hvacdude

I just got a 2005 S55AMG and a few things didn't work, like the seat lumbar. I have the multi contour/ dynamic set up. So, here is the basics about the components , how the system works and what I learned.

#1 There is a pump in the left of the trunk, under the trunk liner. The pump makes positive air pressure. Not vacuum. Seats have nothing to do with the vacuum pump for the doors. Seems to be some confusion about that in a lot of the threads I've read thru.

#2 The pump will run for 20 or 30 seconds and shut down if there is a leak any where in the system.

#3 Each seat has a grey tube that feeds to the bottom fitting on the control module in located in the back of the seat. Remove the two screws in the bottom of the seat back. Pull the seat back down and towards you and you will see the control module and all the tubing. Pull off the bottom grey tube on the valve block and see if you have pressure. Turn the ignition key off then on to reset the pump. If you get air pressure you can then check the bladders for leaks. If there's no pressure, the pump or the lines up to the seat{'s} are bad. Lucky me, I had pressure.

#4 The bladders are wedged into the seats and held in by elastic straps. The bladders are wrapped in a felt like material. You can undo the straps and pull them out. Be gentle with them or they will rip.

#5 Slit the tube at the valve block fittings with a razor and pull the tubes off.
Be gentle, the fitting can be brittle and break.

#6 Stick the tube from the bladder in your mouth and blow them up. If they build up pressure they are good. If there is no resistance, the bladder is leaking. Also look for broken tubes.

#7 If you heat up the tube with a lighter, you can push the tube back on to the air fitting.

#8 If a bladder is bad, push a rubber vacuum tube cap on the valve block fitting for that bladder. Put some spit on it. The supply line and bolster bladders are 5/16ths. The shoulder and back bladders are 1/4 inch. You can get the tubing at a hard ware store. It is hard flexible tube like for a refrigerator ice maker water line.

#9 Start on the drivers seat. It gets the most use. All of my bladders were shot. After I capped off the fittings on the valve block then I checked the passenger seat and every thing worked on that seat. Because I had a leaky system both of my seats lumbar did not work.

#10 If you have bad bladders you can buy them on line. they are expensive to buy from the parts places. I made some make shift bladders that work good for next to nothing $$ wise. Now don't laugh; I used blue disposable nitrile gloves to make the bladders. I put 3 of them on my hand, one at a time. Then I took the triple glove off of my hand, careful to keep the finger tips pushed all the way up. I then took the tubing I mentioned {in step #8}
and stuck it in the glove about mid palm. Then I twisted the bottom of the glove tight around the tube and zip tied it to the tube, tight as I could. I used two zip ties then taped it up tight with electrical tape. I blew them up like a balloon and put my thumb over the line. They hold pressure ! I made 4 of them and stuffed them into the the seat in place of the bladders, hooked up the tube to the valve block, turned on the key and used the seat lumbar switches and they work great ! Cost me $5 for supplies.

#11 if the pulse button light flashes, the pump has shut down from leaking.
The massage mode will fill up the bladders for about 10 seconds, deflate for about 20 seconds, then pump up again. The massage goes for like 5 min then shuts off. At least mine does.

greglig

Hi, great post! I have a 07 W221 with the same problem and have not yet removed the drivers seat to strip it down.
Can you tell me where the failure points are on the original bladders?

Depending on where the damaged is I'm looking at this stuff:

https://www.tear-aid.com/

Problem is I'm in Europe and may have to get it from the States.

Cheers.

MikeKerr7

Awesome post- thanks for taking the time to write-up and share!

hvacdude

So, the glove thing worked just "okay" for the lower back, but not so good for the side bolsters. they bulged out towards the seat back.and weren't firm enough. So I decided to use small tractor tire inner tubes. I bought 3 10inch inner tubes at Menards mega hardware store. I also got some 7/32" vacuum line to connect to the inner tubes. I'll continue on from the original post.

#12 take out the schrader core from the inner tube. grease the filler on the tube. push the 7/32" vacuum hose as far as you can on to the filler neck of the tube, then push the plastic tube from the valve block into the other end of the vacuum tube. Use the 3rd port {from the bottom up} of the valve block. That is the low back part of the system. I capped off the center back port on the valve block {4th up from the bottom, red tube}.

#13 Remove the factory air bags that have the yellow and red tubes. Open up the inner tube so it looks like a big doughnut. Grease up the tube and your hands and slide it in where the original bags were. If your hands are greasy you can stick your right hand in between the seat and the white partition, push the tube thru with your left hand and pull it thru with your right. Try to get it in the center of the seat

#14 The side bolsters: Fold the inner tube in half. Hook up the air filler like I described in step #13. Grease up the tube and slide it in where the original air bladders were. The outer "arch" of the inner tube goes towards the front of the car. Then take some stiff card board and wedge it in front of the tube. This keeps the tube in place.

