AC Vacuum pump failure - where do I buy one?

[Cinequip]

The little plastic vacuum pump that runs the dampers in the dash AC system runs continually, and won't shut off unless you tap it with a screw driver. Today, I unplugged the 12v power from the pump so I wouldn't have to keep beating on it. I know it's not a leak, since I can perform 2 or 3 dash mode HVAC mode changes before the vacuum is insufficient to continue. Good news is we just need AC, so I can drive around all day with the pump disconnected. This pump is attached to the steel wall directly in front of the steering wheel, but slightly to the left. It's on the Genset side, and you have to look up under the front face of the nose to see it.

So, anybody know where one might find a replacement? We will be in the Salt Lake City area next week.

I'm looking forward to the day when we don't have mechanical failures each day of driving....On the other hand I'm learning a lot about the coach!

[Gary Arnold]

Scott.

Was nice to meet Marcia and you in Glens Ferry.

Two weeks ago our pump would not shut off and like you I unplugged the power. Later I came up with the idea of lubricating the pump with silicone. I disconnected the input vacuum hose and while running squirted spray silicone in to the intake until I could see it coming out of the exhaust. I did not seam to help right away but after sitting for 24 hrs now works better than when new. My thinking is that some time must pass for the propellant to evaporate inside the pump.

[EngineerMike]

Scott- the VP was sold by Acme which is now out of business. Fortunately, the dash switch assembly, a Ford product, doesn't care whose vacuum it gets, and you can google 12V vacuum pump and follow the leads. There is one hit from TheDieselPage that suggests salvage yards for a VW or Mercedes pump; you could also try google for RV salvage and ask about vacuum pumps.

[Sammie]

Scott, you might try this company for AC parts for dash air units. This is the company that makes the AC units for Winnebago.

http://www.scsfrigette.com/hvac-syst...es-catalog.php

Sammie

[dgerstel]

The spects that were given to me by someone from Acme are: 15 inches turns off, 12 inches turns on and 10 inches minimum. Although I don't know the manufacture, the part number from them was 4570729.

[Cinequip]

As usual, many came to my rescue with solutions.

Gary, I lubed the pump as you suggested, but after two days, still wouldn't shut off.

I eventually found an exact replacement on a Ford parts site. Apparently, WRV switched pumps after ACME went out of business. They used pumps that Ford installs in all the big diesel pickups and vans. Cost is over $100 at a dealer, but Dan Richins in SLC came to my rescue with a deal at NAPA. Ford p/n is F81Z 2A451 BA

So, I'll replace the pump tomorrow along with a defective rocker switch for the door awning, and we'll be 98% again.

Thanks, everyone!

[takepride]

Scott:

Thanks for posting a photo with your information. It will help lots of people dial into the problem more quickly (likely for many years to come).