supply and drain the air tank(s). Brakes should release.
If you haven’t used or tested the service (yellow or blue) circuit on your vehicle I would tow it without brakes. Sometimes the air doesn’t release all the way after applying the brakes and the trailer brakes will stay locked or drag. The trailer is lite enough that there shouldn’t be a problem towing without the brakes.

 

[jaxsof]

The NSN identifies as a 1967, and I can not find a single manual for it. Some info says it also carried a wire reel. And 26' long

 

[Unforgiven]

Thanks for the info. I think you are correct in that it was used to carry large spools of electrical wire. And we all know copper gets heavy in a hurry.

 

[Unforgiven]

Update

The bolster trailer is home. It's smaller than I expected.

Yes, I just said that a trailer capable of hauling 14 tons is smaller than I expected.

Anyway, it did NOT have spring brakes keeping it locked. The forklift guy pulled it around like a little red wagon. We hooked it up and off I went.

I didn't bother hooking up the air brakes since it was empty. Technically I should have. But the truck didn't seem to mind it too much. It trailered nicely. The truck barely grunted going forward. It was only while stopping that the unbraked trailer was noticeable. I used surface streets and rarely got into 5th gear.

It did have dual air connections. It's a shame that I'll probably remove the axles. It really did trailer nicely.

But I have to extend the frame to accommodate the M36 bed. And I want to do a Spicergear Hydromax upgrade to the truck in the future. That darned air buzzer annoys me every time I start up. So the plan is to put a Deuce bogie under it with electric-over-hydraulic brakes.

Here are some pics so you can visualize the size of it compared to the M36 & the M105



It backed up really nicely into the driveway. It was much easier than the M105 was. I'm not sure if that's because of the tandem axles, the slightly longer tongue, or the lack of brakes. The M105's surge brakes are locked on the passenger side. I think the shoes are stuck to the drum. I haven't bothered to jack it up & free the brakes yet. That's next month's project.

Now I have to decide if I want to try to register the bolster trailer as is (meaning $60 more & a probably a month's wait for the SF97 from GL) or if I want to simply wait until my Big-Dumb-Camping-Trailer is complete and register it as homemade.