82 MB 300 SD
I am getting 18" of vacuum at the top port at idle and 15" to the transmission.
at the side port the one beside the adjuster I am getting 0" at idle and also at high revs. Can someone tell me what should I be getting there. Do I have a bad vacuum valve ?

Thanks in advance !

The side port is the vent. You will always get zero at this port. It's normal.

When you open the rack, does the 15" drop steadily toward 0"? If so, the VCV is working properly.

I recently adjusted the VCV on the SD to reduce vacuum. I've got it down to 8" at idle. The shifts were a bit soft at the original setting of 12". They have firmed up at 8" and I'm going to drive it for awhile to see if it's OK, or whether an adjustment to the modulator is required.

If you are having shifting problems, go to post #5 here:http://www.peachparts.com/shopforum/showthread.php?t=134563&highlight=transmission It is a condensed version of the transmission adjustments/vacuum checks I found at MBZ.org. It worked like a charm.

Also, another hint, I found it was easier to just replace the flex fittings for little more than $10 and eliminate 20 year old rubber as a leak source.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )

1984 300d Turbo 136k
Use A Hand Vacuum Tester From ************************ $65.00
10 Psi Pressure Top Output And 30 In Out Front Take Off Top Vcv
Ip Hose Engine Off And Connect Hand Vac Pump 10-15 In Vac For Transmission , More Linkage To Full Power Should Be Zero Engine Off And Check Line Direct To Trans Will Hold Vacuum 20 + In

Lucky,

Don't hook up the tri-connector wrong. You could ruin the trans if full vacuum is on the trans all the time. Don't ask me how I know.

One of the leads has a pin hole in it and that lead has to be connected to the vacuum supply.

P E H