# Vacuum Pump on Freightliner chassis



## sesspool

I have a 2000 Tradewinds on a Freightliner XC chassis. My dash heat and air only goes thru the defrost outlets(no matter where the selector switch is set). I want to make sure the vacuum pump is working but don't know where it is. Has anyone in this forum had this experience? Please don't tell me to follow the vacuum line.  :clown: 
Thanks,
Jerry


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## Guest

RE: Vacuum Pump on Freightliner chassis

well first off welcome to the forums ,,, and one other thing ,,, does u'r hvac unit have automatic climate controls ,,, if so that is another ball of wax to get into ,,, but going with u'r first post ,,, i hate say it ,, but the vacuum line will only go to the vac storage can ,, or ball ,,, when did this all happen ???? and was it all at once ???? but to answer u'r ??? What engine do u have in u'r rv ??? that will help to steer u in the right direction ,,, and i am sure others will step in and maybe help out ,,,  :approve:  :approve:  :approve:


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## Triple E

RE: Vacuum Pump on Freightliner chassis

Look on the fire wall, driver side, next to the window washer fluid tank.  Good Luck!!


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## sesspool

RE: Vacuum Pump on Freightliner chassis

Thank you for the reply. You were right on with the location, the vacuum pump doesn't seem to be coming on. I haven't checked for voltage yet,(it's kind of hard to get at because of the generator)I looked for a fuse but haven't located it yet. I haven't figured out yet what turns it on. The controls look like they are all vacuum lines(no wires). I found a diagram online(Evans tempcon) but it just shows the vacuum circuitry. 
Thanks for your help,
Jerry


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## Triple E

RE: Vacuum Pump on Freightliner chassis

Sorry, my help ends here.  I just spent about an hour trying to trace the vacuum pmp wire.  It disappears into the fire wall.  Hope I don't have a problems.  What a can of worms.   

Good luck.


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## sesspool

Re: Vacuum Pump on Freightliner chassis

Thanks for the help Triple E.
That was very nice of you to look for the source. I checked the voltage at the pump lugs with the engine running and the htr on, There was nothing there. Youre right about the "can of worms". It looks like they use enough wire and tubing to go around the coach twice and then ball up the surplus and stuff it under the dash. Every time I try to get at anything I'm afraid I'll knock something loose. If I don't find it maybe a dealer or freightliner can help me.

Thanks again,
Jerry


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## Triple E

Re: Vacuum Pump on Freightliner chassis

My pump turns on the instant I turn the key on.  If you can, pull the vacuum line off at the pump or the vacuum ball.  This way the pump cannot build up a vacuum and will run continuous.  But if you are not getting any voltage this will not help.  If you are getting voltage and the pmp is not running than the pump is bad.

Let me know how things are going.  We are all here to help each other out.


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## kidswithfire

Re: Vacuum Pump on Freightliner chassis

I have a similar problem with my 98 Country Coach Intrigue.  I have a Gast vaccum pump (MOA-V111-JH)... apparently it runs about $225 plus shipping.  I was scheduled to take to Tempcon repair center (Camping World of Longmont) but will try the steps you mentioned here.  

Couldn't I disconnect the air line from the pump instead of the tank-ball?  Wouldn't that cause the pump to continue to run?

Thanks


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## Triple E

Re: Vacuum Pump on Freightliner chassis

Yes, either place will work.  Yes, your pump should run continuously with the vacuum line off.  Put your finger over the port and the pump should shut off.

$225.00 is the cheapest I found also.  Good luck.


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## kidswithfire

Re: Vacuum Pump on Freightliner chassis

What's your opinion on rebuilding the pump?  I'm fairly courageous...


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## Triple E

Re: Vacuum Pump on Freightliner chassis

I assume you have power to the pump.  So, why not.  If you can find the parts go for it.  Let us all know what happens.


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## lhyzer

RE: Vacuum Pump on Freightliner chassis

Give the manufacturer of your coach a call. They installed the system. 
They should be able to tell you what fuse panel the fuse is located
in or where the fuse is located. With no power to the pump there
either has to be a blown fuse or bad connection. Lets hope its a
fuse.
Good luck on your search.


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