My door locks stopped working so I started by checking the vac pump. The motor runs but there is no vacumn or pressure. I'm guessing there is a bad diaphragm. Can these be repaired?
Does anyone have a pump they want to sell?[/align]This is on a 1983 300SD[/align][/align]

 

Do you have access to vacuum pump gauge, like Mitac? If you do you can check out vacuum door locks problem real quick.

1) Your brake is OK? If pump is dead then you brake is questable. May be very heavy to stop the car.

2) Measure vacuum near the brake booster pump. It should be good and goes up when you rev the engine.

3) Remove carpet in driver's door floor and peel over the black plaster cover. You should see 2 T. ( may be more, cannot remember )

4) Green/yellow unlocks door, Red/Yellow locks.

5) Remove the T and hook up the gauge to green/yellow. Pull vacuum and door will unlock. Red line will lock. If it does not then one of the actuator down the line is broken.

6) Divide and consquer and you should be able to find out which door/truck/gas cap actuator is leaking.

7)Check the'check valve' which is next to the brake booster pump, also driver door vacuum switch.

8) Get a 2nd hand vacuum pump from a junk yard or a re-built one.

Good luck.

83 300D, 87 300sdl

 

Thanks boblo_home but this is a 300SD so it uses an electric vacuum/pressure pump that is mounted next to the spare tire and is completly seperate from the engine mounted vac pump. I have checked all other parts of the system and they are all good but the pump is not working the way it should.

I was hoping that some one was parting out a car and had a pump they would sell.