99 Ram A/C

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kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

99 Ram A/C

Post by kevm14 »

I noticed the Ram engaged its A/C compressor one day for a second. So I figured the charge hadn't all leaked out if there was enough for the low pressure switch to close.

I put in 2, uh, 12oz cans and a 4oz stop leak/dye. It seemed to work. Then it didn't. Turns out the clutch wasn't really sucking in properly. I bent and tweaked around with it several times and I think I was finally successful. I went on a test drive and it worked the whole time. It was like 58F outside so the real test will be warmer weather but I think I have functional A/C now.

Funny thing is I am actually quite familiar with this problem. I saw it on a similar era Dakota. But also on my Caprice. The Caprice gets the most leeway as that compressor is original at 311k so the wear just opened up the gap too much until I tweaked it. It is just an electromagnet that sucks the rotor against the spinning pulley.

Oh, it also happened on the Ranger. Beats replacing the compressor or clutch.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: 99 Ram A/C

Post by kevm14 »

Been long enough that I thought I would update this thread.

A/C is still working. I don't know if it is working 100%, but it is working. We are approaching 2 months. If it makes it 2 full months, without needing more refrigerant, I would be unlikely to chase down a leak unless it was really obvious (or easy to fix). So far, no indication of a leak, but I have to believe it leaks - I just don't know the severity.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: 99 Ram A/C

Post by kevm14 »

I used it again today. Humid out, not particularly hot. But it really seems very effective. I also drove my Caprice today and I will admit that the Ram's A/C appears to perform significantly better. The Caprice has two large issues which the Ram, critically, does well at for both:

1) Airflow. The Caprice has always been airflow challenged but it may be worse lately. It seems like the evaporator is probably partly plugged with debris, which shouldn't be that surprising for 312k. I probably need to pull the fan and vacuum at least which has helped in the past. But I bet that evaporator looks nasty. The Ram, by comparison, blows a lot of air on high, as it should.

2) The above one compounds this one sadly. The low pressure side hysteresis for switching the clutch back on is too wide. I am using an aftermarket refrigerant concoction and would probably be better off with R134a. The Ram, by comparison, does a great job of engaging the compressor clutch much sooner after the pressure starts to rise after disengaging. This keeps vent temps cool. On the Caprice, vent temps fluctuate pretty wildly with the cycles. And the lower airflow over the evaporator means the clutch will be cycling that much more often. The result is not great A/C cooling capacity. Ironically it works better in hotter weather as the clutch stays engaged more often. On a day like today with mid 70s but humid air, it is kind of at its worst.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: 99 Ram A/C

Post by kevm14 »

I think it is finally getting due for another can.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: 99 Ram A/C

Post by kevm14 »

Added a can. That may have been more than it needed but with a slow leak, meh. Almost 2.5 months and it is not like it completely stopped working, either.
Fast_Ed
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Re: 99 Ram A/C

Post by Fast_Ed »

Since you're in this mode anyways, have you considered 'stop leak?' I mean.. it couldn't hurt.

The Saturn goes over a year on a charge. But the compressor does make a whining noise when it is engaged. I'll probably wait for it to explode completely before doing something.
kevm14
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Joined: Wed Oct 23, 2013 10:28 pm

Re: 99 Ram A/C

Post by kevm14 »

I did.
kevm14 wrote:I put in 2, uh, 12oz cans and a 4oz stop leak/dye. It seemed to work.
kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

Re: 99 Ram A/C

Post by kevm14 »

Decided to see if Ed's new refrigerant sniffer found anything on the Ram for leaks. It found nothing in the engine bay. But it did find something in the vents. I made a video because it was interesting and also something you could really only do with a sniffer.

https://youtu.be/qCW9lDNvAE8

Options are:
1) Continue to do nothing and add cans as needed
2) Try some more stop leak
3) Replace evaporator
kevm14
Posts: 15200
Joined: Wed Oct 23, 2013 10:28 pm

Re: 99 Ram A/C

Post by kevm14 »

Here is where the evaporator lines enter the firewall. I would assume O-rings on these connections and none inside. So a leak inside is 100% the evaporator core itself.
20190601_102433.jpg
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