AC Issues

My truck is a 98 Taco SR5 V6 5VZ-FE, the AC Compressor goes out. I
replace the compressor and research what oil to put in(PAG), how much
1.9oz, and then had PepBoys recharge it. During the recharge, the
technician tells me that when he hooked up to the low side, it showed
85psi, and that was too high, he's not touching it... I convinced him
and he continued. When done, the AC blows cold for 5 minutes, then
gets hot. I put a pressure guage on it, and it's showing 75psi for me,
which is too high. Now, after a couple of days, when the motor is cold
in the morning, it blows cold for 15m, then gets hot. In the middle of
the day when motor is hot, no coldness at all...

My questions are:
How many oz of PAG SHOULD the system have?
How did he "over charge" when he's got a better guage then me?
Is there an easier way of evacuating a system than having a machine
doing it?

Am I right in assuming, it's got too much oil, not enough refrigerant,
and too much pressure?

BTW, the expansion valve was changed as well and is NOT clogged, for
the record.

Thanks, just curious....

RedForeman
with 176,356 miles and going strong.

"RedForeman" <RedForeman@gmail.com> wrote in message news:1153242531.046683.99960@35g2000cwc.googlegroups.com...[color=blue]
>
> My truck is a 98 Taco SR5 V6 5VZ-FE, the AC Compressor goes out. I
> replace the compressor and research what oil to put in(PAG), how much
> 1.9oz, and then had PepBoys recharge it. During the recharge, the
> technician tells me that when he hooked up to the low side, it showed
> 85psi, and that was too high, he's not touching it... I convinced him
> and he continued. When done, the AC blows cold for 5 minutes, then
> gets hot. I put a pressure guage on it, and it's showing 75psi for me,
> which is too high. Now, after a couple of days, when the motor is cold
> in the morning, it blows cold for 15m, then gets hot. In the middle of
> the day when motor is hot, no coldness at all...
>
> My questions are:
> How many oz of PAG SHOULD the system have?[/color]

In the compressor, condenser, reciver, or whole system?


[color=blue]
> How did he "over charge" when he's got a better guage then me?[/color]

The gauge pressure # in a system that is not running will be the same
either way and relates to tempature, not the charge.


[color=blue]
> Is there an easier way of evacuating a system than having a machine
> doing it?[/color]

NO.

[color=blue]
>
> Am I right in assuming, it's got too much oil, not enough refrigerant,
> and too much pressure?[/color]

No.
[color=blue]
>
> BTW, the expansion valve was changed as well and is NOT clogged, for
> the record.[/color]

What about the reciever/dryer? It was replaced right? Some of the oil is in there too.
Was the condenser flushed? (bad compressor right) Some oil is in there too.


The sight glass should be liquid on a running system. Bubbles indicate a low charge.
The sight glass should bubble and foam when the compressor cycles off. If it remains
liquid its over charged.


It sounds like a wet system to me. Maybe contaminated oil from the old compressor.

[color=blue]
>
> Thanks, just curious....
>
> RedForeman
> with 176,356 miles and going strong.
>
>[/color]

GL
Dan