Success!....(sort of)

[crashone]

Well after trying the evaporator cleaning without taking the dash out I'm not so sure how well that worked. I was able to replace the foam rubber spring drain hose with some new clear tubing that allows me to see how much is draining. I am getting more water out of the passenger side drain than the driver's side drain. Is this normal? I used an air compressor, garden sprayer and shop vac to try and get that cleaned up. However I guess plan "B" is to take out the dash and really see what I'm doing. Also while in there I replaced another piece of foam hose on the passenger side, disconnected the vacuum pods so I could shut the air intake door tight so I could see if the car got cooler, it does. Now I have to finish hooking up the vacuum lines so that the intake door will stay shut when in recirculate mode. I also put some new seals in the fan cover slots to help seal them up, I don't know how much that will help but its done. Its been a tad roasty around here!

[biopete]

Is there a previous therad that offers some background? I doing the diesel gian Ac repair with new parts. I flushed everything tonight and put on expansion valve. Do i have more to look forward to?

[crashone]

I was referring to a precious thread about cleaning the evaporator without removing the dash etc. I still get good cold air ~40* on low speed but in high speed the temp goes on up to 55-60. I also noticed that the expansion valve is not insulated 100%, the lines are but not the valve box itself, I am going to wrap that with some foam insulation tonight and see if that helps any. If all else fails it is on to plan "B" when I get a free weekend (yea right!).

[techguy512]

Originally Posted by crashone

I also noticed that the expansion valve is not insulated 100%, the lines are but not the valve box itself, I am going to wrap that with some foam insulation tonight and see if that helps any.

When I redid my W123, I bought a new "expansion valve housing" which is the 2 piece foam insulator that encapsulates the exp valve front and back.

$5 at the dealer....

[Mismost]

Crashone...these systems allow about 20% fresh outside air (read hot air)...so to my way of thinking, the slower speed draws in less hot air, you get lower temps...high speed pulls in more hot air and you get higher temps at the nozzles...that and the faster moving air just has less time to cool off as it get blasted through the evaporator

I bet at night, the difference is much less as the outside air is somewhat cooler. I re-routed some vacuum lines, now have no outside air allowed, and much improved cooling as a result. If I want fresh air, I open a window!

Originally Posted by Mismost

...that and the faster moving air just has less time to cool off as it get blasted through the evaporator

That's the main reason you get lower vent temperatures at low fan speed. Think of it like this, if you double the air flow through the evaporator you may increase the heat transfer by 50% and remove more total heat from the cabin. However if you increase the heat transfer by 50% and the air flow by 100% the final vent temperature will still be higher.

Having outside air flow will also affect the temperature, especially on very hot/humid days. There is a compromise between having maximum cooling and not having to breath 100% recycled air. Don't forget that back in the 80s some people still smoked in these cars, having some outside air helped prevent them from killing their passengers as quickly.

[crashone]

I have the vent door wedged closed right now. My vent thermometer has been reading 120-140 when I get in at the end of the day, I know thats hot but the newer cars seem to cool off pretty quick in the same weather. I leave the window open while the compressor starts cooling off. I need to finish the vacuum set up so I can put the glove box back in. Anyway my engine seems to get hot now so I am going to flush and fill this weekend. Also replace the thermastat, hoses, and monvalve so I can rule those items out. Hopefully this will help, if not on to plan "B"! Thanks for the advice and replies.