You beat me to it except the I was going to say that the spring brake valve exhausts the air from the spring brake chambers not from the tanks.

The tanks may very well bleed down and that explains why some trailers take a few minutes to charge and release the spring brakes and others are ready to go as soon as you push in the brake valves.

I see that we are getting this all sorted out.

Mad Fatboy

 

I think we're both on the same page here. See the red highlighted area from my post.

 

I was going to say exactly that but when I refreshed I saw that you already had.
Guess that I'm just too slow today.

I'd say the this has about run it's course. Now if the other guys could just undersand it.

Mad Fatboy

 

how about this to simplify things?? although it's probably no longer necessary to hook up your air lines before backing all the way under, it also wont hurt anything to do it.. The best advice given on this thread is to do it the SAME WAY every time

 

Agreed.

Having a routine, and double checking everything will prevent trailers being dropped with the landing gear still up, torn off airlines and light cords, and landing gear wrecked due to forgetting to crank it up after hooking.

 

Mad Fatboy[/quote]

landing gear wrecked due to forgetting to crank it up after hooking.[/quote]

I did that ops: Not a word was said... Lesson learned

Important There are trailers out there that dump air bags when the red button is pulled !

I found this out as the tire guys where jacking up my drive axles for new tires, I thought I'll dynamite my trailer to keep the guys safe, so my unit can't roll away...

Well, as the airbags went down they pushed the tractor forward causing the jacks to tilt almost to the point where the tractor almost hit the ground....

 

:lol: :lol: Okay, guys!! I understand it!! I just like to hear you "explain" it!! Besides.... I'm trying to help you boost your post count! Especially YOU Fatboy!! You really need to jump in more. You've got some good stuff to tell about Trucking B.C.!!! :lol:

I'll tell ya ONE thing..... I sure wouldn't have wanted to be around with all these guys pushing trailers across the lot trying to "hook" 'em!! Although, it must have been funny (if it weren't so dangerous!!) :shock:

Okay... so we're all agreed!! UNLESS you pull a trailer older than Methusela, there's no need to hook airlines FIRST!! :wink:

And to think, this all started because somebody said he'd never been shown how to couple! :lol:

Now... one last thing:

Fredog said don't dump your suspension to go under a trailer, cuz you might ruin the bags or something. Since I DID suggest doing that when necessary (someone dropped a trailer with the gear just barely touching the ground,) and I HAVE had to do this at times.... can he or one of you other old farts explain what the danger is?? (don't take offense to that.... I consider myself and old fart, too! :wink: )

I don't want to tear up any equipment. But, my trainer showed me to do this when needed, and I can't see any harm, tho I CAN say I don't like having to DO it! Seems like alot of extra work for the bags to lift the trailer that way.

So.... just explain the danger to me (you don't have to use little words,) and I promise not to argue about it! :lol:

 

Looks like one of the other drivers went thoroughly into how you couple to a trailer so I'll spare you any further explanations.

1) Just wanted to give you some advice on making certain that the trailer isn't too high for you to "hook to the fifth wheel". It isn't a pretty picture when the kingpin gets in front of the fifth wheel. This happens when the trailer is too high for the fifth wheel to latch. When I started in freight the trailers were always too high for me because I had "low pro tires". Those are tires that are 3" or so lower than the usual tires on the drives. I always had to dolly down the trailer to get under it since all other drivers had higher tires.

I also dollied up when I dropped a trailer so that people wouldn't slam their fifth wheel into the front of the trailer when they came to get the trailer I had dropped. Other drivers told me they wouldn't have done that because it is each driver's responsibility to G.O.A.L. before hooking to a trailer. I did it anyway because I thought it was a courteous thing to do. Most drivers that are new have now idea that there are "low pro tires." I was repeatly told that my truck had been an auto hauler truck by any experienced driver that came into contact with me.

