air conditioning refurbishment

[peeeot]

Hi! It's starting to get pretty hot around here and as much as I enjoy riding around with the roof off in my Zagato, traffic is rather congested almost all the time and the all-black-leather-interior will occasionally try to bake me alive. Actually it's never insufferable, but my a/c doesn't work and it's taking up space under that oh-so-cramped hood so I figure it might as well be able to do something when I ask it to. I've investigated refrigerants, but I'm far from knowing the best way to go with getting the system back on-line. It hasn't been used for at least a ear and I don't believe there's any fluid in it at all. The compressor doesn't click on or anything when I press the buttons, but I figure that's because there's nothing in the system. A guy told my if I were to switch to r-134 without replacing the seals in the compressor itself, the system would crap out for good after maybe as much as a year. I've heard about refrigerants that can be used without any modification to the r-12 system, but that they are flammable and therefore a very bad idea. What's the best and cheapest way to get the system functional? One other random thing-- my manual says the Zagato should weigh 2750 pounds (curb weight) and any other source I've seen has put it at comfortabley under 3000, yet the panel in the door lists GVWR at 3470 pounds. Which is correct? The 3470 would account for the 19-ish MPG I've typically been getting... that's a lot for just 108 HP to pull around all the time (right?).

-Peter

[Bill Gorelick]

Peter,I went through the same thing a couple of years ago. Probably the best thing to do is to take the car to a knowledgable A/C shop. Have them do a vacuum test, if the system holds vacuum(no leaks) then have it filled with R12. The service will run about $80 and the R12 runs about $70 per lb,takes 2 to 2 1/2 lbs to fill the system. This will give you the best performance from the system. If you have other problems,that would be the time to consider changing to R34A..Good luck..Bill Gorelick

[peeeot]

Thanks Bill... that sounds like a reasonable solution. I've heard mention that when an A/C system doesn't get used for a long time and there's no fluid in it that you have to replace the reciever/dryer because of a dessicant bag inside that acts as some sort of a filter. Is that true, or can it be ignored?

[Bill Gorelick]

Peter..I am by no means an expert,however,once you start down that road you might as well replace the Compressor,Hoses, and anything else that it needs. A new Dryer will cost about $75 to $100 plus Labor..Then you still have the other expenses. You said you wanted to do this inexpensively? It cost me just under $1000 to re-do my A/C system completely. By the way,just because the Compressor does not come on,does not mean the system has nothing in it.There is a Safety Switch that prevents it from running when the pressure is too low(low on Freon)..Again..Good Luck..Bill G.

[Ken H]

On the A/C, you don't need to replace the hoses when going to R134, as long as they've been run with R12. R134 will give you less cooling capacity than the R12, so don't expect the same performance. Replacing the receiver/drier is a good idea in any case.

GVWR is the GROSS weight which includes maximum recommended passenger, luggage and gas load.

- Ken

[Allen Lofland]

Old r12 units are potential money drains, be carefull.... Ask lots of questions and read up . Get a book and get smart.
Your system might be in very good condition, first as someone said, evacuate the system and see if it holds a vacum . If it doese YOUR in luck. If it dont. it's probably 134a time. New compressor is $200.00. expansion valve $35.00 hoses will be ok in general, each one will be tested and replaced as needed. No need to go throwing good parts away. The condencer in front of the radiator is the week point in a 134 system, r12 uses a smaller one than 134 likes. This is overcome ususally by an electric fan that runs all the time when the AC is on. Lancai already did this :)
I have converted several at home myself and have had very good results by getting my own vacum pump and gauges and haynes ac book, also the web has lots of help. It's not rocket science.... I have a new 134 system on my Scorpion that I have been battleing with for a couple weeks, works fine and then it goes warm again, acts like a leak but I cannt find one. I WILL fix it eventialy, if I was haveing a shop do it, auuuuk is would cost a fortune.
Vacum pump, $150.00 Gauge set $50.00 134a gas $4.00 can R12 $40.00 can...see why you go 134 gas if there's any work to be done to the system.....Also keep in mind, they have found out that most of the old thoughts about r12 and 134a not being compatable are wrong. The new and old oils seem to coesist fine, the o-rings seem to be ok with out changing. If you have a leak, you change it, if you dont, leave it.
If you want to learn yourself, you will save a lot of money and be able to do other cars later. You will find friends you never new you had :) lots of luck

[peeeot]

Thanks so much for all your help! As soon as I check vacuum on the system I'll let you guys know how things go.