expansion valve killing me

[E150GT]

I know there are many threads out there and i thought i had read them all to get the expansion valve off my 86 420sel, but man I just cant do it. ive heated wrenches and all kinds of stuff but i cant get the top lines off for the life of me. is there something im missing here? any help is appreciated. and also how much mineral oil do i add before i vacuum the system and can u just crack open a line at the drier and pour a little in? thanks for the replies in advance.

[danwatt]

You know, it just might be quicker to remove the whole dashboard. Seriously.

[E150GT]

That has crossed my mind bit other say that it can be done in fifteen minutes.

[dpetryk]

The amount of oil you add is related to what repairs are being done. If you have not leaked any out and are just changing the expansion valve you should have to add any. However, if you have the expansion valve out, if it were me, I would do a total flush of all system components and replace with PAG46 oil.

I dont know off hand how much oil the system calls for.

[ozawa]

do you have the special crowsfoot wrenches? make life a lot easier.

http://www.peachparts.com/diy/mb_tools/mb_tools.php?page=50

scroll to the bottom of the page.

if your system is still R12, do not use PAG.

[jim16671836]

I always thought that you need to vacuum the system which will remove the oil and then add the oil with the freon????? Correct me if I am wrong... Jim

[Matt L]

Vacuuming the system won't remove any oil, but changing the drier will.

[brewtoo]

Does this expansion valave attach from the engine side of the firewall like on the 124?

[jim16671836]

I thought that if the system has pressure that the oil is in solution with the freon??? that when the freon is vacuumed the oil also comes out???? Is Most of the oil in the compressor bearings area???

The valve in the 126 is just about straight in from the right driver's knee under the dash... It is pretty easy to access and has 4 o-rings..

Go to Harbor Freight or Sears and buy a set of metric crowfoot wrenches. Jim

[brewtoo]

The oil does circulate with the refrigerant when the compressor is running.

When stopped, the oil settles out of the refrigerant.

[mbshop]

that model is terrible. use some of the suggestions.
i think you have the tube bracing running in front.
if so then take it out first.
freon always has oil in it. so if you take freon out
then you take oil out. most items will require less than
half an oz of oil on replacement.
shops use recycling machines. these measure the oil
that is taken out with the freon. with a small repair
except for the exp valve which takes no oil i would
not add more than 1.5 oz of oil back in.

george

[E150GT]

well i got the expansion valve off, but now it wont thread back in. super frustrating.also the one i removed had r134a stamped on it and i use r-12. do you think thats why it started leaking?

[mbshop]

make sure that you leave all the fittings loose first
untill all are connected. then tighten.
the exp valve is correct. they all say 134 but are ok for 12.

george

[E150GT]

the new one dosent say that

[mbshop]

yer still ok. they have been made for r134 and r12
for years.

george