Mercedes-Benz Forum banner

SL500 vacuum pump issues

1 reading
13K views 5 replies 5 participants last post by  Triple cranks  
#1 ·
Purchase an 06 SL500 back in December as-is and am trying to fix my last little hiccup with it which has to do with my doors locking but not unlocking. This has also caused me to break the fuel door off. A mechanic told me I should spend $1200 replacing the pump but the pump operates. Using various resources online I took it upon myself to unbolt the pump for the top to get to the vacuum pump for the door locks and take a look at it myself. The line plugged into the "SK" port is not connected to anything and when you press the unlock button air just blows out of the line into the trunk of the car. Common sense tells me this is probably why the doors are not unlocking, but I can't seem to find any resources indicating where this may need to be plugged in at. Can anyone shed some light on this??? I'm attaching a photo that shows this line (the very short hose) with nothing connected to it.
 

Attachments

#3 ·
I have had the pump in and out a few times in the last weeks si I am familiar with the setup

Althought the missing part looks like a filter it is probably a silencer for the air output from the vacuum pump

There is a cone shaped recess in the foam box for it to sit

Here is a link that shows the part:

https://mbworld.org/forums/sl-class-r230/583723-pse-pump-filter.html

The missing bit is probably not the cause of the locking problem

Good Luck
 
#6 ·
That filter/silencer in your link is not a factory part. It is a generic fuel filter generally used in small engine equipment. Although it is for fuel, it may be good enough and do a similar job. I buy them by the bag for about $1 each. If you notice the step on the inlet/outlet, that is for both 1/4" fuel line and 5/16" fuel line.
 
#4 ·
SL500 vacuum pump issues - line key

I recently had to chase down problems with my PSE pump. I came across this reference for the line codes that you might find useful:

Line key at pump:

IZV = interior central locking*system
HECK = Rear lid,*boot, trunk, lock
VL =left-hand*door lock
VR = right-hand*door lock
TD =*fuel*filler*cap
MKL = multi-contour backrest

Good Luck
Gary
 
G
#5 ·
Is there a diagram that shows how the air lines are run? Most of my lines are not holding vacuum. The pump appears to work when all inlets are capped. Once the lines are plugged back in, the 20A fuse blows indicating to me leaks in the air lines or leaks with the components the air line attach to.

I have a 2003 R230 SL500.