🚀 go-pugleaf

> My car recently blew a freon hose and lost quite a bit of A/C oil and
> all its freon.  The service manual says to use a vacuum pump to evacuate
> the lines (to eliminate any possible water) before recharging.
> 
> My question is: assuming I do this, how do I know if I am adding enough
> oil?

I don't know how much oil you lost.  Why do you say it is a lot?  What
you did lose would spray around a lot and look very messy but the amount
could be small.  In the GM shop manual, they tell how many ounces to add
when replacing each component of the system.  They also talk about
draining and measuring the oil in each component to know how much to put
back.  This would of course be major.   But I can't believe a pin-hole
leak would cause much oil loss (just an opinion).

As to the evacuation, intuitively it would seem that more than water
vapor is being removed here.  There is also air (a poor refrigerant) to
remove.  Low side pressure is in the 20 psi range so having air in the
system would have to dilute the freon - this doesn't sound efficient.
(Again an opinion.)

You may be able to repair the leak yourself by changing the hose (using
NEW O-rings) then letting a shop purge and recharge the system.  I can't
believe a hose patch is a good choice if you intend to keep the car for
any length of time.

	Steve Falco