Hi,I have a 98 Q45T with about 90k miles and I need to recharge the A/C. Does anyone have a procedure for doing this?
Thanks very much!Randy
98 Q45 A/C recharge
Depends on how "exact" a charge you want. A lot of people will buy the DIY fill cans at Pep Boys and put in half a can at a time until the cooling returns to normal. That's assuming everything else is working fine (condenser fan, compressor, etc). Make sure you fill at the low-pressure side. The fittings should make it foolproof, though, since the low and high sides are different.
If the car uses R-134a (not sure what year they switched) then as far as I know yes, you can. All fittings are standard for that refrigerant. They tried to standardize for the R-12 too, but there are some variations in fittings from heritage use. Before the environmental concerns, R-12 was pretty much the only fluid in use, and there wasn't too much concern about mixing different refrigerants. Anyone remember when freon was less than $10/case, and people would open a can over warm soda or beer in a cooler to chill the drinks? R-134a systems have quick-connect fittings, similar to those on air compressor lines. R-12 systems usually have 1/8" or 3/16" npt threaded fittings.
I'll add, in case it isn't obvious, that low refrigerant might not be the problem. Something else might actually be malfunctioning, and the refrigerant level may already be fine. R-134a systems can only be properly filled by weight, and overfilling will cause a drop in performance. Adding a little R-134a and hoping for a fix is probably the cheapest route, kind of like throwing parts at a problem if the parts are cheap and the labor negligible. But it is by no means a guarantee and you need to be aware of this, since there are potential hazards with overfilling a high-pressure system aside from the cooling performance. A cheap gauge-set can be bought and used to aid in diagnosis, and to get you "in the range" of properly filled. R-12 systems have a sight-glass on the receiver-drier to aid in system diagnosis.