Heater Core and Evaporator Testing

[MONC440]

I need to leak test my heater core and evaporator. They are still in the car but not hooked up. I don't wat to remove them if they are good. Any thoughts on the best way to test them? I was thinking of rigging up a vacuum gauge and pulling them down to say 30 inches and let it sit over night. My other thought was to pressurize with compressed air (15 psi in the heater core, and 100 psi in the evap) and letting it sit overnight.

Any thoughts?

Thanks

 

[Big_John]

I think using vacuum to check the evaporator and pressure to check the heater core might be the best.

I have seen where some AC components, like hoses, won't leak under vacuum, but leak under pressure. I think that won't be an issue with the evaporator. I've also been warned about using shop air to pressure check AC as it tends to be a little "dirty". Shops use nitrogen to check pressure.

As far as the heater core, yea, if it didn't hold a vacuum, you could figure it leaks, and atmospheric pressure is ~14psi. IMHO pulling a vacuum might suck some left over crap and liquid into your vacuum pump.

Really either will work.

 

[MONC440]

I think using vacuum to check the evaporator and pressure to check the heater core might be the best.

I have seen where some AC components, like hoses, won't leak under vacuum, but leak under pressure. I think that won't be an issue with the evaporator. I've also been warned about using shop air to pressure check AC as it tends to be a little "dirty". Shops use nitrogen to check pressure.

As far as the heater core, yea, if it didn't hold a vacuum, you could figure it leaks, and atmospheric pressure is ~14psi. IMHO pulling a vacuum might suck some left over crap and liquid into your vacuum pump.

Really either will work.

Thanks for the good advice.