Non-working AC thread #3141592

[ganun]

+1 on CABMANDO

[Bob Kontak]

Originally Posted by cabmando

I have a suggestion, throw some refrigerant in it and drive the car. When you have it gassed up, look for refrigerant oil that is a telltale sign of a leak or a proximity of where the leak is. Rather than removing every part and replacing, find the leak, fix it and move on. If you can't find oil, go get a R134 leak detector and sniff out the problem. You could replace seals and still not fix the leak because it could be on the coil end
s of the evaporator or condensers at the front and rear.

OP has green dye in his system. Leak(s) will be evident when he pulls hoses, etc.

Also, most likely R12 oil mix issues with R134 oil.

[cabmandone]

Originally Posted by Bob Kontak

OP has green dye in his system. Leak(s) will be evident when he pulls hoses, etc.

I get that, but rather than make him chase his tail, why not charge the system, run it and either use a leak detector (my guess it's a rent item at autozone) or a UV light to find the leak rather than tearing the thing apart and throwing seals at something that might not need seals?

He could replace all the seals and find it was his schrader valve at the line tap that is leaking. I've had that happen more times than even want to think about.

[Bob Kontak]

Originally Posted by cabmando

I get that, but rather than make him chase his tail, why not charge the system, run it and either use a leak detector (my guess it's a rent item at autozone) or a UV light to find the leak rather than tearing the thing apart and throwing seals at something that might not need seals?

He could replace all the seals and find it was his schrader valve at the line tap that is leaking. I've had that happen more times than even want to think about.

Your procedure is what I would do.

However, below is the 2nd picture of post #1. This was the basis for the suggested open and clean out. The grunge inside the drier.

[Pato911]

Too late. I opened it up and cannot see any evidence of leaks so far. I can try pressure testing.



I have ordered a new drier and TXV from PP. Since it is already open and the parts are ordered, I am going to replace those bits and lean toward doing the hoses as well. Are you guys recommending leaving the original hoses?

Of course, while down there, I got to poking at some rusty drain holes and it appears my front pan between the A-Arm mounts is rusted. Solid at the mounts and soft across the middle. It seems solid above the condenser.

Based on the likely need to repair this sooner rather than later, should I pull the hoses and leave it out for the repair? I would love to do this myself but do not have a lift and haven't done MIG welding in over 10 years.

[ganun]

Pan doesn't look that bad.....take a look where the hoses come out over the driver side front bumper shock, the way the factory routed the hoses leads to build up of crud there and promotes rust.
Reroute the hoses if you can.
If you can do new hoses by all means, new barrier hoses have a smaller OD.

[Bob Kontak]

Originally Posted by ganun

If you can do new hoses by all means, new barrier hoses have a smaller OD.

+1

With the work you are putting into it, definitely

Thinking back to what cabmando said, replace the schrader valve thingies regardless of whether they look fine. I have had at least two jobs - across my wide array of maybe 15 - that those suckers leaked,

You need to check out the front condenser as well for leaks.

Congratulations for getting in there. It's just grunt work for the most part.

[Pato911]

Update: Everything is out. The condensers and evaporator do not look like they have been leaking so my best bet for now is the hoses, o-ring connections and the schraeder valves Cabmando suggested.

I will replace hoses, TXV and drier. I am also considering a new front condenser from Kuehl.

I am very concerned about the rust but will search the forum and, probably, start a new thread.

Once the AC work is done, I will be sure to update the thread on outcome as it frustrates me to see these things linger without closure.

[ganun]

Not sure about how much bang for the buck from a new front cond.

[wwest]

Originally Posted by ganun

Not sure about how much bang for the buck from a new front cond.

Might even be a negative, most aftermarket front lip condensers appear to have significantly improved efficiency with vertical, blower forced airflow, but below factory efficiency "underway", front to back airflow due to roadspeed.

Factory condenser cooling vanes are "open" to airflow in both cases.

[Bob Kontak]

Originally Posted by wwest

Might even be a negative, most aftermarket front lip condensers appear to have significantly improved efficiency with vertical, blower forced airflow, but below factory efficiency "underway", front to back airflow due to roadspeed.

