Has the system ever been resealed? Did that shoppe do the Schrader valves?

 

The evaporator is the only thing that can leak behind the dash
They are supposed to sniff for freon at the evaporator drain or a vent looking for stray (leaking) freon.
IMO it is unlikely the leak is the evaporator (on the low-pressure side)

 

Well, I talked with the mechanic and watched him put the two gauges on, we lost 2.3 pounds of the 2.8 and blowing near no cooling. Ran the light over the whole of what can be reached from above
and put the truck on a lift looking for anything below, around the compressor, no color, no joy. Truck has 380K miles on it, never had an evaporator replaced. Frankly I get you comment, I don't / didn't
want it to be the evaporator as the dash in the '97 has to come out. Both Schrader valves have been replaced... mechanic has a '97 himself and said he didn't like pulling the dash but it is the only
place they cannot get to and 'see'... I have to go with that (will replace heater core two and probably the 'door' , ANYTHING else I might do while in there??? Thanks.

 

You lost 23 ounces you mean
Keep looking and look for oily hoses and oil spots on the condender
The light and the dye is for small leaks
You got a big one
Sometimes a compressor leak will mask itself as the fan is running and the dye will not stick to anything
You visually check that condenser real close with just your eyeballs and all of the hoses on the high side all the way to the orifice
Post some pics

 

Does this shoppe have a nitrogen tank and regulator? I found the AC leak on my '89 300SE with it. Charged that ******* to 350psi static and felt all the fittings, turns out the top plate on my compressor is what was losing the gas. 10oz/day worth mind you. No oil there either. I also second eyeballing the condenser as a small rock can and will make them porous, BTDT.

I doubt the evap is the issue. Dash R&R is not that awful on these, did it on my '01 Screw and need to on the Expedition for a new front heater core. If you still suspect the evap, pull the blower fan and poke a sniffer up there to detect gas.

 

I don't know about the nitrogen tank... will ask... but I Have literally hand crawled every tube, hose, both high and low, the condenser top and bottom... we have a dirt road and the dust settles 'up' so the some of the engine areas have a very slight dust covering and makes looking for any leak sort of easy... the shop is pretty good, he spent 15 free minutes when I took it back on a lift and on the ground... hard to say but that 'dust' is not disturbed ... I have removed the dash myself but now cannot (back surgery coming up in a month, might be able to move then, hahahah...) ... so the full charge was out in 8 days... will look again... thanks.

 

You have sniffed the front of that compressor a hundred times and no noise from the sniffer?
You are good to go on Dash R&R to replace the evaporator then IMO
However
I just have seen about 12 evaporators get replaced at the dealer and believe they never fixed the leak
Couple of the claims got rejected because Ford called for the evaporators and tested them. They were good and the tech got back flagged
It is so much work to pull the dash, I would isolate that evaporator with homemade fittings to test with
Isolate the evaporator and pump shop air into it up to about 150 lbs. at least
Let it sit with that pressure and listen for a leak as you check the gauge
Then you are good to go on evaporator replacement if the gauge goes down and you hear the leak
Good luck

 

ManicM... okay, so no dye seen but 'sniff', as in something else?? I would rather prophylactically replace the compressor, it is the original with 381K on it... than pull hte dash. I will ask the shop about the shop air test...it is a three person plus front desk shop and I am not sure they have 'that' time... the "isolation" is beyond me in my garage.. I have thought that, while there was no dye leak observed, that is was the compressor (it works, spins, starts and stops but somehow I kept 'feeling' that was the culprit, go figure) from the start.... I note less 'engine hit' when it comes on (used to 'really hear' it impact the engine when it came on... not now but the shop folks would never know that... AC Delco for the compressor replacement???? Thank you. PS I recall the first 'Boss' that came thru the burger palace back when I was young, a lean 'whippet'... [[url]https://www.survivor-cars.com/vehicles/614/1969-ford-mustang-boss-302] I had for some 15 years a mechanic (Dennis Cann, in La Crescenta, CA now in El Dorado, CA) who was a 'Ford specialist' (a true 'grump' but really nice) who could figure out and fix anything. He had 'numbered' Shelby Mustangs that had been trailered to the shop from distant locations, saw some original AC Cobras there and the 351 Pantera...well,
I digress, sorry... think I will just replace the compressor. Fingers crossed... appreciate your time and knowledge.

 

Yes, sniff with a freon detector
A hundred times... Before you pull the dash out

 

You have to be able to justify 15 hours to replace the evaporator is all
I think I could fabricate a set of plugs to do an isolation test in a couple of hours
Offer that to the guy to build some and test the evaporator with them
You can do the same thing with the compressor.
With 381 on the compressor I would replace that before I did anything else

 

Sounds like he, you and I could be buddies

 

My pops owned a 427 Cobra when he was waiting to ship out for Vietnam, he was in Charleston, SC. BRG. Side pipes. No roll bar. He bought it off some Lt that was shipping out. He sold it to another when he left. $6100.

Agreed with the system. 25 years old and near 400k. Do a condenser, dryer, comp, and consider a line set if in the budget. Flush that evap. I think these spec a blue FOT.

Mind the dryer, oft the spring connection is missing the spring. Learned this the hardway on my 01 Screw.

 

Well, decided to see if they have a "sniffer" and willl buy an AC Delco (or suggested compressor ?) replacement. Spring connection
in the hose/line at the top? Or? Thanks... yes Dennis was a all time 'grump' but if one got past that he was friendly and funny. My wife
had him wrapped around her little finger, was hilarious... they would joke and guffaw and he just liked her... funny how things are. When
he moved from La Crescenta to N. Ca by Tahoe, well it was devastating but he was building motors up there, his specialty.

 

I used a Denso, works well on my Screw. The UAC is kinda noisy on the Mexpedition despite being sub 30k. Some are, some are not.

Compressor R&R is somewhat of pain on the mod motors. I find it easier to do with the wheel off.

 

I buy new cheap China compressors from the big a/c houses in TX
Never pay much and I buy kits
They have worked okay for me so far
I have ran so many junk remans over the years, I am a sceptic of some of those blowing up immediately.