Vacum pump 500SL

[BRABUS124]

I'm in the rabbit hole on a diagnostik thing with a 500SL

It got ortopædic seats and the vacum ou p I got working for the central locking now. It had an internal hose leak in the pump. And it's leak tight in open and closing the central locking now. But when ever I turn on the ignition the pump starts anotjer feature or function for as far as I know the ortopædic seats Cushings. But there's a leak in the seats and for now I don't have time to look into that so I blocked the 2 output for this feature on the pump it self. To avoid it seeing a leak and drive itself to its dead.

But the problem is it's still doing the pump thing like a small pump or vacum run for 1 se. Every 4 sec.

So my idea were to locate that ou that tells the pump it's on ignition to avoid it going into this mode where its trying to a tivate the ortopædic seat function.

So the question is 2

1. witch of these vacum hoses are for the ortopædic seats? I know all the yellow ones are the central locking but there's 3 grayes and one clear as well as a yellow with blue stripe on it. Witch are what and did they also use vacum for the HVAC for something?

2. What are the pin numbers funktion diagram electrical?

 

[kubasz]

This pump has ports that are constantly monitored for pressure and vacuum as soon as you turn the key to pos2. P+ is for pressure and P- is for vacuum.
P+ (gray line) is only used for ortophedic seats so if you turn the adjusting wheels on both seats to 0, pump should stay shut on P+ circiut.
P- (transparent line) is used for AC control assist and is connected to a MVA (129 800 14 78) valve which is known to crack and leak vacuum and should be replaced from time to time to prelong pumps life.
If you close pumps nozzles with your fingers and the pump still engages from time to time, it most likely has an internal leak in P+ or P- check valves. Thats easy to remedy by replacing red orings that seal off the check valves.

 

[BRABUS124]

This pump has ports that are constantly monitored for pressure and vacuum as soon as you turn the key to pos2. P+ is for pressure and P- is for vacuum.
P+ (gray line) is only used for ortophedic seats so if you turn the adjusting wheels on both seats to 0, pump should stay shut on P+ circiut.
P- (transparent line) is used for AC control assist and is connected to a MVA (129 800 14 78) valve which is known to crack and leak vacuum and should be replaced from time to time to prelong pumps life.
If you close pumps nozzles with your fingers and the pump still engages from time to time, it most likely has an internal leak in P+ or P- check valves. Thats easy to remedy by replacing red orings that seal off the check valves.

Great info. Yes I used the red plugs to close the leaking clear hose off. And the 3 gray hoses as well as one of the seat Cushing were acturly leaking. The the pump still pumps 1 sek and stops 5 sec then pump 1 sec again like that. But I think I will go with that for now

 

[BRABUS124]