Golfhobo, I to am considered "New school", but many of the infamous BBR's. Ive only seen a couple of these style spring trailers. Check out the link and quote from wikipedia.

http://en.wikipedia.org/wiki/Air_brake_(road_vehicle)

From wikipedia:

 

I over quoted the wikipedia link: I only need this much:

 

Next time you're near a trailer take a look at the brake chambers. There may be a holder on the side with a screw, nut and washer on it.
The nut is 3/4" and the other end has a "T". The "T" end fits in the end of the brake chamber and turns 90 degrees to engage the plate. Then by tightening the nut the spring brake will be released.
It can be a lot of work but sometimes it's needed to move a disabled trailer or truck.

Not all the brakes will have springs sometimes and you can apply brakes to those wheels.

SeaLand had some of the rattiest equipment back in the late 70's and two of us drivers almost got run over when another driver pushed a 35' reefer across 2 rows of parked trailers and into a trailer that we had been standing in front of.
That seemed to be standard operating proceedure there and I hated the place. And yes, that jet jocky had the gear up, hoses on and out of there in less than 1 minute.

Also hooking and charging the air to one of these trailers would set the brakes again. As long as there was air in the trailers tanks the parking brakes would be set. But all these trailer tanks leaked down and when they did... no brakes.

Mad Fatboy
Yes I am old and drove a lot of junk!!!

 

Sorry, Drew.... but I'm not "buying it!"

Okay, NOW I am! :lol: I SHOULD have checked your link the first time instead of just going by what you quoted. It was actually a pretty accurate article UNTIL you got to that one section. What seems to have happened there is exactly what I mentioned. Someone edited the original discussion, and changed the context of the discussion in that section.

Wikipedia is not a reliable source! It can be modified, changed, and even started by ANYONE, whether they know what they are talking about or NOT! Unless someone calls them on it, it will stand. But, it is NOT a "researched" encyclopedia like say Encyclopedia Britannica.

The quote you posted confuses the issue because it jumps, without missing a beat, from that of the OLD "parking brake" system, back to a discussion of modern day trailer emergency brakes.

ALL "air brake systems" use a holding tank for the air, which is resupplied by the tractor air compressor. While these tanks are full of air, the air can be released to RESTRICT the brakes. When you pull the red valve, it depletes all the air in the lines AND in the tanks! Therefore, with no air available to restrict them, the SPRINGS cause the brake shoes to CLAMP down on the drums, stopping the truck or trailer.

I really don't know much about "dollies" as I don't pull pups. In fact, I didn't even study that part of the CDL manual. But, I will if necessary! However, I can see why they might NOT have brakes AT ALL! They are just a conveyance! To put brakes on a dolly, would be to invite an accident, as they are not PERMANENTLY attached to the trailer!

This makes absolutely NO SENSE! (UNLESS you realize - which I didn't - that they are referring to a PARKING brake system... NOT the EMERGENCY brakes. ) This is saying that AIR is what APPLIES the brakes, and if lost, there will be no brakes. Yet, we ALL know that doing the pump down test is designed to EXPRESS the air from the holding tanks, to see that, once depleted, the EMERGENCY brakes will engage! It is the LOSS OF AIR in the emergency line, that will "dynamite" the brakes of a trailer!

It is precisely a minor leak in the air lines (or a catastrophic failure) that we are to be afraid of! And the reason for the ALARM that sounds if the air PRESSURE gets below 60 PSI! NOT because this would indicate a LOSS of braking power, but because it reflects a loss of CONTROL over the braking system, which then will LOCK UP and possibly cause an accident!

The exact error made by my instructor, and his "answer grid" on my final test, was that he said that SPRINGS held the brakes at bay I KNEW what answer they "wanted," but I refused to answer incorrectly! I pressed my case.... and I WON! However, that is a different issue than what we are discussing here.

My SCORE was not changed to reflect my proper standing in the class, but I don't care! When it comes to safety, and understanding my equipment, I WILL NOT be led astray by those who don't understand!

Whoever EDITED that explanation to Wikipedia confused the issue by combining explanations of two separate brake systems into one paragraph or context.

He probably voted for BUSH!! :lol:

Now, if there was some system BEFORE Air Brakes, used on trailers, that I am not aware of, I'd REALLY like to know.... even tho it is probably irrelevant to today's trucking. In fact, I'm quite sure there WAS! It is not RELEVANT to me or to most truckers entering the business today.... but it might be interesting to know about..... IF someone can give me a truthful, accurate explanation of it!


the Wikipedia author was referring to some ancient system of a PARKING brake that worked the opposite of the air brake system we have today, and the one who EDITED it, further confused the issue by posting THIS (that you found superflous:

This is EXACTLY what will happen with the AIR BRAKE system! So, which is he talking about? An "older" system that worked the opposite of today's air brake system? Or the current system which this quote supports?

After reading the article, I now realize that two different authors were discussing two different systems under the same section.
Again, I say that Wikipedia is a USER modified database! USERS can be wrong! I understand the Air Brake system. And I NOW understand what this author is saying! But, they should not have been combined as they were!

If trailers of old operated exactly the opposite, then I can understand the posts about pushing them across a lot while "hooking." And I can certainly understand why someone decided this was a BAD idea, and changed it to the exact opposite!

Obviously, they DID use a different type of PARKING brake, as opposed to the trailers of today, that basically combine the EMERGENCY brake system with (or AS) the parking brake!

I should have just deleted this whole post, but I decided just to clear up my own confusion for all to see! :lol:

I should have KNOWN better than to NOT check the source to get the proper CONTEXT!

 

I know the errors that wikipedia may contain, but they are refereing to "older" trailers.

I dont have first hand experience with pulling that old of a trailer, however, I did witness another driver try and hook one. He seemed to be to lazy to attach the airlines before hooking the fifth, and he basically got a slow running start at the trailer and hit it fast enough to get under it and get it hooked before it rolled to far back. It did roll about half a trailer length before it caught the fifth. Fortunatly there was a "curb" a ways behind the trailer that would of stopped it if he failed in his attempted rolling "Hook".

 

Great Discussing and Info everyone!....Thank for the read!

 

some pf us have pulled those old trailers and know that the info from wikipedia is true. I doubt if there are any of those trailers still on the road. even though spring brakes werent required in the 70's most trailers had them. we have a 1953 tanker and it has them

 

Yes it is!!! I nschool we were taught to get the frame under the trailer, hook up air lines, check height of trailer, THEN back on under the trailer. I too ask why. I was also told about the OLD trailers and their braking system. :roll: I can't believe that wasn't out-dated with the invention of the wheel.


As far as dropping trailers: As a driver that drops and hooks 9 to 10 times a night I have to say that if you have air bags then crank the landing gear to about 1/2 inch for loaded trailers and 1 to 2 inches for empty trailers. EVERYONE cad get under them and crank them ( the landing gear ) up MUCH easier.

 

plus if your truck picks the trailer up, it will latch for sure. I worked for Shaffer for a while and in their orientation, they said unhook, crank the legs down and when they touch the ground, turn them 10 more times.. that's just plain bad advice!!


you know something we failed to mention,, NEVER back under a trailer with your air bags deflated, you will ruin them

 

Please reread my last edited post. I don't want to confuse anyone. However, I left it in here for JUST the reason you mention. I thought someone might get some good info from it.

Sorry, if I originally confused anyone. I SHOULD HAVE CHECKED THE LINK!! :lol: