Non-Audi A/C questions

[Tony Hoffman]

Mike, you are on the right path. Question # 1, why is the expansion valve
bad? If it's plugged, probably time for a compressor. I'd start with a set
of guages, as this will give you an indication as to the condition of the
compressor.

Basically, you are looking ofr a significant difference in the pressures.
If there is not, the compressor is bad. A condensor can be cleaned, BTDT
plenty of times for customer cars. Use a good AC flush and go in the
reverse direction of the system flow.

If there is a huge difference (the high side goes too high and the system
shuts down, then you have a restriction in the system, not necessarily the
expansion valve, but it's a possibility. the R/D is the other, and
obviously you are looking at replacing both. The chances of the condensor
being plugged are very low, as it is a parallel flow and all the tubes
would have to be plugged at once, highly unlikely that would happen before
the expansion valve or R/D plugged up.

So, hopefully that gives you a good start, but yes, buy a decent guage set
and start there, trust me, either way this will save you $$. Probably a
little now, but you always have them for later as well. For me, a high and
low reading are one of the first steps in AC troubleshooing, along with
vent temps. That is, after confirming the compressor clutch is functioning
and being engaged.

With the guage setup, adding the R134 is easy, and you can watch the
pressures as well. You will have to guess a bit on the amount this way,
unless you have a very accurate scale you can set teh cans on to wiegh
them. This is how the professional machines work, they weigh the
refrigerant and maeasure the weight difference as it's added.

HTH,
Tony

On Sun, Jul 15, 2012 at 2:23 PM, Mike Arman <Armanmik at earthlink.net> wrote:

>
> Here's question #1 - do I need a condenser? The system has not grenaded,
> is not full of air, it just cools poorly (but it does cool). The reason
> everyone says I need the condenser is that once contaminated with bits of
> busted aluminum from a blown compressor, they can't be cleaned, but my
> compressor isn't busted so I don't think the condenser is contaminated.
>
>
> So here's my plan . . . change the expansion valve first, then the dryer
> (per instructions, adding some ounces [I have the number, just not in front
> of me] of oil to the dryer before assembly), using new O rings and seals
> (have them) as needed, evacuate system, add correct amount of R134 (which
> is 21 to 22 ounces, just under two 12 ounce cans from a completely empty
> system).
>
>
> I'm trying to avoid changing the condenser, and I'm trying to avoid buying
> a gauge set.
>
> Question #2 is therefore: If I start from empty and add the correct amount
> (just under two cans) shouldn't the pressures be OK?
>