semi trailers

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Nov 10, 2009 | 11:16 AM

C-700

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From: Phoenix

semi trailers

Anyone ever hurd of or have a tailer using vacumm operated brakes or info on them?

Nov 10, 2009 | 12:51 PM

BPofMD

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From: Millersville, MD

You DO mean besides the BIG rigs, right? I do not believe there is such a small trailer. Too costly for one thing - compared to electric or hydraulic.

Nov 10, 2009 | 02:56 PM

senix

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From: Frederick, MD

never heard of it except for some military applications.

Nov 11, 2009 | 06:11 PM

99whiteford

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From: Barbourville Ky

Several of my customers around here have them on there gooseneck trailers.there is a vaucmn booster with a master cyliner mounted on the trailer.they have a belt drive vacumn pump located on there engine and have quick couplings located in their beds.they work great from what I have heard

Nov 12, 2009 | 03:25 PM

TexasRebel

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From: Stillwater, OK

why use vacuum and not compressed air?

vacuum has a very VERY limited pressure range... 0-1 atm (0-14.7psi)

if you put a belt drive vacuum pump on, why not just put a belt drive compressor on? It would even come in handy for other things... like air for tires and tools...

Jan 3, 2010 | 04:24 PM

bigredtruckmi

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From: Huntington Indiana

semi's and any vehicle with air brakes use compressed air running between 90-120PSI.

Jan 3, 2010 | 05:22 PM

C-700

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From: Phoenix

It is not what the truck uses but what the trailer uses for brakes. A lot of big trailers used vavuum brakes and not air pressure. We are talking the 30s and early 40s. I had never heard of such, until I got a truck with air brakes and two sets of air lines for the trailer. The two glad hands for the air pressure system and two vacuum lines I just could not understand. I have been collecting info on the vacuum brake trailers and am finding there were a lot of them. The truck I have is a 49 and equipped to pull trailers set up either way. Double duty. We also used less air pressure back then on air brake trucks. Any one that has any info please chime in.