1980 300SD - shutdown problem with CCU Set to Off/Lo/High

[jbrasile]

Chris,

Makes sense regarding the fresh air function since your a/c is out. One thing, from what I understand #43 is there only to pull the fresh air door open 20% during max a/c, the white/blue pod is what actually opens and closes the flap, you might want to play with it a little so you get 100% outside air all the time. Both these actuators are accessible with the dash in place anyway so I wouldn't worry too much about getting them repaired early in the project.

Yes, R-134 is working very well here in Sao Paulo now that I have all my actuators working properly, I measured center vent temperature the other day inside my mechanic's workshop and got -3C with and infrared thermometer so I think the conversion was a success. My car is modified to run the aux fan together with the compressor in order to help condenser efficiency and keep the engine cool even on a 100 degree day in heavy traffic.

The check for leaks you should probably use a reputable a/c shop, doing it at home involves purchasing the gauges and perhaps some liquid nitrogen as well, but it's no rocket science either... given a choice, I would stick with R-12 after making sure your system is 100% leak free, it just works better for these cars.

Pod 41 I believe is located at the lower part of the a/c box, the manual indicates it can be replaced with the dash installed and just says to remove the center ducts under the dash, you should be able to see it behind the struts at the center of the dash, the flaps for the floor air vents go up and down so if you work them you should be able to find which side the pod is connected too. Sorry I couldn't be more specific.

Tks,

Joe

[ckamila]

Though my pace is slow i continue to make progress and run into a new roadblocks along the way.



Today i was finally able to open both center & defrost pods while not removing the dash.     But having a problem separating dual chamber defrost pod middle section where we have 2 plastic cupped pieces with a diaphragm sandwiched between. Appears plastic sections should just snap apart but did not after applying light pressure but did produce a snap though nothing visibly changed/broken. Unable to pull apart either. Small rod connects bottom end with control arm to middle section with rod passing through center of spring, center of bottom cup and diaphragm and then attaching to center of second cup.

Bottom section of dual chamber defrost pod still attached under dash.


Small rod in center passing trough lower cup

You can just see 1 of the 2 torn section of diaphragm above - the whole reason i am here!

Center of upper cup is where rod ends


Anyone out there with info on dissecting a dual pod?

Joe, is this way you suggested purchase new for parts?


Chris

[jbrasile]

Hi Chris,

Yes, if you get a new dual action defrost pod all you have to do is transfer the internals to the old one, with the repair kit it is a lot more complicated as you are finding out. I actually experimented with my old internals and I think you have to cut the diaphragm out of its base and glue the new one, does that make sense?

Tks,

Joe

[ckamila]

Joe - I don't see a way to glue new diaphragm in place as it needs to go between plastic cups. The ID of the outer cup is smaller than the OD of the new (or old) diaphragm so won't be able to slip over the top of bottom cup either. Instructions seem vague for this part of the procedure. After many readings of instructions looks like slicing off the entire bottom section is needed, turning the cup into a 1.25" long tube. I don't want to revisit this area again! I can use any unused diaphragms on my 123 where i have center and floor vent vacuum leak issues.

Going this far to fix the leaks i will add a new dual pod to my list:
(1) Dual action pod
(6) 3-way connectors for the central locking (4) and (3) misc others connections
(4) 4-way connectors for under dash
(4) feet of black rubber tubing to replace connections between devices and vacuum lines
(3) check valves.

Thanks,
Chris

[ckamila]

This thread is going/gone off topic. In the interest of getting assistance  and also to the reader, i have started a new topic.

I will provide link to the new topic when established. http://forum.w116.org/mechanicals/acc-overhaul-heater-box-evaporator-removal/


Thanks for your help,

chris

[ckamila]

...wrong post