vacuum leak
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Member
Joined: Sep 2011
Posts: 213
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From: Indiana
2002 S430
vacuum leak
I head problems with the closing assist system (like so many of you), only worked if the car was left alone for a while. After driving more than 5 minutes the vacuum was gone and I could hear the pump quite for a long time trying to restore the vacuum. Two service stations diagnosed I need a new pump, a third guy suggested it may just be a leak somewhere. So I checked all the nine connections on the pump plugging each, one at a time. This way I figured out that the leak must be at the rear seat head rest motor. I plugged the MKL connection leading to the headrest, now all the other functions work perfect, and the pump is silent when I drive. Now I want to get to the head rest motor to see if I can eliminate the leak or need a new motor (much-much cheaper than a new pump). Here I need the advice from a experienced guy: how?
From the trunk it is hopeless, the gas tank blocks the access, so the backs of the rear seats must be removed. The seats themselves are easy business. I do not want to damage anything, so I would appreciate some hints how to take it apart in a friendly way.
From the trunk it is hopeless, the gas tank blocks the access, so the backs of the rear seats must be removed. The seats themselves are easy business. I do not want to damage anything, so I would appreciate some hints how to take it apart in a friendly way.
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Joined: Dec 2008
Posts: 146
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From: VA USA
2000 S430 140k (07/11)
Lower the head restraints. Unscrew 3 bolts at the bottom of the seat back after removing the seat cushion. Disconnect connector for seat heater if there is one. Lift the whole seat back up and remove.
Thread Starter
Member
Joined: Sep 2011
Posts: 213
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From: Indiana
2002 S430
The pump is in the trunk behind the left hand side trunk lining panel. Remove it careful, you may have to undo a few fasteners in the back wall of the trunk. The pump is wrapped around with thick insulating foam. The top part of the foam is kept down tight by two metal wedges on the front and back side. The wedges can pried away a little by hand letting the top foam go loose. Careful, the foam tears easily. Under the foam you can see all nine lines connected to the pump by snap-on connectors. The four connections in the top row are coded as SK RAF HECK TD (the fifth is not connected), in the second row he five connections are FoR FoL BFT FT MKL (I wish I knew the meaning of these acronyms). I removed the lines and plugged the connectors one-by-one to see if there is any change. When I plugged MKL, the soft close became fully functional at all four doors and the trunk lid. The MKL line seemed to lead physically to the rear head rest area, so I checked all three elements and found no leak. Next I reconnected MKL and turned the lumbar switch to level 5 when I was driving, felt nothing, and when I parked and left the car, the closing assist was gone. Driving home I turned the switch back to 0, and the doors close fine ever since. I checked the air pouch behind the back cover panel of my seat, it looks OK, so next I’ll dive under the seat to check the element, and maybe the switch should better be changed as well. Good luck to you with your puzzle solving. I am interested to learn about your experience.
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Joined: Nov 2009
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From: ON, CA
2003 S430
I'll get back to you on thursday or Friday I'll because I've never experienced anything of your problem my only problem is the trunk !!! I disconnect the batter for 10 min an reconnect it the soft close works for the trunk I unlock an lock the car an bam it stops working ! I know it's really no big deal since I don't use the trunk much and it's been like that for a year but if I can fix it then why not
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Super Member
Joined: Jan 2008
Posts: 508
Likes: 1
From: california high desert
2003 S500, 03 C240, 03 E320, 03 tahoe
Great troubleshooting!
The pump is in the trunk behind the left hand side trunk lining panel. Remove it careful, you may have to undo a few fasteners in the back wall of the trunk. The pump is wrapped around with thick insulating foam. The top part of the foam is kept down tight by two metal wedges on the front and back side. The wedges can pried away a little by hand letting the top foam go loose. Careful, the foam tears easily. Under the foam you can see all nine lines connected to the pump by snap-on connectors. The four connections in the top row are coded as SK RAF HECK TD (the fifth is not connected), in the second row he five connections are FoR FoL BFT FT MKL (I wish I knew the meaning of these acronyms). I removed the lines and plugged the connectors one-by-one to see if there is any change. When I plugged MKL, the soft close became fully functional at all four doors and the trunk lid. The MKL line seemed to lead physically to the rear head rest area, so I checked all three elements and found no leak. Next I reconnected MKL and turned the lumbar switch to level 5 when I was driving, felt nothing, and when I parked and left the car, the closing assist was gone. Driving home I turned the switch back to 0, and the doors close fine ever since. I checked the air pouch behind the back cover panel of my seat, it looks OK, so next I’ll dive under the seat to check the element, and maybe the switch should better be changed as well. Good luck to you with your puzzle solving. I am interested to learn about your experience.
