yep, the thermal adjusting heater valve.
cable controlled, but a thermal spring keeps it at a varied flow through the core for a more stable temp.
hard to find and any oem unit is most likely to leak.
my set up is the way to stop all hot water from your core. but my controls are a little involved.
if i could draw with this crazy comp. i could show you the wiring and such. but i might have to scan my papers and post them that way. its not to hard if you do some wiring.
same with the fan system, its not that complicated. i have put it in a few set ups and the its safe for almost any fool. including myself. my auto side has covered my butt a few times.
"Black Death", Ford was one of my most common veh. as im sure you see your fair share of them for other repairs.
if the pump hasnt grenaded, then even some grey to black flim can be dealt with. so systems i would put a filter and switch before the condenser (switch is a hi pressure cutout so if the filter plugs it will break clutch circuit).
this will save the condenser from chunks. a little more plumbing and kind of tight in our cars.
yes the new stuff is much tighter in the passages. but 134 is smaller, and they are trying to get more surface to volume in the new cores. our stuff will pass some bigger particals but crap is crap! it gets stuck the same way and wont come out!!!!!
you got the idea right about capping and soaking the cond. sludge type crap might need to soak, but if its that thick, you might want to look closer at the pump. look for fine flakes of silver or Teflon at any joint, 90* or place that a flake might stick. find just one and you can count on way more then you want. Fords made black death a real thing. but other systems wont always color up, and will just sent flakes with out any wear warning. (whitch is what it is . the warning sign that its wearing)
the condenser i use is not a bolt in. not to many of my things go in that easy. its a fab. make fit type thing.
the side wings under the core support have to be cut out on the pass side for air flow to the cores. i also made my own line from cond out to drier in and used a std, #6 x#6 (o-ring) drier that is easy to get and not as costly as "the proper unit"
it was a theroy that proved out right, that cause 134 expands so much more then r12, and oem was moveing to big cap condesners. so i found one that almost fit and had more volume the the 75,6,7,8 units. helped lots.
same with rad. i had a bigger hole, so why not go to the bigger rad.
so you can see the extra size on the cores. from the filler neck over is all extra over the oem size.
i think i did the math way back when, and it was something like 8 or 10 % more on both the rad and cond.
so that sends me to charge amounts with 134a.
60-90 % of what the r12 amount is.
i cant even give you some round numbers cause its been so long. i will try to find my folders so to give you some better idea of the fluctuations, even with in the same model of car. (like i said, i have over 300 logged, good thing i kept records of them, and took them with me when i left.
that is hit and miss rule, but works with most systems.
i dont remember what my charge is, but i also have extra stuff in my sysem that messes the rules all up. things like a "suction throttling valve" , STV. its suppose to keep my evap at said pressure no matter how much the pump sucks under set pres. its a neat idea that i think helped "my" system some.
i evac and charged so many times that even MY records dont list all of them .
some where around 100.
every time you evac, you remove oil. most times you cant tell how much, others you will get a oz. or 2
it depends on where the bulk of your "flowing" oil is when you recover.oil sits in a small "sump" in the comp.
most pumps "start" with 6- 8 oz. of oil. then 1 for the cond. 1 for the evap. 1 for the drier.
(2 for duel evap).
some times if there is a lot of hose, you might add 1 more.
this on the thought that all units are new and or flushed dry, and a drained comp.
ok next up,,,
so you said she worked for a few days then leaked out,
you should beable to find a wet spot some where, at a fitting, the comp seal (at the front nut and behind the coil)
if you cant find a spot, the it could be in the evap box at the ex valve,
you can, if your good and lucky, take your small mirror and look inside the freash air/ rec box on the very far pass side. look towards the core. i believe the valve is visable from there. also look at the face of the evap core for lint, bugs and gen crap. you can clean this all when you break the box open to change valve. i like to know what is leaking BEFORE i open and clean things.
you asked,,
"One more question for ya before I forget to ask- it seems no matter what position the airflow mode lever is in, I ALWAYS have blower assisted, outside air coming out through the vents in the center console. Both my 79 TE51's the same. Does yours do that too? Normal or a problem? Think the cables are adjusted properly, cause air is directed to the defrost vents, when the lever is in "defrost" and air is directed to your feet when "heat" is selected. Seems theres no way to control or shut off those center console vents. The owners manual is pretty vague in their description of operation...any thoughts?"
sounds like the flap from dash to lower is leaking. maybe. a lot of time the foam seal around the flaps fails then leaks air. some thing you will see when you open the heater box for the core, look at seals and foams and replace or improve as needed. im sure you can figure out what to do when you see it. the worst part is getting the dam box out. full console removal and center dash stuff. oh what fun.
heater core is cheap!!! replace it. napa can get them. and you dont what to pull it twice LOL
our air flow system it funky. it wasnt intended to have a/c. so it was a easy add in between the fresh/ rec box and the heater box. so, you can only blow hot air to the floor and def. but you can blow cold to any position.
also, some side vents only opened to outside air and didnt hook up to the air/ heat sysem. others did.
look under dash at dr side and see if the ducking goes to the firewall or is there a duct that run under steering.
owners manual is very crappy for anything more then where the fuses are or how work the the shoulder belt adjustment LOL
"OK, that should keep your head spinning for a while! HA! TOLD you I was gonna become an annoying PEST!"
nope, my head is always spinnin, (i try to keep it that way, works best for me that way)
and i got more to say then you will want to hear at some point
youll learn
have a good friday
ken