HI ALL, Well I just bought a 1979 300SD at what I thought was a good deal $800.00. The body and inside are great. I just drove it home and noticed that the brake booster quit and the tranny would not shift into 4rth gear. It shifted very hard and would not shift at low rpms. The prev. owner said that the vacuum pump was bad. Would this cause these problems? I love the car and hope it is still a good deal. Also the car would not accelerate above 60 mph in 3rd. It has aturbo engine. 249955 miles.

 

Thanks for the help. Where do I get the manuel from? I don't know what MB's classic center is.

 

Also the engine will not shut off unless I cut it off at the engine itself.

 

Ok I unplugged the brake booster vacuum line from the vacuum pump. There was some suction and it increased when the motor rpms increased. Is it possible for the pump to not pump enough vacuum? Will a rebuild kit fix this? Does the vacuum control the transmission shifting? No matter how hard you press the pedal, the car will not shift until the rpms are at 4000. Any help would be appreciated.

 

Thanks for the info however mine does not have that on the top of the engine. There is a metal rod that goes down the passenger side of the tranny. I adjusted it and there was no shift difference. I did get the vacuum pump repaired and restored the engine shut-off, door locks, climate control and the trans did shift into 4rth at about 61 mph. When I slowed down to 54 it immediatly down shifted to 3rd again. I thought maybe the kick down under the accelerator was the problem so I unplugged it and still no change. Any help would greatly appreciated.

 

Ok someone out there has to know how to adjust the shift time on this car, I am barking from 1 to 2, It will only shift at about 25 mph to 2 and then it will not shift to 4th until about 61 mph, then it will down shift back to 3rdat 53 and stay there. When it is shifting, it don't skip 3rd I just forgot to put it in there. I fixed the vac pump and got all the other vacuum stuff going but the trans don't shift any different, fluid looks good and it has the correct amount. ANY HELP WOULD BE APPRECIATED.

 

Yep it's connected and I saw no vacuum lines hanging. I did notice today that if I press the brake just a little it will shift sooner. Would that imply a vacuum issue? Is there some kind of one way valve or something?