1970 lowboy brake conversion

[Jizzo17]

Hello everyone, 

I have purchased a new to me equipment trailer which only has service brakes on the rear axle. It came with two axles from another trailer with ~100k miles on them. They have the service and park break chambers. I would like to add the r12 and r14 valves to the trailer and plumb them up correctly with the anti compounding valve. 
The trailer has two air tanks along the frame rails. One is fed from the service side and the other is fed from the supply side. But they both feed into sides of the only r12(?) valve. Which may be normal for that old of a trailer but it has me puzzled on how I can connect it all together.

So if anyone has a tank off a trailer that has those valves already mounted I would be interested in purchasing it. Or someplace that might have one. That way I can just bypass the old tanks and lines to just run new ones. 

[mrsmackpaul]

I would think any business that sells trailer and truck parts would have a good selection of tanks on the shelf 

Most low loader trailers dont have enough room for tanks in the area around the axles and the like

 

They always look like they have bucket loads of room but when on full oscillation the axles cans tend to move a lot more than people think 

 

Paul

[Geoff Weeks]

Heavy equipment trailers were exempt from the spring brake requirement and may be still are.  You need to plumb it correctly with an SR-5 valve not just with a relay valve.

Look at Bendix's air brake manual for the correct plumbing or leave as is a carry some chalk blocks. 

Edited 3 hours ago by Geoff Weeks

[Jizzo17]

Thanks for the help. I have a few places I could call around to for what I’d need. They are just an hour or so away from me.

 

I think I could swap the 30/30 cans to just single 30s. But im not sure which would be easier/more cost effective to do. It may be one of those six in one hand, half a dozen in the other scenarios. 

Edited 3 hours ago by Jizzo17

[Geoff Weeks]

Coupla things, screw clamps on rubber air lines are not permitted. No way "one is fed from service the other from supply". You've got to get what you have legal before trying to add spring brakes. Without seeing the whole air system, I can't tell what is buggered up and what if anything is correct.

What I can see from that one picture will get you shut down in a heartbeat. You've got kinked copper line. 

I would correct the  defects that will get you shut down. I towed many trailers without spring brakes (I was a heavy hauler) over the years. Once the system is correct, you can see if there is enough room to add what is needed for spring brakes.

Also need to correct what is wrong with the RH S cam bracket, the push rod is not inline with the slack adjuster. It looks like something with the slack adjuster bushing isn't right, preventing the can as push rod from being properly in line.

everytime I look I see more wrong, right chamber fully extended, left chamber fully retracted, what the heck is going on there? Stuck or air to one chamber only? 

Edited 2 hours ago by Geoff Weeks
updates

[Jizzo17]

I really don’t know what the previous owner had going on with the brakes. I’m going to cut those axles out and weld new ones in. And will also put new air lines in. This is really just a trailer to haul my trackhoe and dozer between farms. But I want to make it as safe as possible. 
 

I just thought it may be easier to buy one of those tanks with the valves attached and mound it inside the frame. 
I’ve added a pic of what I’m referring to. 

[Geoff Weeks]

1st, it looks like they are 12" brakes so new axles will also need to be "low boy" axles, 2nd that is a lot of brackety to weld in for no gain.

What is wrong with the current axle?  

Axle and brake are two different things. 

That may be an SR-5 but I can't tell from the picture.

What size tires does it have on it now?