A/C Exploded!

[Denisefwd93]

We have Nitrogen and run the pressure up to a safe pressure ( 2 stage reg) no more then oh, About 300 lbs soap bubbles are still the best hi tech leak detector.

 

[ratdude747]

We have Nitrogen and run the pressure up to a safe pressure ( 2 stage reg) no more then oh, About 300 lbs soap bubbles are still the best hi tech leak detector.

If I had nitrogen I would too. Sadly, I don't.

 

[adsm08]

Don't forget to check the valves. I have had some really elusive leaks at the valves.

One took me three months to find. I never would have found it if I hadn't had to move the vehicle during the vacuum test. Unhooked the line and the valve dropped because the springs were shot.

 

[Denisefwd93]

If I had nitrogen I would too. Sadly, I don't.

Nitrogen is 1500 -2000 psi in the tank. The adjustable 2stage regulator will reduce it to safer pressure. Most automotive ac shops don't even use the method, it's too easy to blow things apart, unlike non mobile systems with very few mechanical connections.

vacuum checking will only show as a leak if it's very large unless you have weeks to wait, not hours.. and then you still won't know where the leak is.

warm hot weather will give you higher pressure on the 134 since refrigerants will always show the pressure that is equal to the ambient temp.

NEVER use compressed air!

 

[ratdude747]

Don't forget to check the valves. I have had some really elusive leaks at the valves.

One took me three months to find. I never would have found it if I hadn't had to move the vehicle during the vacuum test. Unhooked the line and the valve dropped because the springs were shot.

Tried that awhile back. Both are newish... the high side is a year old, the low side is a few weeks old. The high side is missing the cap though... could that be an issue?

 

[ratdude747]

Nitrogen is 1500 -2000 psi in the tank. The adjustable 2stage regulator will reduce it to safer pressure. Most automotive ac shops don't even use the method, it's too easy to blow things apart, unlike non mobile systems with very few mechanical connections.

vacuum checking will only show as a leak if it's very large unless you have weeks to wait, not hours.. and then you still won't know where the leak is.

warm hot weather will give you higher pressure on the 134 since refrigerants will always show the pressure that is equal to the ambient temp.

NEVER use compressed air!

Noted. I don't locally have compressed air even... I know, I suck.

Shame, as my Grandpa owned a HVAC and sheet metal shop; had he been healthier and/or had a son (instead of two daughters) I'd have access to all sorts of pro level equipment. Instead, his health wasn't so good, he got disability, sold the shop, and died of a heart attack when I was five years old. I miss him... Anyway...

 

[ratdude747]

Another possibility:

I noticed that my variable orifice tube started making a different noise around the same time I saw a change.

Before it would make the usual hissing noise (pressure equalizing after shutoff). However, it now makes an awful intermittent buzz/squeal.

Also the past couple days have been cooler.

Could this be something? Or is it a symptom and not the actual problem?

(PS- could a mod move this to a better sub-forum since it's not exactly urgent?)

 

[ratdude747]

First, thanks to whoever moved this.

Anyway, I went ahead and ordered a shaft seal and body O ring kit. The compressor looks to be factory, so it's 22 years old, surely those seals are shot (as were the old pancaked O rings). I know it didn't come with the JY motor the PO installed as in the pile of spare parts he included I found an AC bypass pulley.

From the limited info I found online the noise change does indicate a refrigerant leak (low refrigerant).

What's the trick for removing the clutch screw? Pin wrench for the holes in the clutch plate?

 

[ratdude747]

IDK. Did another test today, according to my thermometer it's working right although the reported temps seem high. It didn't feel 90 out but it says it is. Thus the 60 degrees it reports as a vent temp (full cold, fan to low, no re-circulation) passes. *checks weather report* OK, it really was 90... So yay, may not be a leak after all?

 

[Denisefwd93]

134 has a lag in the low side that 12 never had. So it takes a bit of time and always seems to lag at lower rpm. Generally, the hi should be the equivalent pressure 15-20 degrees above the ambient. (That is found on gauges or on a TP chart, generally again, the lo should be 15-20 degrees lower in equivalent pressure .
Just do a web search for 134A TP CHART
These are ball park guidelines. Automotive systems always seem to run higher

 

[ratdude747]

134 has a lag in the low side that 12 never had. So it takes a bit of time and always seems to lag at lower rpm. Generally, the hi should be the equivalent pressure 15-20 degrees above the ambient. (That is found on gauges or on a TP chart, generally again, the lo should be 15-20 degrees lower in equivalent pressure .
Just do a web search for 134A TP CHART
These are ball park guidelines. Automotive systems always seem to run higher

At which point in the pressure cycle are you speaking? The pressures are not constant...

Tomorrow is supposed to be nice and toasty... that will be a good time to test.

 

[Denisefwd93]

No, the pressures vary with change with ambient temp, compressor rpm, evap fan, condenser fan and air flow and charge (over or under) . Most people who don't want to bother just put a hand of the the low side hose to the comp to "feel" if it's cool to cold, they tell you it's ok.

 

[ratdude747]

well shit.

I redid the compressor seals. The valve pack came apart, but I was able to get it back together and working. The internals looked to be in good shape without any signifigant wear.


However, the AC line going to the compressor died. Somehow I burred/mushroomed the high side of the compressor connection block, and that kept it from sealing. Filing the burr didn't fix it as I think I nicked another part of it. Either way, the line to compressor connection isn't sealing at all, and due to having to buy new tires today, $100 for a new line isn't happening for a while. Looks like I'll be doing a new line and accumulator (as it will saturate between now and any reasonable time I'll get a proper line replacement). Assuming that my shaft seal fix was successful (otherwise I'm looking at $350 in parts which would include a reman/new compressor).

I hate 255 AC... but I'll have to keep using it. Grr...

 

[Doofy]

Yes, I'll bet you are sick and tired of messing with the a/c. Glad my first attempt on the wife's Jeep was a success. We don't really need a/c in Alaska that often but I hate when something on a vehicle doesn't work. It simply needs fixing! Good Luck.

 

[ratdude747]

Yes, I'll bet you are sick and tired of messing with the a/c. Glad my first attempt on the wife's Jeep was a success. We don't really need a/c in Alaska that often but I hate when something on a vehicle doesn't work. It simply needs fixing! Good Luck.

Yeah. The more I think about it the more I think I might as well replace the compressor too, just to be safe. Given how much went wrong during the seal job I have to wonder if I did foul it up. IIRC rockauto has 4 seasons brand compressors for cheap? I thought it was $180 but maybe it's less than that.