55.2-59 New AC (small leak)

[FAKKY]

So I get it all together and pull a 30 inch vaccum. Huge leak out of my low side connector ---- so I remove it and go again just measuring from high side.

Still a VERY small leak. Like from 30" vaccum to 10" in around 20 minutes.

Any ideas how to chase down without having to dye it and run it through as AC and truck wiring not done.

Was thinking about running compressed air and soap. I know your not meant to do this on a system that has had refrigerant in it ....... but since this is all new hoses and condenser/drier etc ..... ok ?

Or another other way ? No access to nitrogen.

[mikebte]

Originally Posted by FAKKY

So I get it all together and pull a 30 inch vaccum. Huge leak out of my low side connector ---- so I remove it and go again just measuring from high side.

Still a VERY small leak. Like from 30" vaccum to 10" in around 20 minutes.

Any ideas how to chase down without having to dye it and run it through as AC and truck wiring not done.

Was thinking about running compressed air and soap. I know your not meant to do this on a system that has had refrigerant in it ....... but since this is all new hoses and condenser/drier etc ..... ok ?

Or another other way ? No access to nitrogen.

You could used compressed air and soap. I always used nitrogen and soap and would come up with something. Should not matter as long as it's clean and you give it a good vacuum before charging.

[mr48chev]

I used to assemble ac units back together and stick the vacuum pump on them after my boss had worked his magic on them and there is an accepted time period for them to hold a vacuum after you shut the pump off. That was mid 70's when I was going to college in the morning and working for Tommy in the afternoons though.

These guys are saying it should hold for about 15 minutes. https://www.2carpros.com/articles/re...itioner-system

Did you let it pump down for a full 30 minutes before you shut the valves and turned the pump off? It has to pump that long for the vacuum to get the moisture out. You don't accomplish the task correctly if you just let it pump for a few minutes and then turn it off.

[FAKKY]

Originally Posted by mr48chev

I used to assemble ac units back together and stick the vacuum pump on them after my boss had worked his magic on them and there is an accepted time period for them to hold a vacuum after you shut the pump off. That was mid 70's when I was going to college in the morning and working for Tommy in the afternoons though.

These guys are saying it should hold for about 15 minutes. https://www.2carpros.com/articles/re...itioner-system

Did you let it pump down for a full 30 minutes before you shut the valves and turned the pump off? It has to pump that long for the vacuum to get the moisture out. You don't accomplish the task correctly if you just let it pump for a few minutes and then turn it off.

I pulled the vacuum for close to an hour (eating dinner).
Im not sure I shut the valves though ...... think I just turned off the vacuum.
Its a really old gauge an vaccum set I had from like 8 years back sitting in storage ....

[mr48chev]

I'd just try it again and make sure I did shut the valves off and see what goes.

[jbarron]

Don't full yourself.
You have a leak.

Compressed air and soap it.

[FAKKY]

Originally Posted by mr48chev

I'd just try it again and make sure I did shut the valves off and see what goes.

Did this this morning.
It seems slower ...... it might take 30 mins to go from 28 back to 0 ...... but seems to still be there.
Hard part is I dont trust my chinese gauges/manifold thats been in storage for 8 years - meaning that the leak is not from that.

Think Im going to have to compress air it.

[FAKKY]

Originally Posted by jbarron

Don't full yourself.
You have a leak.

Compressed air and soap it.

Right. Think no choice.

Was just these articles ......

https://www.tirebusiness.com/article...c-system-leaks

[Kevin Mac]

I would not advise using compressed air, it is a new system with a drier, the compressed air will have moisture and other contaminates in your new system. I would use nitrogen for sure. Do you have a buddy in the heating/cooling business or a plumber buddy, they might have a tank of nitrogen. A micron gauge used with your vac pump will tell you if you have a leak also but I know if you don't have access to nitrogen a micron gauge is probably out of the question. If so get the micron gauge below 500. In the commercial HVAC world nitrogen for pressure testing for leaks is the norm, never used compressed air.
Mac

[qbeanie]

Try a can of R134a dye charge and then use a black light to check for leaks. Save for new systems.
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[FAKKY]

It was a 50/50 split on yay/nay ..... and since I figured all the components have been open to atmospheric air at least for an hour or more during assembly ..... to hell with it.

Toook about 5 mins to find the leak.



Was a cheap ebay firewall fitting that wasnt flush with my ac fittings ..... and I knew that based on having to lightly sand the other side ..... but obviously didnt think about it on this side.

Will vaccum for a few hours (~4) and then lit sit overnight .... check in morning.

[mikebte]

Originally Posted by FAKKY

It was a 50/50 split on yay/nay ..... and since I figured all the components have been open to atmospheric air at least for an hour or more during assembly ..... to hell with it.

Toook about 5 mins to find the leak.



Was a cheap ebay firewall fitting that wasnt flush with my ac fittings ..... and I knew that based on having to lightly sand the other side ..... but obviously didnt think about it on this side.

Will vaccum for a few hours (~4) and then lit sit overnight .... check in morning.

Dang, I got them same fittings. I'll have to remember your experience come time to hook mine up.

[Kevin Mac]

Glad you found it, I hate leaks and A/C is one of the worst!
Mac

[FAKKY]

right on.
Held vacuum without loss all through the night.
Good deal.

Thanks all.