Hello to all. The car is an 87 300SDL and when the temp wheel is set around 26C and I've got the EC button (economy i guess) for floor heat only, the air is coming out of mostly the defrost vents, some from the side vents and some for the floor vents. I suspect he vacuum pods are starting to go. How many of these pods are there on this car and are they easy to get to replace without major surgery?

Thanks!

First up: Do you have a Mityvac?

Yes. I've got one.

Second up:

Pull the carpeting and passenger kick panel from the right side.

Carefully remove the carpeted piece of cardboard that sits on the right side of the transmission tunnel.

Next to the CCU, to the right, you'll see a set of six electromechanical switchover valves in a vertical series. Unscrew the manifold as an assembly and pull it out a bit so you can get to the ports.

The vertical ports are the vacuum supply ports. You'll see that they all originate at one supply hose. Check the condition of the supply hose at each valve and be sure that they are not leaking.

The horizontal ports go to the pods.

Remove each hose from the horizontal port and connect it to a Mityvac (using an extension hose, of course). Pump up the Mityvac and see if the pod holds vacuum. Usually, it will hold with very little bleed, or it will fall instantly.

Report back with results. There are six switchover valves that go to six pods. #1 is on the bottom IIRC.

Thank you Brian! That will get me started. If it is a pod or two would it be prudent to replace them all or am I asking for trouble to go that route? Or just replace what's defective?

We have not even begun to get to the fun part............finding and replacing the pods. Once you do one or two of those..........you're not going to want to do them all..........

And, pray that the center vent pod holds vacuum. You'd rather stick needles in your eyes than try to replace it with the dash in place.

I think I'm going to practice pulling the dash out of the 1991 350SD in the junkyard this coming weekend. Just for grins, of course. The 87 Champagne center pods appear to be working fine. I might have a different pod issue.

__________________
daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
Cluster Needles Paint
New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more