Factory condenser cooling vanes are "open" to airflow in both cases.

I would think only replace if leaking. Right now you need a functioning system.

Clean it out and get it up to snuff with the basic replacement parts discussed. Hoses at your discretion.

Upgrade once you can hold a charge. :-)

Bummer you did not pick up the green stuff as evidence of a leak. Seems odd. given you have stripped it to the nub.

[Pato911]

Hey everyone! It has taken a while to get back to you on this but I plead extenuating circumstances.

Went to Brazil for World Cup:


Fixed rusty front clip:


And, of course, work (no photos of that).

Finally, I got back to the car. I replaced hoses (Rennaire), Drier (Pelican) and rear condenser (ACKits).


I borrowed a vacuum pump and gauge set from Autozone and evacuated the system for a couple hours then charged it using 4 small cans. 100F ambient and I got the vent temp to 70F. I need to add more (250/ 30#) but ran out of R134. I may take it to a pro and have it loaded professionally.

One thing that bugged me was the low side port appears to have a small leak. I turned off the car and unplugged the gauges and heard a slight hiss. I tightened the schrader using a tool from my bike kit and it stopped making noise but I checked an hour later and there was pressure under the cap. Do I need to evacuate and replace the valve?

[Pato911]

I just reread the above and to clarify, I did replace the low side schrader before install. So, maybe it was leaking before and now again/ still? What is the failure rate/ percent on these? I also added a high pressure switch to the high side (which was combined with a new high side port). No leak there...

[DaveMcKenz]

I have heard of a Shrader valve core tool that can be used on a fully charged system.
Also 4 cans of R134 seems like a lot unless you are wasting quite a bit. My 84 with front condenser only required 23 oz. or two cans. What kind of temp and pressures are you running?
Good luck,
Dave

[Ronnie's.930]

^^^ He said in post #72 above that he was getting 70 degree vent temps in 100 ambient (very poor performance, in other words).

[Pato911]

Yeah. Poor performance so far. Needs some more attention. Also mentioned pressures. Roughly 250# hi / 30# low. Probably take to a pro for charging as I feel a bit lost.

[Pato911]

Also, the 70deg vent temp was with doors open so no recirc of cooled air. It can likely be improved but a 30deg drop is a decent start.

[Ronnie's.930]

Originally Posted by Pato911

Also, the 70deg vent temp was with doors open so no recirc of cooled air. It can likely be improved but a 30deg drop is a decent start.

Pato, I didn't mean to sound offensive with my "poor performance" comment, but 70 degree air at the vents is indeed very weak (70 degree cabin temps, when 100 ambient, would be good, but not 70 at the vents). Also, the 250 high side pressure is too high - probably the result of overcharging since you mentioned adding 4 cans of refrigerant (210-220 would be better).

By way of comparison, I'm getting vent temps of 29-30 degrees with ambient of 98, and have 30 low and 210 high side pressures. I'm sure there are other differences in our systems, however. Regardless, you are obviously making progress with it.

One other thing I wanted to mention is that if you decide to work on this further, as opposed to taking it to a shop, I would be more than happy to discuss the evac, charging process, etc. with you (you being a fellow TexASS resident and all ) on the phone.

[DaveMcKenz]

Originally Posted by Pato911

Yeah. Poor performance so far. Needs some more attention. Also mentioned pressures. Roughly 250# hi / 30# low. Probably take to a pro for charging as I feel a bit lost.

I see. I missed the pressures. No that's not really all that bad. It does sound slightly overcharged. If you got down to 25#/210-225# you would probably be doing fine. But for 100 F. ambient, not a bad start.
Good luck,
Dave

[wwest]

Originally Posted by DaveMcKenz

I see. I missed the pressures. No that's not really all that bad. It does sound slightly overcharged. If you got down to 25#/210-225# you would probably be doing fine. But for 100 F. ambient, not a bad start.
Good luck,
Dave

Unless the windows and/or doors are wide open ambient might have little to do with vent outflow temperatures. The parameters that matter are cabin temperatures at/near the passenger footwell and the vent outflow temperature.