Cannot reach A/C high/low pressures

Sounds like your compressor isn't any good. Is the needle shaking or does it hold steady? Overcharging the system would only make matters worse. Did you happen to manually turn the compressor hub before letting the clutch engage? As far as I understood, the amount of R134a compared to R12 should be less. Something like 80% was it? Putting in 1 lb R134a compared to 1.1 lbs R12 is only 90%.

Could be a leak, too. THAT much 134a must be going somewhere.

wws

Yes, I manually turned the hub before letting it engage. Both pressures appear to be steady. But I agree that the problem could be the compressor. What I am afraid I might have done is put too much oil into the compressor ports. I put about 3/4 oz of the oil into the compressor and distributed the other 2 oz into the condensor and evaporator. In any case, it does sound like the compressor has gone bad. Any chance I can dismantle and repair it?

I don't think that too much oil is the problem in your case, unless previous repairs involved the continuous adding of unnecessary oil. The compressor (a reman unit that you have no previous experience using) could have had a stuck or bent high side reed valve from the factory.

I like using Poly ester oil (what you used) in R134a coversions when it is going to mix with mineral oil. I don't think the quantity or type of oil is the cause of the problem here. The compressor probably came with oil in it, but adding less than an ounce shouldn't spell disaster.

Any chance I can dismantle and repair it?

I guess your compressor DOESN'T have a warranty? If it does, then see if the parts house will honor it -- this also may involve an inspection for the type of damage -- lack of oil or too much oil for example can cause compressor failures that are not covered by typical compressor warranties. Unfortunately, if you got one with a bent reed valve, they may still blame that on too much oil on startup. Make sure you explain the preventative steps you took during installation.

If you really put TWO POUNDS of R134a in your system, then that is dangerous! I'm not sure it would physically take that much liquid freon on such a tiny system. Are you sure that you put in that much -

32 ounces? Cans are 12 oz each. If there was a rapid leak you would be able to hear it. Make sure your high side gauge is accurate before condemning the system. Put it on another working system to check. The 25 lbs low side isn't too far from normal on a mild day; it also depends on the proximity of the fitting to the compressor.

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Yes, I did put in 2 cans and then added about good part of a third can. So that amounts to nearly 30 ounces. I did not hear any obvious leaks. But I did hear momentary hissing from the low-side valve while I was charging. It was such a short duration I doubt it could have leaked 1 lb of freon. I checked all the connections, and I don't see any sign of oil seepage. One possibility is that a leak could be inside the evaporator. But the system held a 30" vacuum for nearly 6 hours with no drop at all. I would be surprised if there is a leak.

Unfortunately the compressor does not have warranty. It only had a

90-day warranty, and I kept it for almost a year before installing it. If I can't fix the compressor myself, I will have to trash it and buy another one. Is there a way to check the compressor operation without charging with freon?

The noise you heard from the low side fitting may have just been the rush of freon into your system during charging.

With a leak test of 6 hours, it is unlikely that you have a significant leak, with the possible exception of your schrader valves (because the gauges were hooked up to them at the time).

The best, easiest way to test a compressor is on the car with a properly charged system. Evac and charge the system with the correct weight of freon, probably .9 oz R134a. Double check your book figure by looking in the engine compartment for an A/C label. Use 85% of the R12 amount listed. 1.1 lbs sounds a little low even for a Metro; I usually trust the car decal over a service book.

Finally, I would say that the compressor is bad based on your pressures, but again, make sure your gauges are accurate.

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I'm pretty sure you already know this but you're using R134a and Freon synonymously in your posts. It should be noted that Freon refers to R12.

Dupont invented the name Freon to encompass several CFCs AFAIK. I use the word freon just like I call colored wax sticks crayons. 'Refrigerant' takes longer to type esp. when you are using the word alot!

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Then I guess I should have said, "R134a is not Freon". I agree that it takes a lot longer to type refridgerant but I didn't want to perpetuate the misconception that all refridgerants can be referred to as Freon.

If you're using Freon like you use the word crayon, then you should realize that crayons aren't trademarked by Crayola. A crayon IS a colored wax stick. I think you meant something like "band-aid" or "Xerox" or "Kleenex". That was my point in mentioning the use of Freon as a generic term for refridgerant when it doesn't encompass all refridgerants, in particular R134a.

That is not correct. "Freon" refers to refrigerants manufactured by Dupont. The number after the word "Freon" indicates which refrigerant it is. Freon-11 is CFC-11. Freon-12 is CFC-12. Freon-22 is HCFC-22. Freon-134a is HFC-134a. Freon-502 is CFC-502. So on and so forth.

Likewise, other manufacturers have their own refrigerant names. Allied-Signal calls theirs "Genetron" (Genetron-11, Genetron-12, Genetron-22, Genetron-134a, Genetron-502, etc.

Elf Atochem calls theirs "Forane". Forane-11, Forane-12, Forane-22, etc.

ICI America calls theirs "Klea". Klea-12, Klea-134a, etc.

It's just that "Freon" has entered the American vocabulary as a generic referent that is actually a brand name, just like "Scotch tape" (belongs to 3M), "Kleenex" (belongs to Kimberly-Clark), "Post-It" (3M again), and in some areas, people call any brand of color crayon a "Crayola" (belongs to Binney & Smith).

I thought Crayola invented the name 'crayon', i.e. a guy named Abner Crayola III starts a business making crude wax novelty suppositories, and by way of accident, realizes their potential as wall decorating implements for small children -- I think I will name them "Crayons"!

Oh well, as it is terribly unimportant, life goes on...

Toyota MDT in MO