Dash Change Out - HVAC Renovation

[SpecialDelivery]

OK so for those of you who know or don't, I scored a crack free dash from the junk yard! The plan is to when I change it out, renovate my HVAC system. When I first got the car, I charged the AC and it worked for two days...YAY! So I figure that most of the system is working save a leak or two. So I plan to re-charge it with some dye and see if I can find the leak(s). I know one or more of the pods are shot, so I took all i could from the dash donor car ( I couldn't get the "one in the back" out of the car the one behind the Heater Core (and evaporator?) box in the middle....

First let me promise that I will document this thread with pictures of my progress and results...I believe in contributing so that others may learn.

The purpose of making this post ahead of time is that I need / want to buy all the parts needed prior to beginning the swap, so as to have minimal down time.

My automotive HVAC mentor buddy, Ed (he's got 40 years experience in the biz) suggested given that the evaporator and heater core require dash removal to definitely change them out while i have the dash out. I agree. He also suggested that since the compressor is just an engine accessory, that if the one in the car is working and not leaking I might want to leave it alone. I'm not sure I agree with that one yet, I'm thinking a fresh system might be the way to go, considering I'm in Florida and Automatic Climate control is a very nice idea to me.

So, suggestions on how to trouble shoot the Temp rheostat? sensor? The vacuum change over valve? ( I have on I pulled from a 1987 SEL, it's different from the one in my car so I DK if it will swap in, doubtful....anything else I should check out prior to the main event?

I'm partial to buying from FastLane to support this site, given the scope of the project I am shopping around for parts.

My Automotive HVAC mentor said to get an evaporator, and a receiver dryer) while I'm at I figure and expansion valve and orifice tube....what about this farging bastage Mono Valve? How do I even know if I have a heated windshield? Anything else I should replace while I'm at this or test prior?


Anyway the main questions are ...

1. What is the difference between the OEM AC-Delco and Four Seasons compressors? Rock Auto lists a Four Seasons Compressor and FastLane shows an Air Products, both about the same price...anyone have an opinion as to which one is better???

2. Rock Auto lists Four Seasons Evaporator for 115 and there are FOUR choices on fastlane....all of them 60 or so dollars more expensive...so question number whats the difference between the Behr, ACM, Nissens (with and w/o valves, I do want a valve right?) and Modine ( which says Prime, whats that mean?)

Now on to the heater core... Rock Auto doesn't even list one...good GRIEF that thing is expensive to replace as PM item, but it's not worth pulling the dash again at 7 hours plus round trip.

Ok so what else should I look at?

As always, ALL comments / ideas, help, suggestions etc are appreciated!!!

[SpecialDelivery]

ok so I put dye in the system, charged it, fired it up and the compressor started making some HORRENDOUS noises...which I'm told by Ed, could be a loose belt...told him I doubted that, we shut it down and found the compressor leaking dye...badly it still turns so I know it's not "locked up" but does leak so out it comes...

so OK i'm sold on replacing the heater core and evaporator while I have the dash out....and obviously the compressor

BTW after reconnecting the red n green vac line ( not leaking) I BELIEVE all my pods are working

any suggestions, etc?