(2001 Dakota, 4.7l v8 engine. I've mentioned the AC before.)
Ok, so it's already known there's a leak somewheres in my AC system.
Mechanic recommended waiting until spring to fix it. I attempted to
fill it in the fall, went through a can and a half of refrigerant before
I gave it up as a bad job (gauge never read sufficient pressure).
Was able to use my defroster the entire winter with no probs until
Friday, when the motor started making noises again.
So, on this beautiful Sunday afternoon, I went back out with my can and
gauge, popped that lead off the cannister and shorted it, fired up the
truck and loaded more refrigerant. All was going as expected - the
gauge indicated slight increase in pressure but still not enuf - when
suddenly the truck made a noise like the AC came on - or off, or
something - and the pressure gauge shot up to full.
Was that supposed to happen? I immediately stopped, turned the truck
off, set all to rights - and heard an extended hissing like air escaping
in the engine - sounded like it was below where the low pressure valve
is, but closer to the engine block. Eventually it faded. When I fired
her back up, the AC - for now - is working properly. But why did it
suddenly... I'm not a mechanic you understand, so I'm not quite sure
it suddenly did.
Last time I spent a lot more time trying to load r134a in, and the
engine/AC sound never changed the whole time. I've no idea if the fact
that it did this time is a good thing, or a bad thing!
Oh, and does $1500 to fix the leak, which I'm told is in something
behind the firewall(since I can't find dye around the engine block) a
fair price? Seems high to me.
Any advice appreciated!