Expansion valve, need advice

[J.HIDALGO]

Well, my expansion valve is leaking again (second time in less than a year). The AC system works great when is full of freon. It seems that the leak comes from the front of the valve. I have the dye in the system so, it is very obvious. I changed the o-rings and also a new expansion valve was installed. Vacuum , flush, etc. The question: how tight (or loose) do the fittings in this valve need to be? torque values? I still have the R12. Is there a sealing compound that I can use?

Is it leaking at a fitting, or at the bulb at the top of the block?

Good luck,

[Benzmac]

The O-rings for this have been updated. I get mine tight, even on the small 3mm allen bolts. I oil the o-rings and both sides of the fittings. Then pull it together very slowly 1 turn at a time on each bolt alternating.

This will give even pressure on both sides of where the o-rings contact the valve.

Brother of The Benz, jhildalgo
It appears that the "HOT TOPIC" is A/C and it's problems.
I too had a leak in that area, but it was the evaporator leaking.
Many sticks of dynamite later, and after 14 years of service, the evaporator/heater/blower housing has been rebuilt.
Because of my physical condition(too short, too fat and over weight plus too dumb I decided to has the system totally rebuilt by my favorite technican, Larry(not related to the Bible, Larry).
The following was replaced by M/B new or rebult components, starting at the front.
Compressor
Clutch
Drier/reciever
Expansion valve
Evaporator
All new gaskets and seals
All the vacuum elements
Blower motor assembly
A bunch of little things
Nothing was not replaced that would require the disassembling the A/C System.
It took 3 days shop time at a cost of $4100.00.
Considerring an Escort with minimum down payment would have a $303.00/month payment for 60 months, in thirteen months I will have this debt cleared.
There is no end to what we do to keep our ole Benzes.
I'm the original owner of this 1987 W-124030, it has 176,000 miles and this is the original A/C; not bad for 14 years.Cost me $24.40/month for driving comfort. Maybe I'll get the same return on my investment(ROI).
She'll be cooling using R-134A, good-bye R-12.
Happy Trails Beep Beep from The Spiderman in Houston!!!

[wjm]

FWIW...

My mechanic told me that if the aux fans are not working properly (ie, not turning on at 1/2 speed when A/C is on and at certain pressure level) then these problems tend to reoccur.

Willy

[J.HIDALGO]

It must be O-rings. AHRRRRRR, I did it very slowly last time. Obviously, not carefull enough. Thanks guys for the advice. The leak seem to be from the fitting/O rings at the front of the expansion valve.
Donald, I already replaced most of the stuff you listed, including the evaporator. The expansion valve is cheap comparing to the rest of the AC system but, it is a pain to replace.
I guess is time for R134 conversion and another expansion valve.
Thanks for the advice.

Brother of The Benz, jhildago
Like my 300E, I'm wore out.
Physically there was no way I could do the replacing of the evap core and all that is associated with it.
Joan and I will put off some vacations to restore the cost of the repairs.
It lasted 14 years on the original, if we get 1/2 that on the repairs we'll be happy.
Heed to the helpful hints about tightening the retaining screws and you'll have it this time.
Wouldn't it be a joy if all of the other parts were as inexpensive as the x-valve?
Happy Trails Beep Beep from The Spiderman in Houston!!!

[J.HIDALGO]

Donald, aka. spiderman, aka. el cheapo. I was reading the archives and, did you change/switch over r134 not too long ago with a kit from K-mart? Since you live in Texas where the weather is probably equivalent to Florida (where I live), how is the cooling with R-134 vs. R12. I know a lot of people asked this question before but, I would like to hear your opinion. What happened to "el cheapo"? Just curious...
Thanks!

Brother of The Benz, jhildago
El cheapo still has his little tricks for we Benz owners,goto http://home.eartlink.net/~asherson/Don and have a look see. I still have the literals via the E-Mail. El Cheapo was replaced by The Spiderman after a serious runin with a spider bite and the spider won the match. I spent 10 days in quarnateened infectious area. I'm still recoverring after 2 months.
I did convert to R-134A using a kit from "interdynamics".
I followed their instructions and the system performed marvelously.
It was the compressor, that after 14 years of faithful service, gave up the ghost.
In deciding to keep my purchased new 1987 300E, Joan and I opt'd for the complete rebuild. Putting this item behind us.
Now with the new A/C we had R-134A as the refrigirant.
It's not as cold as R-12, but how cold.
In Houston we experience a similar climate as you in Florida, and you will not suffer any.
Consider the new autombiles us R-134A!
Happy Trails Beep Beep from The Spiderman in Houston!!!

[J.HIDALGO]

Thanks Donald for the inside info. I will convert this coming weekend...

Brother of the Benz, jhidalgo
Sometimes I'm so far out in left field that I feel my effort is waisted.
I just stopped a discussion on packing front wheel bearings that seemed it would go on and on with neither side winning or loosing, if there are winners or loosers.
I just quite.
Did you look at the El Cheapo gadgets?
Happy Trails Beep Beep from The Spiderman in Houston!!!

[J.HIDALGO]

I saw them before. Cool stuff. Thanks again.