I only hauled freight two months and went into truck hauling [piggybacks and booms]. Therefore, I had never dropped the suspension [airbags] to get under a trailer since I was always too low. We were bobtailing and hauling empty trailers prior to hauling piggybacks and booms [truck dragged backwards-you see the tow trucks booming bobtails often]. I bobtailed or hauled trailers to yards in New England and then bobtailed across the border to drop off the trucks in Canada.

Consequently, I never had to drop the suspension [airbags] in my long two month freight career. One day I was at the Utility Yard getting a trailer with another driver. He proceeded to tell me to drop the airbags to ascertain that I could get under the trailer. He was spotting for me, so I thought, I dropped the airbags and tried to "hook to the trailer". Thought I had hooked to it because I did the tug test and it seemd to be hooked. I was going to pull away, and decided to get out and look. Apparently, unbeknownst to me Mark had walked away and wasn't spotting for me.

Low and behold I had the kingpin in front of the fifth wheel. Thankfully, there was a yard dog there that day that raised the trailer so I could hook to it properly. I was one Lucky Lady because it was a Sunday and I still can't believe a yard dog was there.

HENCE, ALWAYS G.O.A.L. Drivers will tell you to do the tug test only. That is definitely not the answer as you can see from what I said above. I did the tug test and it appeared to be hooked. It would have been a very expensive adventure to drop a brand spanking new trailer in the Utility yard. Most drivers I know don't G.O.A.L. prior to departure. That's a huge mistake.

Recently, I tried 5 times to hook to a trailer. Another driver was there and he had the same problem. I don't know what they did to the trailers at that particular shipper but it isn't common to take so long to get the fifth wheel to latch. I didn't have the time or inclination to figure out what the issue was, I just left after finally hooking to the trailer.

2) Another thing always make certain you've disconnected the air lines and electrical cord prior to dropping a trailer. I have actually pulled away and been fortunate enough that the pigtail cords were forgiving and broke lose without any damage. 8) :roll:

 

Okay, I think I've figured this out (with the help of Sizzle and a few others!) Why are trailers not ALWAYS at the perfect level??

One of our LOCAL drivers, who pick up our trailers and deliver the load on the East Coast, once saw me cranking the handle an extra few turns (like I said.... 3 turns ABOVE the hiss of your airbags releasing their pressure.) He THANKED me, and said many OTR drivers (with lower profile tires) don't realize that his OLDER rig had higher tires, and needed a bit more room to get under our trailers!

But, these SAME drivers, drop our empty trailers at the shipper.... and maybe THEY then "crank 'em up too high" for US!! :roll:

This is why I carry the 4/4's!! My trailers are usually TOO high or too low for me! I either need lumber, or need to dump my bags!

Since the yard dogs never TOUCH the dolleys.... this must be the reason!

Main thing is this.... ALWAYS back up until the frame (rear tires) are under the platform and then GOAL!!!! This way you can SEE if your 5th wheel is too HIGH or too LOW!

If the trailer is too LOW..... try cranking DOWN the dolleys (UP the trailer) using the LOW gears of the dolley handle! You can't do it with it in HIGH gear!

Same thing if it is too HIGH.... USE THE LOW GEAR on the dolley handle!

If this doesn't work, you'll EITHER need the lumber to climb UP..... or you'll have to drop the suspension! IF YOU DO.... don't try to lock the pin this way! Lower the suspension ONLY until you can get under the front of the trailer. BEFORE contacting the pin.... RAISE the suspension, make SURE the tandem brakes are SET, and THEN back up until it HOOKS!

There IS a simpler way to do this! With your suspension UP, take out your measuring tape (you DO have one, don't you?) and measure the heighth of your "FLATTENED" 5th wheel! Then, before hooking to any trailer, measure the heighth to the platform! A couple inches too LOW for the platform is okay, but even ONE inch too HIGH will not allow a good "hook."

I never really THOUGHT about the "profile" of the tires (even though it was mentioned by my local driver.) But, this should answer the question of why some trailers are too high or too low, unless someone is doing the 10 crank thingie!! :roll:

 

I thought I FIRED this guy!!! :lol: