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    Guest Message by DevFuse
     

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    Front Mounted Air Lines For Towing



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    7 replies to this topic

    #1 OFFLINE   ThaddeusW

    ThaddeusW

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    Posted 04 February 2006 - 09:56 PM

    Ok I have seen a few trucks that have front mounted air hook ups for towing. The idea is that the tow truck can hook air lines to the truck in tow and be able to actuate the brakes on the towed vehicle like a trailer. Sounds interesting but I cant seem to find any diagrams on this setup.

    My idea is that you could plumb the supply line to the wet tank to charge the system using some type of special valve that also releases the spring brakes (something like the spring brake valve on trailers). Then the service line could activate a valve that bypasses and mimics the foot treadle. For a tractor you would also have to figure out a way to bypass the trailer supply valve or manually charge the trailer after you charged the tractor in tow.

    Any ideas?
    -Thad
    What America needs is less bull and more Bulldog!

    #2 OFFLINE   David

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    Posted 04 February 2006 - 10:35 PM

    If the wrecker is plumbed like a tractor, you can run the red line to the wet tank. When you release the trailer parking brake on the wrecker it will pressurize the entire system of the towed vehicle. Then you can release the parking brakes of the towed vehicle. The blue line from the wrecker can run to the service brakes of the towed vehicle and be applied from the wrecker when in motion.

    #3 OFFLINE   convoyduel

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    Posted 05 February 2006 - 01:18 AM

    When a wrecker tows a tractor trailer, the wrecker's trailer air lines are only used if the truck being towed has a trailer. In that case, the wrecker's air lines are run back to the trailer. You never hook the wrecker's air lines to a towed tractor's air system.

    The treadle valve on a tractor is the gateway for air applied to the service brakes. To access the service brakes, you would have to split off from the lines from the treadle to the brakes. Tractors with dual air brake systems would require an even more elaborate setup.

    It's somewhat of a moot point, as a towed tractor should only have 1 axle on the ground anyway. An empty tractor in-tow will be easily handled by the wrecker's brakes. If you also have a trailer, the wrecker and trailer's brakes will do what you need.

    #4 OFFLINE   ThaddeusW

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    Posted 05 February 2006 - 01:35 AM

    When a wrecker tows a tractor trailer, the wrecker's trailer air lines are only used if the truck being towed has a trailer. In that case, the wrecker's air lines are run back to the trailer. You never hook the wrecker's air lines to a towed tractor's air system.

    The treadle valve on a tractor is the gateway for air applied to the service brakes. To access the service brakes, you would have to split off from the lines from the treadle to the brakes. Tractors with dual air brake systems would require an even more elaborate setup.

    It's somewhat of a moot point, as a towed tractor should only have 1 axle on the ground anyway. An empty tractor in-tow will be easily handled by the wrecker's brakes. If you also have a trailer, the wrecker and trailer's brakes will do what you need.


    I more or less wanted to know how the setup works. I have seen many freightliner fl 60's and 70' for the NYC DEP Have those front air connections for towing. Also the old military trucks (dunno bout newer) had the front air lines for towing.
    -Thad
    What America needs is less bull and more Bulldog!

    #5 OFFLINE   Lmackattack

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    Posted 05 February 2006 - 09:01 AM

    you know you have a crap truck when the mfg puts air lines up front knowing its goin to br towed by a wrecker alot LOL!!!!

    #6 OFFLINE   ThaddeusW

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    Posted 07 February 2006 - 01:49 PM

    I just got a reply from Bendix with a very nice PDF attachment. It shows you a nice diagram, notes, part descriptions, and part numbers! The hookup lets you treat the entire towed vheicle like a trailer including releasing the brakes from the tow truck.

    [attachment=588:attachment]
    -Thad
    What America needs is less bull and more Bulldog!

    #7 OFFLINE   fuzzy buzzard

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    Posted 12 February 2006 - 12:41 PM

    Mercy, mercy! You have hit a nerve in old fuzzy buzzard! I realize this is kinda out in left field based on your original message but I got a song to sing here. These damn truck builders should be forced to install tow air connections on all air brake trucks so the draggin' wagon drivers have a fast way to hook up brakes on the towed unit. Sure its easy to air up the system - just pull the compressor discharge line and hook in your red line BUT do this on the side of the road with every 4 wheeler dusting the ass of your pants and half of the truck drivers (who are on cell phones) tap mirrors just above your head. Now we got the system aired up (your whites are hanging out the seat of your pants and most of that mirror glass is now in your socks) and can release the spring brakes. Now we got to pull a line off the tredle valve to hook up the service line so we can apply brakes to stop this overloaded mess when the fool in the far left lane crosses in front of everybody and cuts you off to get to his exit ramp. So here we go again - mirror glass down the shirt neck again, there goes the seat of the undies this time, damn driver knocks the plastic nut covers off the steer tire you just jumped over top of and the stupid engineer has figured out a way to postion the tredle valve lines so a snake couldn't get to them!!!!!!!!!
    Since we now design trucks that the dealer shops can't even fix, wouldn't it make sense to put air connection points on trucks so we can safetly pull them back to the factory (or junk yard as necessary)
    Amen!!!! Case you don't go to church, thats the end of the sermon
    Rev. Fuzzy Buzzard signing off!!

    #8 OFFLINE   ThaddeusW

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    Posted 12 February 2006 - 01:06 PM

    Mercy, mercy! You have hit a nerve in old fuzzy buzzard! I realize this is kinda out in left field based on your original message but I got a song to sing here. These damn truck builders should be forced to install tow air connections on all air brake trucks so the draggin' wagon drivers have a fast way to hook up brakes on the towed unit. Sure its easy to air up the system - just pull the compressor discharge line and hook in your red line BUT do this on the side of the road with every 4 wheeler dusting the ass of your pants and half of the truck drivers (who are on cell phones) tap mirrors just above your head. Now we got the system aired up (your whites are hanging out the seat of your pants and most of that mirror glass is now in your socks) and can release the spring brakes. Now we got to pull a line off the tredle valve to hook up the service line so we can apply brakes to stop this overloaded mess when the fool in the far left lane crosses in front of everybody and cuts you off to get to his exit ramp. So here we go again - mirror glass down the shirt neck again, there goes the seat of the undies this time, damn driver knocks the plastic nut covers off the steer tire you just jumped over top of and the stupid engineer has figured out a way to postion the tredle valve lines so a snake couldn't get to them!!!!!!!!!
    Since we now design trucks that the dealer shops can't even fix, wouldn't it make sense to put air connection points on trucks so we can safetly pull them back to the factory (or junk yard as necessary)
    Amen!!!! Case you don't go to church, thats the end of the sermon
    Rev. Fuzzy Buzzard signing off!!



    See now thats why I looked into it. Who wants to mess around with the air system to try and safely get the truck down the road. Hook, air lines, brake lights and your good to go.

    you know you have a crap truck when the mfg puts air lines up front knowing its goin to br towed by a wrecker alot LOL!!!!


    Hey Trent, no truck is perfect, even our beloved Macks. Making the towmans life easy is a big plus. Besides you get home faster that way.
    -Thad
    What America needs is less bull and more Bulldog!




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