Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 14, 2025 ...

Air noise

November 02, 2017, 01:17:41 pm

I have an air noise coming from passenger side of dash in my 89 U280.    "Psssss............Pssssss.........Psssss" every few seconds.  I've traced the sound- I think- to this device inside the little door below the passenger side window.  What is this?  The small air tubes don't want to stay on anymore so I put zip ties on them- not sure I have them back correct?  but the sound is still there.

Any help appreciated.

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Re: Air noise

Reply #1 – November 02, 2017, 01:20:45 pm

Vacuum pump and reservoir for dash HVAC control.

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Re: Air noise

Reply #2 – November 02, 2017, 01:23:15 pm

Wow- that was quick- Thank you!!!

Question then.  I don't use the dash air- doesn't work.  can I just disconnect this?  or is there something else I would affect?

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Re: Air noise

Reply #3 – November 02, 2017, 01:27:45 pm

Dan,

The vacuum is used to move the doors in the HVAC system-- directs air flow to windshield (default/no vacuum position).  With vacuum, you can also choose dash level or floor.  So, probably need it to direct heat as well.

Before abandoning it, see if you can locate the vacuum leak(s).

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Re: Air noise

Reply #4 – November 03, 2017, 04:18:56 am

"Before abandoning it, see if you can locate the vacuum leak(s)."


GOOD LUCK FINDING VACUUM LEAK !!!!

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Re: Air noise

Reply #5 – November 03, 2017, 02:46:28 pm

Just go buy a bunch of vacume hose and replace all of it. That stuff is cheap and it's all old.    You will still need it for heater control.

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Re: Air noise

Reply #6 – November 03, 2017, 07:45:50 pm

Be sure to check the vacuum canister, ours had been replaced by a P.O.

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Re: Air noise

Reply #7 – November 03, 2017, 07:46:47 pm

That is excellent advise Bob, my vacuum generator runs all the time. I ASSumed the valve was worn out, duh, there's a very good possibility that the hose going to the damper is bad or disconnected. Im half deaf so I can't hear vacuum leaks. Can't be more than 8 feet of hose total.

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Re: Air noise

Reply #8 – November 03, 2017, 10:46:47 pm

Cut short and reattached a lot of leaking vacuum hoses.

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