95 Chevy G20

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Gladiator
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95 Chevy G20

Postby Gladiator » Sat May 27, 2017 10:43 am

I'm currently restoring my late Grandpa's Chevy conversion van that I recently found and bought back.

I found the rear a/c drier was rusted out and leaking r134, so I ordered a replacement, I broke both metal hose fittings in the process of removing the old drier, although they were probably due for replacement anyways from how rusty they were. I cut the old metal fittings off the rubber hose and found new ones at Napa along with new o-rings, now I'm trying to find a repair shop with the proper beadlock crimp tool but so far nobody seems to have one.

What I wanted to find out was, at the front of van, the fitting on rear high pres. hose does not appear to have an o-ring and I was wondering on this style of connection, should it have an o-ring or is it likely a washer style seal?

Where the rear a/c hose connects at the front:

Image

Front fitting of rear a/c hose:

Image

Old and new drier comparison:

Image
GM Tech
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Re: 95 Chevy G20

Postby GM Tech » Sat May 27, 2017 6:21 pm

The connection you have pictured is the "upfitters" connection- the panel van came from the factory with front air only and a dead-head connection for the "upfitter's" conection to screw into. You see, the factory sold the panel van to an "Upfitter" or conversion company- the upfitter will dress the plain panel van- cut holes for the windows, add the captains chairs, put in all the fancy interior lights, and the speaker system- as well as the duct work and rear evaporator and associated lines.. The photo shows the piercing mechanism that when the upfitter installs the rear system, he need to only pull a vacuum on the rear lines, and then screw the connection together where it automatically pierces the internal dead head, and now there is flow to and from the rear system- all this is done so as not to have to discharge the original front a/c only system. So, is there not an internal seal (rubber element) inside the upfitter connection? Your photo looks like it is there- very similar to "gator grips" internal rubber o-rings found in the water plumbing industry..
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Gladiator
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Re: 95 Chevy G20

Postby Gladiator » Sat May 27, 2017 11:47 pm

It's a little difficult to tell, maybe it's a rubber bonded metal washer, I just wanted to make sure it didn't need a green o ring like the back fittings needed.

I was wondering if it would be necessary to remove the hoses to be crimped or do you think a shop would be able to fit the crimping tool underneath the van to crimp them, it's not going to be easy to remove the hose that goes to the rear a/c unit from the rear drier.
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Gladiator
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Re: 95 Chevy G20

Postby Gladiator » Wed Jun 07, 2017 6:56 pm

Luckily a family friend with a repair shop loaned me his hose crimping tool and I got it all hooked back up.

I'm going to have a shop do a vac and fill, but because I used uv dye to find the leak, do I need to worry about flushing the system?
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Cusser
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Re: 95 Chevy G20

Postby Cusser » Wed Jun 07, 2017 9:35 pm

UV dye is fine to stay in the system, a good thing. Some manufacturers add it during the build.
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Gladiator
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Re: 95 Chevy G20

Postby Gladiator » Fri Jun 09, 2017 12:23 pm

Great, thanks for the info.

I had a vac and fill done today for $59, which turned into $91 as the fine print said for only up to 1lb r134.

They filled it up to 3 lb according to the factory sticker but I believe because of the upfitters rear a/c added on it's a little over a pound low as the front cools great but the rear not so much.

They said they put in the proper amount of oil but the newish compressor is very noisy.

My question is, when I shop for a r134 can to fill up the rest of the system, should it contain oil or pure r134, as I'm not sure if it's based on percentage of oil to r134 or just a set amount of oil.
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Gladiator
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Re: 95 Chevy G20

Postby Gladiator » Sun Jun 11, 2017 5:07 pm

I'm having problems optimizing the pressures while I'm trying to fix the mistake the repair shop made in that they only filled up r134 enough for the front system not including the rear. I'm trying to get the low to at least 45 psi as it's 90 degrees out but I feel like I'm having to put in too many cans of r134 for barely any increase in the gauge. Hooking up the gauge to the rear low side service port yields the same reading as the front.

Between me and the shop we've put in almost 90 oz and this is what I'm currently sitting at pressure wise at 90 degrees ambient. The front cools good but the back feels like it's barely trying.
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bohica2xo
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Re: 95 Chevy G20

Postby bohica2xo » Mon Jun 12, 2017 7:00 am

If the system has two dryers, it will hold quite a bit. Are those pressures at idle?

With those pressures you should have cooling. There is no reason to see a higher low side pressure.

If the rear system is not cooling, then the TXV is the place to look.
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Gladiator
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Re: 95 Chevy G20

Postby Gladiator » Mon Jun 12, 2017 7:14 am

Yes at idle, my dad says the high pressure shot up as I revved it a bit. The front vents are around 45f, the rear is around 60f.

My biggest concern right now is that the compressor which was replaced sometime last year before I bought the van, sounds like a mini jack hammer, I'm worried there is too much/ or not enough oil in the system. The shop says they did add some.

https://www.youtube.com/watch?v=-sTLXBnVoUw
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bohica2xo
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Re: 95 Chevy G20

Postby bohica2xo » Mon Jun 12, 2017 7:28 pm

Gladiator wrote:Yes at idle, my dad says the high pressure shot up as I revved it a bit.



That is an indication that you are either overcharged or have a condenser problem.

When you start adding refrigerant trying to hit an arbitrary pressure you can put way too much refrigerant in. 45 psi on the low side is actually a bit high for good performance - the P/T chart says 49f for 134a liquid.

The high side spike will not be good for the compressor. You have an HD6 compressor - not the most robust model. It does sound loud, does that noise stop with the A/C off?

The shop added "some oil" - how much & what weight?

Probably time to recover that charge & start over. I would pull the TXV for the rear system & see if it is plugged with debris.

Perhaps GM Tech can chime in on that compressor noise?

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