#14 the center lumbar control will inflate the the tube when you push the top portion of the center lumbar control. The tube will deflate when you push the bottom part of the center control. When you engage the pulse function, the tube will inflate and deflate for about 8 minutes. The + and - switch on the control will not do any thing.

Talk about firm lumbar ! the rubber inner tubes work way better than the original air bladders. For some reason my pump randomly quits. I may have a leak some where. I drove the car for 20min in the pulse setting and it worked the time. Then the pump locked out. My pump seems to come and go. I put soap bubbles on all my connections and they didn't bubble. After the car was shut off for a bit the functions came back. I may have to look for leaks near the pump. I would have took more pics, but my phone battery died. Sorry.

hvacdude

Greglig, the bladders split on the seems. They get brittle. The drivers side gets most use and all of mine on the drivers side failed accept the shoulders. I didnt think glue would work. You don't have to tear apart the seat. the bladders pull out from the back.

TBrasse

I have a new (used) pump, but I have bladder leaks. I thought all was lost and I'd have to rip the seat apart or take it to an upholstery shop. I'll be giving this a whirl.
Thanks!

hvacdude

Okay, so I have learned a lot about this seat system. A few of the things I said in the previous posts were not exactly accurate. It's important to know how some thing is supposed to work before you start messing with it. I was not using the seat controller properly, didn't understand it. Well now I do and so will everyone. the + and - on the round part of the control is a mode. The + is the inflate mode, the - is the deflate mode . the long switch with the arrows are for the lower bladder or the upper bladder. If you want to increase the pressure in the lower bladder first you push the + to put it in inflate mode then push the bottom arrow. that inflates the lower bladder. If you want t o decrease the firmness, push the - button to put it in deflate mode and push the bottom arrow and the lower bladder will deflate. I was wrong about how the switch worked in my step #14

I was also wrong about the pump. The pump makes pressure for the seats and it makes vacuum for the doors.
The pump run time seems to be based on time. I thought it may stop based on pressure or temperature {too hot} or maybe current draw shuts it down. I opened up the pump housing. it's got a motor and a circuit board. No switches that I could see. I'm pretty sure it's based on run time. If you fiddle with the seat control a lot, it will shut the pump down.

I thought I might have a weak pump, so I decided to boost the system by adding a tire inflating pump to the pressure side of the system. I just tee'd the discharge into the pressure line off the original pump. I'm not so sure I needed it, but it definitely works 100% better with the rubber tire tubes and the extra pump. The dynamic seat function is amazing. The lumbar and side work great. The seat is the most comfortable car seat I have ever sat in. I got supper charged seats to go with my super charged engine.

I Piggy backed my aux pump off the wires that feed the motor inside the original pumps housing.

I took my new {too me} 2005 S 55 AMG for it's first road trip. We had both seats set on dynamic, pulse massage, adjusted them just right. they worked great. after about two hours I noticed the pump was resting. Shutting the car off and turning it back on gets the pump going. I haven't tried this yet but I'm thinking since the vacuum system for the doors runs on the same pump, if I open a door it might restart the pump. I'm also starting to think the since my drivers door doesn't suck shut, it may be making that pump go into lock out. that may explain why the pump randomly shuts down. I will figure this thing out yet. So far what I've done, the inner tube bladders, work fantastic. The dynamic function is just great, and the seats are super firm.
Check out the pics:

ROG100

Thanks for the write up. I believe the pump you are working with controls the seats but also the soft close on the trunk. There is a separate pump for the doors soft close.

wallyp

No - There is one PSE (Pneumatic Service Equipment) pump for all of the pneumatic functions (separate Airmatic pump, of course). The pump is fully computer-controlled, with complex interactions. The computers monitor all functions.

If your driver's door doesn't soft-close, the most likely answer is that the door close actuator is leaking, and the computer has shut it off. If a function fails to complete within a specified time, the computer will shut that function off to avoid wearing out/burning out the pump.

You can reset the computer by pulling and reinserting the yellow 20-Amp fuse behind the floor light behind the right-rear passenger's heels. If the function still fails to complete within the specified time, the computer will again shut off that function.

hvacdude

Wally thanks for the info. On the pump there are two connections one makes positive pressure the other makes vacuum there are two reservoirs also.

compaddict

iTrader: (1)

Thanks for the write up!
Just how expensive are the replacement bags?
Links?

ibeforreal

Very good write up.

ls1_mast

thanks for the great guide i just did what u said and since the only available option of tubes i had is bicycles so i went with it for the dynamic seats and it was a success. it has been a year i'm trying to fix this with no luck untill i came across ur thread and i'm very glad that i did .