Need to get at the expansion valve - PeachParts Mercedes-Benz Forum

dpetryk · #1 07-12-2007, 07:17 PM

How does one remove the steel heater duct and the cover from under the dash on the drivers side? I need to replace the refrigerant line running to the expansion valve. I have removed the 3 plastic gray fasteners from the duct but the interior piece covering it seems to still be fastened to the top somehow. I don't want to break anything. I need help to discover the secret.

Thanks, Dave.

Roncallo · #2 07-12-2007, 09:30 PM

Quote:

Originally Posted by dpetryk

How does one remove the steel heater duct and the cover from under the dash on the drivers side? I need to replace the refrigerant line running to the expansion valve. I have removed the 3 plastic gray fasteners from the duct but the interior piece covering it seems to still be fastened to the top somehow. I don't want to break anything. I need help to discover the secret.

Thanks, Dave.

First off what kind of car. If you are you talking about the carpeted part under stearing wheel of a 560SL, then there are two carpet plugs that you remove and then with a 6" extension you can reach two nuts that retain this piec. Other 107 may be similar. I am not aware of any steal ductwork in either a 107 or a 129.

John Roncallo

dpetryk · #3 07-12-2007, 10:42 PM

OOPs. Forgot to say that the car is a 89 560sl. I saw those plugs and was not sure what they did. Thanks. I will have another go tomorrow. How difficult is it to get to the refrigerant line?

Thanks.

Roncallo · #4 07-12-2007, 11:41 PM

To change the valve it is best to be able to work through the instrument cluster opening and through the bottom symultaniously. Is is physically difficult but doable. Be sure to get a roll of insulating tape. I forgot what its called but its that black guey stuff that the expansion valve fittings are wraped in.

Good Luck
John Roncallo

dpetryk · #5 07-13-2007, 11:47 AM

Thanks John.

I have access to the connection. It looks like its going to be a challenge to get to it with double wrenches.

I have checked the 3 vacuum pods that I can see at this point and it looks like the one for the center vents needs to be replaced. It is riveted in place. I can get the 3 speed nuts off to replace the pod but it looks like the rivet holding the rod needs to be removed since the new pod does not have the rod attached. That one is going to be tuff while it is in place both to remove and to replace.

Have you done a replacement on this pod? If so how did you go about doing it?

Thanks again.

Roncallo · #6 07-13-2007, 09:09 PM

Quote:

Originally Posted by dpetryk

Thanks John.

I have access to the connection. It looks like its going to be a challenge to get to it with double wrenches.

I have checked the 3 vacuum pods that I can see at this point and it looks like the one for the center vents needs to be replaced. It is riveted in place. I can get the 3 speed nuts off to replace the pod but it looks like the rivet holding the rod needs to be removed since the new pod does not have the rod attached. That one is going to be tuff while it is in place both to remove and to replace.

Have you done a replacement on this pod? If so how did you go about doing it?

Thanks again.

I have gone this on both my 560SL's But I took the dash out to do other vacume servos inside the case.

You can grind off the rivet and put a small bolt and lock nut in place. Do a search on center vents and you will get alot of information. Also do a search on the title "Will Sadie ever run again"

Good luck
John Roncallo

dpetryk · #7 07-17-2007, 10:59 AM

Status update;

I managed to replace the vacuum POD - no problem.

I gave up on getting the refrigerant line disconnected at the expansion valve. It looked like I would have to remove the steering column and some air ducting and the fresh air vacuum pods to get enough clearance to gain access to the fitting. I elected to re-terminate the hose under the hood where it mates with the hard line. Cut, re-terminate and lengthen the hard line to make up for the loss in length. I don't want to break the connection at the expansion valve and then have a problem there.

Thanks for your help.

KCM · #8 07-17-2007, 06:55 PM

I replaced the expansion valve in a 560SL. Like has been said, it is not easy but can be done. Just need big wrenches and a lot of patience. I worked through the cluster hole and from underneath. I did not remove anything except the cluster and lower cover panel. The lines were real tight, but once they cracked loose, it was not a problem. I was replacing the expansion valve anyway, so any damage I might do to the valve would not have been a problem. There are copper washers that seal the connections that you will need. I would not splice the line, as it is high pressure and you might end up with leaks or worse.

Concerning the vacuum pods, is the defroster flap pod accessible from the instrument cluster hole? I just found out I need to replace it. The manual says to remove the console and dash, but I will do whatever it takes not to do that. Sounds like big trouble. From pictures in the manual, it looks like it might very well be accessible, though probably not easily.