Help with rear ac block off.

[2009Caraman]

I have a rear line leak in my minivan. A rear ac block off kit is a simple remedy to this otherwise expensive repair. My problem is that right now my ac lines are 1/2 filled with hydrocarbons. In canada we can't buy r134 so most popular ac refill from can is r12a.

I can't get this evacuated easily. I visited a mechanic & they won't do it with their machine. If i cut those lines will all refrigerant escape? Likely yes but will there still be traces of r12 that vacuum machines can read after the block off is installed?

 

[atikovi]

Originally Posted by 2009Caraman
My problem is that right now my ac lines are 1/2 filled with hydrocarbons. In canada we can't buy r134 so most popular ac refill from can is r12a.


Can't you just press in the schrader valve to vent it out?

 

[sloinker]

What year is the van? R134 has been the factory fill for years. R12A is only available in the states to license holders. If you have a leak I am thinking that pretty much all the refrigerant is gone as the front and rear share the refrigerant.

 

[2009Caraman]

The van is 2009. Original refrigerant was r134 but now it's 50% r12a. Was put in the system last year without understanding the consequences. We can't get r134 in canada for private sale.

Was leak tested today. Rear lines and expansion valve have a slow leak.


I guess my question is if there would be a trace of the r12a if it was accidentally vented. It's hard to find mechanics who will recharge once that stuff has been put in a system.

 

[928]

Flush entire system with a/c flush, find & fix leak. Test with nitrogen. Add correct oil for the refrigerant you are using (r12 & r135 use different oil) do it once , do it right

 

[atikovi]

Just so everyone understands, he has R12a not R12 in the system.

 

[WobblyElvis]

R134a has not been a restricted substance for a few years in Canada. It is illegal to service an AC system without the appropriate license but it is not illegal to possess it or sell it. Venting it, unnecessarily, into the atmosphere is also illegal but that's where most of it goes. Auto parts stores do not want to step into a grey area and sell it over the counter however you can buy it in electronic shops where it is sold as dust off or cool shot or gum remover for carpets. The nozzle is not compatible with an R134 tap but you can use a "saddle/band clamp".
This doesn't help you with the vacuum or refrigerant oil problem.

 

[Chris142]

Most refrigerants boil @ -40f or so. If you have a leak anywhere it will all leak out .

 

[sloinker]

If you have an air compressor you can buy a line set and vacuum device from harbor freight and boil down your system after capping the rear lines. The line set will show the vacuum applied, let it run at a vacuum for a couple hours. Then test if it maintains vacuum for an hour. Lastly, buy the replacement refrigerant that already has the oil in it. Since you have had two differing kinds of refrigerant/oil there will be vestiges of some non compatible oil left over. Short of a complete system cleaning with alcohol or another solvent/cleaner, you will just have to live with the results and hope for the best.

 

[2009Caraman]

Tha
Originally Posted by sloinker
If you have an air compressor you can buy a line set and vacuum device from harbor freight and boil down your system after capping the rear lines. The line set will show the vacuum applied, let it run at a vacuum for a couple hours. Then test if it maintains vacuum for an hour. Lastly, buy the replacement refrigerant that already has the oil in it. Since you have had two differing kinds of refrigerant/oil there will be vestiges of some non compatible oil left over. Short of a complete system cleaning with alcohol or another solvent/cleaner, you will just have to live with the results and hope for the best.



Thank you. This be the kind of info I was looking for. I was hoping to get it vacuumed at a service station but that could be tricky. I'll buy a vacuum pup and twin manifold gauge combo and attempt it myself. Price is similar to a standard evac/recovery and fill anyhow.

 

[sloinker]

There should be a decal under the hood that indicates the amount of refrigerant required for a single or dual system. You will use the single system amount as a general guide and the line set gauges to get the proper fill.

 

[JTK]

Originally Posted by Chris142
Most refrigerants boil @ -40f or so. If you have a leak anywhere it will all leak out .


That's my thoughts too.

If you have a leak of any magnitude and she's not blowing cold, what ever mix of refrigerant you had in there is long gone. Doesn't matter what you had in there provided it was a refrigerant.