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Air brakes, what do I have?

joe--h

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Jul 22, 2009
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1,259
Location
Utah
This is an old UPS 40' trailer. Bought it to move and storage about 2001. Brakes worked then, moved it about 500 miles in 2003. Moved it again 800 miles in 2008. Has not moved since.
I want to use it one more time, about 800 miles again. Tires are definitely trash & brakes unknown. Probably rusted to the drums & no ideas on these air brake cylinders. I'm thinking I don't want to be those tracks going off the side of the highway when one of them fails, or not to worry?
How do I identify them & do they have to be exact replacements?
Or am I better off maybe to look for another trailer that's not been sitting forever?
8 tires & brakes or another trailer? This is only 40', I'd be happier with something longer.
If replacement trailer, where to look?
Thanks for your thoughts, Joe Hbk r 2.jpg front.jpg
 

92U 3406

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Jan 3, 2017
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Western Canuckistan
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Wrench Bender
Also, on those 3030 chambers DO NOT, under any circumstances, remove the v-band clamp on the piggyback portion (the clamp furthest from the pushrod end). That big spring in there has killed people. New chambers it is permanently crimped together. The other v-band clamp can be removed, just make sure you have the big spring caged properly.
 

Tenwheeler

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Dec 15, 2016
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870
Location
Georgia
Just measure the diameter of the chamber at the clamps. If in doubt bend a coat hanger in a c that fits and compare it to the new one. Probably a 30/30 short stroke as mentioned. There used to be some smaller ones, 24 or 28'? There were also different sizes for the park and service section on some. Yours a the same. The big chambers are probably as original equipment I would go with that diameter but they look the same in the picture. I have not seen any chambers similar to those on anything made since the 70's. The ones in your second picture are a direct replacement and still in production today.
 

Truck Shop

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Dec 7, 2015
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WWW.
Well all of it is antique, but it looks like it has auto slacks Merritor style. The rear air chambers i would update to a complete 3030 chamber. The front I would replace with 3030 piggybacks.
Because the front chambers are still the type with a bolted spring brake clamp those are real old. Those were outlawed 30 years ago. I know a fellow that has a steel plate in his forehead
from trying to rebuild one.
 

joe--h

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Joined
Jul 22, 2009
Messages
1,259
Location
Utah
Definitely an antique, UPS scrapped it long ago.
Looking on Ebay they are fairly cheap, China I suppose.
Is it possible to just replace the diaphram? Or not worth the hassle ?
 

Truck Shop

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Dec 7, 2015
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You could but on the safety side of things better to be safe. I would be careful removing the air hose fittings spray with some panther pi$$ real good while turning.
 

Tenwheeler

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Dec 15, 2016
Messages
870
Location
Georgia
They have other things that fail also. You also but yourself at risk of serious injury or death. Coil sprig in that thing about the size of your little finger. Takes 1800 psi to compress it.
 

Delmer

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Joined
Jan 3, 2013
Messages
8,864
Location
WI
Well, they dont look corroded. Apply air to park and service see if they leak. If you just don't trust em, air up park side and unbolt from anchor bracket. Swap out with a pair of 30/30s and yet good to go.

They look a lot better than most of what I see. You might want to look at that tire though:D If you're moving it just once more, break the brakes loose, check the air in the tires, carry a couple spares and tools and you'll be fine... until you aren't:D
 

funwithfuel

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Mar 7, 2017
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Will county Illinois
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Mechanic
Do those cans have 2 or 3 airlines going to each? Some buses use those bigguns with a 3rd line . You have to apply service to get park to release.
 
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catman13

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Aug 22, 2011
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oregon usa
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refrigeration engineer/excavation contractor
try craigslist , or trailer sales yard for a cheep one way storage trailer
 

joe--h

Senior Member
Joined
Jul 22, 2009
Messages
1,259
Location
Utah
Air in that tire is on my list Delmer, but it's on the inside so hard to see. Lot of mountains on the way to it's next home so ignore probably won't work. Guy that towed it down for me said he was close enough to ignore it when it went.
More research & been looking at CL for a longer newer one. Leave this one here for storage, it's a BONUS!!! Not something you'll have to tow away.
 

DMiller

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Feb 21, 2010
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Hermann, Missouri
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All are type 30, top are obsolete Rotochambers and piston type, lowers appear to be old Wagner units. IF you really must make this mess usable then charge the parking side, de-adjust the brakes, remove the band on the service side(closest to axle) then dump air and remove ALL of them. Roto units are/were crap, the other two have been on WAY too long and would not trust those either. By the looks of the service anchor side may as well buy complete units.
 
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