'06 Meridian, F/L chassis, vacuum pump issue?

[FIRE UP]

Gents,
A buddy of mine has an '06 Meridian 36' with the C-7 350HP CAT and a Freightliner chassis. Earlier today, he called me over for what he thinks is an issue with the vacuum pump in the front of the coach. It seems that that, that vacuum pump runs all the time. I put my hand on it while the coach was running and, that little pump was purring along and putting out a tad bit of vibration.

Now, that pump, has a hose on it that runs up to what I'm pretty sure is a small, vacuum storage container about the size of a soft ball. It's got a seam all the way around it. He said he removed that ball and tested it and drew quite a bit of vacuum on it so, he's pretty sure there's no leak there.

But, he cannot get his little vacuum tester to draw down a vacuum on the rest of the system, that leads from the out put side of that little vacuum ball. Should he be able to draw a sealed vacuum or, is there something that's kind-a open-ended like an A/C door or, or any other vacuum controlled component? thanks for your help here.
Scott

[BFlinn181]

The pump should draw a vacuum and it should hold until something (HVAC) calls for vacuum. The pump should also shut off when preset vacuum has developed. Check the hoses running to each vacuum motor on the HVAC system, you can pinch off a line and test vacuum in each branch to narrow down the search. If the vacuum is too low in the HVAC system, all air normally is defaulted to the defroster vents for safety.

[cbeierl]

Check out this thread: Vacuum Pump Failure

[Gary CA]

That little vacuum control can be purchased at a Ford dealer that has heavy duty truck parts, call ahead. To install all you have to be is skinny enough to place you body in a tight spot and have a long reach. The part cost me about $90 some 5 years ago.

[drczap]

We had similar symptoms with our 2005 Vectra while at high elevation (11,000 ft). Problem went away by itself when we dropped down to 5,000 ft. Cummins tech in Denver told us he has experienced this elevation issue repeatedly. Pump works fine now.

[Pelledan]

I have the '06 Journey 36G which is the Meridian's sister ship. I have the Cummins 300, but neither power nor propulsion is relevant to the problem. I had the exact same thing happen and unfortunately it took many dealer visits before it was resolved. Lift the front "hood" and you will see a small green hose that goes to the heater valve in the upper left area. That hose was redesigned (I think materially) by Winnebago a few years back to prevent cracking which is one of the sources that cause that pump to run all the time. The second culprit is the vacuum manifold which is on the back side of the environmental knob that you turn to control air flow direction such as floor, defrost etc, & A/C mode. The manifold itself is culprit #2. On the back of the manifold is a 4 or 5 vacuum line connector that snaps on the back of the manifold. Each one of those lines needs to be individually tested to hold a vacuum. If any one does not, the pump will run all the time. As far as my problem, I had the green hose and manifold replaced which did solve the issue for a year or so, but then the problem returned with similar, but not exactly the same symptoms. It turned out I had two of those manifold vacuum hoses had slight leaks caused by abrasion with something else under the dash. It's now been 2 years since the final repair with no further problems, so I'm pretty confident it's all good now.
Dan

[Sammie]

Hey Scott,
Here is a thread that may help you solve your buddies vaccumn leak problem.
http://www.irv2.com/forums/f101/vacu...ure-49296.html


Scott, send me a PM with your new address. I have some Cat goodies I will send you as I have bought a new coach and have no use for them anymore.

Sammie

[FIRE UP]

Originally Posted by Sammie

Hey Scott,
Here is a thread that may help you solve your buddies vaccumn leak problem.
http://www.irv2.com/forums/f101/vacu...ure-49296.html


Scott, send me a PM with your new address. I have some Cat goodies I will send you as I have bought a new coach and have no use for them anymore.

Sammie

Hey Sammie,
How is ya Pal? Hope all is well. I'll check that thread out and report back. We're presently in San Diego right now and, will be heading back to home port of Lake Havasu in the morning. I'll more than likely report back when we're back in the home base. Thanks.
Scott

[jerichorick]

Scott, it this pump on the firewall? I take it that he has capped each of the ports on the pump one at a time? The one that stops the pump when caped must be the one the leaking line is attached to.

[FIRE UP]

Originally Posted by jerichorick

Scott, it this pump on the firewall? I take it that he has capped each of the ports on the pump one at a time? The one that stops the pump when caped must be the one the leaking line is attached to.

Rick,
At last conversation with him, he thinks he's narrowed it down to the green line, from the pump or ball, I can't remember which, where it enters the heater control valve, has a leak there. I think he's cut the tip off and slid the line back into the heater control valve and I think he's good to go. I'll re-check with him to make sure so that, I can report and accurate fix. Thanks for the tips. Much appreciated.
Scott

[jerichorick]

Originally Posted by FIRE UP

Rick,
At last conversation with him, he thinks he's narrowed it down to the green line, from the pump or ball, I can't remember which, where it enters the heater control valve, has a leak there. I think he's cut the tip off and slid the line back into the heater control valve and I think he's good to go. I'll re-check with him to make sure so that, I can report and accurate fix. Thanks for the tips. Much appreciated.
Scott

Your welcome Scott. We all desire to give tips. It is really good when the tip is too.