I traced a vacuum leak to a red line with a blue stripe on it. The line is attached to the vacuum line with the brake booster and goes through the fire wall with 3 other lines a black, brown and brown with blue stripe.
I have 15" of vacuum on the main line when I disconnect the red line with blue stripe and plug the line I get 20" of vacuum.
So what does the red/blue stripe line feed. I have a vacuum diagram on order still waiting. Any hope of getting more than 20" of vacuum? Thank You Ken

1983 300SD 235,000 miles

Red with blue stripe? EGR control? Probably not, that is white and goes to the tranny switch on the IP.

The climate control vac line is green. The brown is the source for the vacuum cutoff and the brown with blue stripe is the line to the cutoff from the ignition switch.
The black is a vent from the tranny control valve.

Does your AC blow out the vents or up the windshield? If it is up the windshield, no matter what you set it for, there is a leak under the dash, either a servo, the main control unit, or a broken or disconnected line.

I don't remember a red with blue stripe on the W126's I've seen.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

OK, I think it is a red line with green stripe. The stripe color is hard to see. The a/c blows good out of the vents. But when I try to swtich to heating I can't get hot air out of the dash vents and when I swith to defrost it won't move for the longest time if at all.
So I guess I need to look into the dash for a leak. Sounds like quite an adventure. Any tips on looking for vacuum leaks in the dash area? Thanks again, Ken