Tired of ACCII on my W116 - PeachParts Mercedes-Benz Forum

thorsen · #1 10-24-2010, 01:28 PM

I lost count, but I think this is the 4th time this year that I have to pull the dash out to fix something related to ACCII. Vacuum connectors have leaked, the hard plastic vacuum lines have cracked, vacuum elements have split, and now I have a high-pitched vacuum sucking sound coming from the upper dash. I even had to replace my servo with the UT upgrade when my servo locked up.

I am seriously considering replacing EVERYTHING this time. I'm thinking McMaster-Carr for the hard plastic lines and connectors. I am looking for a source of the rubber diaphragms inside the vacuum elements - does anyone know where I can buy just the diaphragms instead of the whole element?

If I could find a complete manual climate control setup I would seriously consider switching it in. I like the idea of ACC and I think it fits the character of an S-class but these vacuum leaks exhaust me.

Squiggle Dog · #2 10-24-2010, 03:49 PM

This is why I am ripping out the ACCII and replacing it with a complete Euro manual climate control. I have all of the parts. The electrical will be interesting. I might do a write-up on it.

thorsen · #3 10-24-2010, 04:23 PM

Where did you find the Euro manual controls?

Turned out to be a bad center vent actuator - it had a small pin hole in the diaphragm. The good thing is that I have taken the dash out so many times I can do it in about 15 minutes.

daw_two · #4 10-24-2010, 06:21 PM

I have a set of euro manual controls --- could be had cheaply --- might get you started.

I'm getting ready to purchase a 240D, automatic (slowest Mercedes on earth) because it has manual controls.

thorsen · #5 11-01-2010, 01:23 PM

So as a winter project, I am considering replacing the vacuum motors that control the flaps with something like this:
http://servocity.com/html/s9405_hi-torque_mg_bb.html

I would use something like this to control the electrical servos:
http://servocity.com/html/dual_servo_driver.html

I need to come up with a way to interface between the UT ACC upgrade and the servo driver - maybe something like vacuum switches or tapping right into the circuit board, or I might be able to work in a manual control somehow.

Are there any electrical gurus on this board? I would love to be able to remove the vacuum portion of the ACC system - the car was out of service for issues related to the ACC system more than any other problem I had.

audihenry · #6 11-01-2010, 07:45 PM

Have you tried upgrading it with that $700 kit? Might be worth the time/effort/money to just do it right once.

Squiggle Dog · #7 11-01-2010, 09:17 PM

Quote:

Originally Posted by thorsen

Where did you find the Euro manual controls

I stripped about 3 Euro W116s of the entire heater assemblies when they came into Pull-A-Part. I got the heater boxes, wiring harnesses, controls, faceplates, firewall valves, etc. I might pull the dashboard and start removing the ACCII parts this winter, but then again, I might just wait until spring.

thorsen · #8 11-02-2010, 08:08 AM

I did upgrade to the Unwired Tools ACCII upgrade. It's a nice kit but it does not address the issue of the vacuum servos that control the flaps.

Maybe it was just a bad year for me but I had more problems with the connectors/lines/servos this year than I want to count.

thorsen · #9 11-07-2010, 06:07 PM

After I spent the week researching how I could replace all the vacuum pods in the ACCII system and settling on a very good product to replace and control them, I decided to spend a few hours today and see if I could trouble shoot the system as it currently sits. Armed with the vacuum diagram and Mity-Vac, I narrowed it down to a loose connection on one of the factory 4-way tees. I sealed it up and the system now holds vacuum for 10 minutes after the car is turned off.

I decided to keep the vacuum system but invested in a smoke machine. The next time I have a vacuum problem that should make it much easier to track down.

bgiovan · #10 11-15-2010, 10:20 PM

I may fly you to Detroit to help me with my Euro conversion Squigg. Working on your care package this week.

Squiggle Dog · #11 11-15-2010, 10:55 PM

Quote:

Originally Posted by bgiovan

I may fly you to Detroit to help me with my Euro conversion Squigg. Working on your care package this week.

Thanks! Yeah, I might tackle the conversion this winter, not sure. I'm sure I will learn a lot in the process.

WANT '71 280SEL · #12 11-16-2010, 10:13 AM

I have the manual system in my w116 and it has its share of problems as well...seized heater levers...vacuum leaks (which also keep the A/C from working in the summer)...constant hissing sounds... Either way, vacuum systems in 35+ year old cars just aren't up to snuff anymore. Then again, I can only imagine the electrical nightmares we'd all face if they hadn't used vacuum...

Regards,

David

WANT '71 280SEL · #13 11-16-2010, 10:14 AM

Oh, and Thorsen, how is the job removing the dash on a w116? I have one of the few dashes that isn't cracked and would like to keep it that way...

Regards,

David

thorsen · #14 11-16-2010, 10:44 AM

I've done it so many times that I can do it in less than 30 minutes now. It's not a hard job at all. The only bolt that is difficult to get to is the one that sits horizontally in the middle of the dash. Once you remove the glovebox liner it's not bad at all.

Thanks for the counter-point on the manual system. I guess the grass isn't always greener.