firemn131

Well, it was going so well!!

Car is up and running well. Idle has come down a good bit to almost where it belongs. I think my MAF needs a tune.. Daily driver again..

Fixed the mixer flap diaphragm and started the AC testing tonight, Kevin In Atlanta sent me the gauges and away I went. Thanks Kevin.


Able to pull just a tad over 28 for Vac..But it wont hold for more than 30 minutes.

When engine was out I replaced all o rings, exp valve and rec/dry, Hoses. etc
and flushed.

So I need to find my leak or leaks.
What is the best (cheapest) way with a clean system?

Should I just service it with one can (or 2) and some dye?


Thanks.

John

joejoe

I use florescent dye and small charge, document leak, recover freon and repair. Luckily I do have the proper equipment (r-12) It is quite easy to pinch/tear O rings or twist if a bit dry at all. Since you are talking cans I assume you have converted. I would do just as you suggest.

dr bob

Pressurise with dry nitrogen, then go hunting with soapy water in a spray bottle. Look for bubbles.

The refrigerant and dye method works, but has a few only somewhat obvious limitations. Consider that the dye is in with the oil, so you will be searching for new oil leaks around connections using a black light. So areas around connections get cleaned with one of those big scruples towels. So everything is scrupulously clean. Charge and run the system with the dye. Then start hunting in a darkened work area, using the black light to look for flourescing traces of oil.

Or get an electronic refrigerant detector.

Bilal928S4

If you changed all the O rings, the probable cause is leak by the compressor. Pressurize by nitrogen and use soapy water as Dr Bob suggested. Usually you can hear the nitrogen leaking. Check at the compressor pulley. HTH. Best of luck.

firemn131

thanks everyone. If I can find nitrogen I wll go that route.
The engine is fresh after an install so is very clean. I may end up doing a small charge with the 132.

Thanks

zekgb

You changed out the long combo hard/soft line from the expansion valve to the dryer? If not that's a super common leaker and pretty much impossible to change with engine in place. Greg Brown has a kit for silver soldering an AN fitting to the end of the hard line along with a new soft line run to the dryer.

Speedtoys

i believe I have this repair on my car, Greg did it. On R12 and works fiiiiiine.

Ducman82

Yup, great kit.

firemn131

How much is the lot?

WallyP

Has the car been driven a lot with non-functioning AC? Had all the refrigerant leaked out? If so, the non-lubricated front compressor seal may be worn or damaged.

Sometimes, but not too often, the vacuum leak is a dry front seal that will seal a little better if it gets some oil...

griffiths

John,

For 'flushing' a system, usually something like:
Interdynamics CA‑1: Power Clean & Flush Aerosol 17 oz; a few cans, otherwise you'd need a flushing cylinder with hose, a gallon of flush and shop air to power it.
You can flush lines, condensers, evaporators (with expan valve removed), never compressors or driers. If the system has rear air you need to excite the rear air solenoid valve.

Dye and black light works if you can see the leak; cars with rear air may require pulling things apart.

Today you can source an electronic leak detector new for under $100

There are pro's and con's with nitrogen: cost of the filled tank, an adapter to your refrigerant service set.

firemn131

Thanks Griff.
I really appreciate you taking the time last week to educate me up on the system.
I rebuilt the compressor recently to include nose seal, rebuilt all lines and components flushed with correct flush solvent until it ran out clean.
New exp valve
Dryer and 1 line.
I had trouble with getting the other line off.
So, $$ started to run out and I decided to push forward without rebuilding all lines.

I will do the dye test when I can back off of travel.

When I took everything apart and cleaned it the only place where there was evidence of past leakage was at dryer and on top of the manifold on compressor.

we will see.

J