Vintage Air Evaporator Leak Test

[jks67ss396]

Guys

Is there anything i can do to test the evaporator for leaks before having my system charged for the first time? Ive heard some guys pressurize the system with compressed air. I know that introduces moisture, but the thing will be vacuumed out when its charged anyway.

i just want to test the evaporator so i minimize the chances of having to pull it out once the system is charged (ie slow leak or something)

Any ideas?

thanks!

[engineer_gregh]

I'm not sure but I would think a vacuum test would accomplish the task. Question is, can you do a vacuum test on just the evaporator? I'll refer to smarter people than myself.

[screaminchevypickup]

When you loosen the caps if it relieves pressure you want have any leaks..

[BMERDOC]

We use nitrogen for diagnosis. The shop will put a vacuum on the system before charging it so if they have any sense they'll pause before charging to make sure the system is leak free.

[jks67ss396]

Hey screaminchevypickup (i bought it from Sarah)

I really want to test the lines that screw into the evap. they seal with o-rings. thats what i want to test... pain in the butt to pull it back out or expensive if the shop does it

Nick or anyone else,

I have hoses that screw into the evap that are unterminated on the other end. so maybe hose clamps to compressor hardline??

Is there anything wrong with using compressed air if i get it evacuated later???

thanks!!

[Ol Blue K20]

Most shops vacuum it and wait to make sure it'll hold a vacuum. If it won't hold vacuum it won't hold pressure.

[mcbassin]

I like to pressure the system with Nitrogen up to 100-150 psi. I wouldn't recommend using compressed air if you can avoid it. It will have moisture in it.
Then pull a hard vacuum for a few hours. I use a digital manometer to see if it holds vacuum before charging with Freon.

I would be willing to bet Vintage air already did a pressure test with nitrogen.

[fattyarbuckle]

vacuum to 500 micron, isolate system with pump shut off, if it holds there for 24hrs, there isn't a leak or moisture...

I've never heard of a manometer for vacuum.

[BMERDOC]

We use Manometers to check crankcase vacuum. BMWs run negative crankcase ventilation.

[screaminchevypickup]

Originally Posted by jks67ss396

Hey screaminchevypickup (i bought it from Sarah)

I really want to test the lines that screw into the evap. they seal with o-rings. thats what i want to test... pain in the butt to pull it back out or expensive if the shop does it

Nick or anyone else,

I have hoses that screw into the evap that are unterminated on the other end. so maybe hose clamps to compressor hardline??

Is there anything wrong with using compressed air if i get it evacuated later???

thanks!!

Every unit comes pre tested.. I wouldn't put any air in the system because like others have said you will get moisture... I've never had to pull vacuum on one of these system for more than 30 minutes..

Also thanks for the business..

Kyle

[fattyarbuckle]

LOL^^^

Manometer can't check inch's of vacuum...they can only check a negative or less than atmosphere pressure.

[mcbassin]

Originally Posted by fattyarbuckle

LOL^^^

Manometer can't check inch's of vacuum...they can only check a negative or less than atmosphere pressure.

Not sure what this means? I routinely use a very low vacuum chamber for aerospace work. To monitor differential pressure we use a manometer. If you can hold negative sustained pressure. After the pump is turned off, You won't have a leak. It's a simple tool to monitor pressure. Did I miss the joke?

I use my gauge set for reading vacuum pressure.

[jks67ss396]

Originally Posted by screaminchevypickup

Every unit comes pre tested.. I wouldn't put any air in the system because like others have said you will get moisture... I've never had to pull vacuum on one of these system for more than 30 minutes..

Also thanks for the business..

Kyle

Hey Kyle

Buying from you was a no-brainer. best price by far!

But, getting back to this, i understand the evap as a unit might have been tested at factory, but i put the lines on at home, and seald with o-rings.

thats what i want to test. if the orings sealed properly.

by the sound of it, ill need some fancy equipment if i cant use an air compressor, and i might as well pony up and let the shop test it. worse case, i have to pull the evap box right there at the shop and fix whats needed.

thanks!

[MARKDTN]

I have always used compressed air. If you have a dryer on your compressor and pull a good vacuum you should not leave any moisture when you are done. I just put 100 psi into both sides, close the valves, and let it sit 20-30 minutes. If the needles stay put I let it out (slowly so you don't loose any oil) and pull a vacuum for 45 minutes or so and I have never had any issues. If you have access to nitrogen I'm sure that would be even better, but a good longer-than-usual vacuum should get all the moisture. A compromise might be to pressurize with shop air with an old dryer to check for leaks and change it before the vacuum and charge since the dryer media is where moisture can be captured. Then you only have 2 fittings to worry about. Won't help with your situation, but may help someone with a stock system.