Jerry 87 928S4

Read the 928 manuals and instructions that came with the kit. But since it is the first time for me here is the plan.

Plan:
1) release pressure from system (R134)
2) disconnect clutch wire
3) remove 2 lines and dryer
4) remove 2 lines and compressor.
5) reverse install - careful with the O rings.
6) evacuate system and refill

Anything to watch out for? - other comments appreciated.

I know it is 20 degrees ( Chicago) outside but figured it was a good time to do it

Dozman

There has been many topics in the past on this. Might want to research it. Hit the search topic, use a/c, R134a, etc...

I am not being cynical, but there are a few things to watch out for.

A few things to watch out for are over charging (R134A needs about tweenty minutes to circulate and redistribute throughout the system. If you do not wait, you'll see you might over charge the system)

Definitely need to ensure no air is admitted after evacuation to below 500 microns (It's always a good idea when you are evacuating to turn the compressor shaft by hand 1-3 revolutions slowly to release any trapped refrigerant or non-condensables in the compressor.

If you replace any major part of the system, you should readd the suggested amount of replacement oil, as it is recommended in the manuals.

John D

MikeN

Thats about it if that is all you want to do, but
ANY time I have opened the A/C system on a 928 I have replaced every O-ring in the system along with at least the front expansion valve.....last
time I did both front and rear valves. Why?...so hopefully I won't have to touch it again for years. Yes it takes time and is a little more expensive, but this way you don't have to open it up every 6 months to replace another leaking O-ring, bad expansion valve, etc.
My present GT had about 10 leaking O-rings the last time I revamped it, now it has none, and hasn't lost any freon since....still a full charge.....colder then any of my other cars.

dr bob

FWIW, cold weather is not the time to be trying to dry out the AC system with the vacuum pump. I have no idea if you system has any stray moisture in there already, but since you choose to replace the drier there must be a reason.

Moisture in the AC system needs to boil and get sucked out through the vacuum pump. At 20f, anything that's condensed in there has frozen in there and won't boil off very easily. Do you have access to a heated garage? Ideally you'd like to get the car as warm as possible, and it definitely needs to be above the dew point inside the system at whatever vacuum/press you can muster with the available equipment.

So, why are we replacing the drier anyway?

It's 82 in sunny Glendale, Ca today... <img border="0" alt="[icon107]" title="" src="graemlins/icon107.gif" />

Jerry 87 928S4

The noise I was hearing turned out not to be from the AC unit. However, since I already bought the griffiths unit and had help to install it ( and it was just sitting in the garage) - done it is!

That was quite a job although I have to say it was a perfect fit. The more I work on my 928 the more certain I am that mechanics earn every dollar. It took about 5 hours but then I struggle just removing the belts

I am going to list my old compressor and dryer on ebay if anyone is interested.

Again, appreciate the advice I received.

WallyP

You should never install a used A/C receiver/dryer, so that is trash.

Jerry 87 928S4

I agee, but will toss it in the package anyway.