Cottrell CX09 trailer lifting issues

Discussion in 'Car Hauler and Auto Carrier Trucking Forum' started by Duck75, Jan 20, 2023.

  1. Duck75

    Duck75 Bobtail Member

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    Mar 19, 2019
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    Hi folks, new in this forum
    I have car carrier truck and trailer,trailer is CX09 2013 year, since I bought that I have issues to raise up my trailer. As soon I hit the suspension rise button my truck is raising suspension but trailer that time lowering suspension , when I turn off button for raise up truck go down to normal height and trailer raising to normal height too.
    If I push the button for lowering suspension truck height go down but trailer stays at normal position.
    Does anyone have any idea what can be issues of that? May be someone of you have air suspension diagram?
    Thanks
     
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  3. Hammer166

    Hammer166 Crusty Information Officer

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    2 completely separate things here.

    The first problem, trailer dropping when overlift engaged, is one of two things. Either the linkage for the overlift height control valve is broken, or the pilot valve is bad. Seems to me we just had this discussion with someone else a few months back, but I don't have time to search right now. You might scroll back through the threads, or search pilot valve. I think I even did a schematic, but not positive I did.

    The 2nd thing is normal. Trailers, if they have a dump system at all, normally have a separate control valve to dump the trailer at the valve bank. I've never seen one tied to the tractor dump valve, although you could easily enough run another airline back to the trailer to do so. Generally, when you need to dump the trailer, it's much handier to do from the valves and not have to walk up to the truck to do so.
     
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  4. Hammer166

    Hammer166 Crusty Information Officer

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    So I found the schematic, but it was for using a pilot valve to allow a shifter with different logic to replace an unavailable replacement, so no real help.

    The pilot is an air-controlled selector which is used to determine which height control valve sends air to the bags. If it's bad, you'll be able to find it spewing air when the overlift is engaged.
     
    Tall Mike Thanks this.
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