Since the expansion valve and drier are fairly cheap I would start off with those as well. Expansion valve is less than $30 and the drier around $65. Just make sure to change all o-rings. You have to be careful when installing expansion valve. Make sure to put a lot of oil on o-rings and that it goes in straight to prevent pinching.
Another thing to check are the sensors. Your low pressure definitely works because it turned on the compressor when you added freon. However, the high pressure controls the aux fan and since your high pressure only reached 150 you really don't know if it's working. It might be safer to change it. I've seen many people bypass it (runs the fan all the time), but I prefer things to work the way they were designed to work.
I've notice that you never mentioned vacuuming. Did you guys vacuum the system for at least 30 minutes?
Are you still using r-12?

Vinamg

Vinamg,

We did vacuum the system for about 8 minutes before we charged and yes, we are still using the old R-12 freon. Mark suggested that we convert the system before we attempt any of the new repairs. Do you agree?

Pressure sensors? How would I test to see if they were bad or not? If so, what would they cost to replace and would I replace them before or after the dryer/receiver & the expansion block?

Thanks Vinamg!

Jeremy

Both sensors screw into the drier. I think they cost about$20-$30 each. Your low is probably working since the compressor engaged, but I have seen some of them leak next to the output wires. The sensors can only be tested when the system is working. To be on the safe side you should change both. The two sensors come with the o-rings. Then you simply screw them into the new drier and install the whole thing (need two o-rings for the two pipes).
Unless you have difficulties getting R-12 I don't recommend switching. I know that some people might disagree with me, but R-134 can never perform as well as R-12 in the old systems. This is especially noticeable in hot areas. What's the temperature like over there? BTW when you buy the expansion valve most of them are set for 134. If you decide to use R-12 your tech needs to adjust it.

Vinamg

Jeremy,
When replacing the high pressure switch put in the latest version and not the original green colored one as the temp for the fan to come on is too high. Use the red, which is a lower temperature, and there maybe a newer one than that available now. The sooner the fan comes on the better for the hot summers you have in Alabama.

For others interested:
The seat belt retractor gear in aluminum is availble from Autolux, Inc. in Dana Point, Ca. The phone # is 949-493-5578. They also make sunroof gears, 126 window lift sliders, seat adjustment handles for 115, 116, and 126, AC diaphragm replacement units, and 108, 109, 113 heater handle levers. Also they make shift gate covers for 230, 250, 280 SL, 280SE/S 300SEL, 350SL and some others.

Tobias MB
4 MBs

Tobias MB,

Thank you for the accurate information on the seatbelt extender gear! I called Autolux and they will ship the gear out tomorrow. The gear cost was $55 + $5 for priority shipping. Their new phone number is 949-574-0054 (he just moved.)

Are there any instructions available for how to do this myself?

Thanks and all the best!

Jeremy

Gilly & Vinamg,

Regarding the headrests...

I played with them this evening and each seems to have their own individual personality! The driver's headrest will not go all the way up. Like Vin suggested, I raised the headrest all of the way up and tried to push it down; it would not budge. I lowered the headrest via the control switch and although it did not lower the headrest, I heard the gear and motor turning inside the seat. I then pressed down on the headrest and it budged. What's got me is that the driver's headrest only moves 2-3 inches up.

The passenger headrest goes all the way up, about 4-5 inches. Again, it will not lower until I lower the switch and then I can press the headrest down.

So, do I need the new part Vin described as the "track with the small box, which is the lock and release mechanism for the headrest?"

Thanks so much for all of your help!

Jeremy

The test proves that your lock release mechanism is broken. You definitely need to buy the part.

Vinamg

10-4 on that. With that description, I agree it is the headrest "transmission" as they call it.......Gilly

Gilly and Vin,

Thanks for the confirmation! What part do I order? May I purchase that from the site shop here or should I search around? Lastly, is this something I can do myself (I'm not a technician but I follow directions well.)

Thanks again for all of your help!

Jeremy

You could probably handle it yourself. I am "neutral" on where you should buy it. I don't get paid for offering my advice, so I have no reason to recommend you buy from Fast Lane. (hint hint) Your local dealer is the one who's gonna bail you out if your car quits on you someday (hint hint) so maybe you should spend a little money with them. They'll probably even show you how to install it. On the other hand, Fast Lane does have this website just "teeming" with able bodied factory trained MB techs to offer assistance (Hey, I didn't know MB has a factory in Illinois!!!!).....Gilly

Gilly,

As I understand it, the site is run free of charge and the expert advice is too. Personally, I think the site here is simply awesome!

That being the fact, my loyalties lie here with mercedesshop.com! I went to the FastLane shop and could not find the headrest motor part that we are talking about. Further, I need to order the AC parts mentioned above and would like to get them in before this weekend so that we can begin repair.

Lastly, thanks again for a great site! I would love to talk to you or your team about getting a hold of this incredible forum software you are running....it's the best I've seen ever!

Jeremy

Jeremy: Fair enough. The part you need is usually referred to as the headrest transmission, also sometimes the headrest drive. the motor is elsewhere in the seat, the transmission is driven by a cable that comes from the motor. if you can get the backrest rear cover taken off, and have the new part at hand, I'm sure you could figure out how to do it......Gilly

Jeremy,
Curious to know if you got the water/air leak fixed and the seat belt retractor mechanism working as it should? Did you get the gear OK and does it look OK to you. When installing it be careful of the position of the microswitches and to return them to the same place. Operate the retractors by opening and closing the door a few times. If you ever open the passenger door and close it then return later to drive the car, the pass. seat belt will operate with no one there!
It knows the door was opened, even overnight

Good luck,
TobiasMB
4 MBs