940 station wagon,,,,,non turbo,,,when i have the heat set to blow thru the

dash vents it does fine until you go under a load and then starts blowing

out the dash vents. the check valve on the firewall seems to be working fine. any ideas?

Center vacuum motor blew a load.

If you are fixing it yourself, there is an ugly little shortcut that can have you done in 90 minutes instead of 8-10 hours.

If a shop fixes it, make sure they don't do the shortcut and bill you for the book job.

shadow,

thanks for your immediate response! where can i find out how to do the

"shortcut"?

apparently, you have had experience with this. the volvo repair shop

acted somewhat clueless about it.

Big Johnson:

What it comes down to is either removing the entire dashboard, airbags, electrical clusters, duct work, EVERYTHING, to replace a round, 4" dia. double-teated, push-pull vacuum motor that has undoubtedly torn its little isolator sock over the acutator rod.....

-OR-

Pulling down the knee bolster and hacking out a rear facing section of duct. If you don't have hands like Godzilla, you can squeeze in there and pop that sucker out, largely 'in situ'.

Then you have to repl the panel you hacked out and seal it up with some silicone. I KNOW.... this sounds Mickey Mouse, and it IS! But WTF Johnson?!?! it's only a duct! It only has to carry AIR.

I dunno, I did it first. Two years later, it works great. Since then, several others have tried it and Dick Reiss even made some nice photos of the job which are located in the archives. I don't have a link, but look in this general area: "Replacing the Vacuum Servo on 700/900 with ACC Double-Acting Servos".

You may need a trip to the chiropractor when you are done, but it ain't that bad.

I can't find the Epistle that I wrote on this. But Dick did a good job... so... Errrrr.... ummm.... 'Dick' meet 'Mr. Johnson'.

I am so sorry for that! Simply couldn't resist. Anywho...

oh yeah, there is a procedure for testing this thing before removal if you are quite convinced this is it. It can also be found in the archives or FAQ.

Now go check you private email for a message.

I did that job the hard way before I had a computer or even knew of the brickboard. Started it on a Friday late afternoon work to the wee hours of Saturday, thru Saturday and finished sometime late Sunday. The only thing besides cutting my hands to shreds (large hands I guess) was having only one new motor and finding out there were two inside the dash. You would think the parts guy would have said something. Luckily only the one was bad but I really wished I had the other motor to replace. I will never do that job again, but I think very body should do it at least once.

Dan Ray 94 960 169,000 miles

Oh Yeah Dan...... "You Ain't Lived Until....."

HA HA HA!!!

Don't sweat it. The double titted one is the only one of the three under there that really gives trouble. If you got it, then you got it. The others should be fine for a very long time.