Since the neon is essentially built around the hvac system, id like to bench test them prior to re installing the dash. I have normal tools, a portaband, plasma, and welder. No vacuum pump or anything. Do have a mityvac and smoke machine though.
So, hows the best way to do this without specialized hvac tools? I know that theres still a chance that they test good but are bad, and id like to minimize the risk if at all possible. And its a challenge car, so new isn't realistic.
Calling Seth.........
In reply to Dusterbd13-michael (Forum Supporter) :
Could you bolt the whole system up on the bench? Compressor, condenser, evaporator, dryer, lines, orifice tube, the whole nine. Then you can see if it will hold a vacuum. And/or use the gauge manifold to pressurize the system with compressed air and then use a bottle of soapy wodder to look for leaks.
The systems are usually tested using vacuum pump and letting it sit with gauges attached to watch for leakage, but my hand hurts just thinking about trying to use a Mityvac to pull vacuum in a system that large...
You can pull a vacuum with an old refrigerator or window AC compressor. Harbor freight sells a real vacuum pump for ~$75 after coupon. You will need one if you plan on recharging the system anyway
I honestly didn't think about hooking it all up on the bench and pressurizing the system and using soapy water to check. Thats awesome. What is the trick to this going to be other than space?
How about heater core? Same way?
In reply to Dusterbd13-michael (Forum Supporter) :
Not pressure - vacuum. Set it up with a vacuum gauge with a port and seal everything else. then pull vacuum on the system or component. Note the vacuum gauge position and let it sit for awhile (like a day or so). If you come back and the needle hasn't moved, you know there aren't any leaks.
Pressurizing a system is tricky - go to far and stuff breaks. Many of the components weren't designed for a lot of PSI. Especially A/C where there is a high pressure and a low pressure side. Enough pressure to test the high pressure side risks the low pressure components. Vacuum is more universal. All of the modern car service manuals I have also specify the cooling systems to be tested with vacuum, not pressure.
Bolt it all up with new o-rings. pump in a can of the freon with leak detector and let it sit for a week. I think it is a UV dye and it comes with the kit.
If you plan to bring the AC to life on your own once installed. you are going to need a vacuum pump. Need to get the air out before the refrigerant goes in.
For the heater core, would you be able to pressurize it to whatever your radiator cap goes to, and submerge it in water to look for leaks? I think that’s what I saw done for a radiator on a recent skid factory episode.
old_ said:You can pull a vacuum with an old refrigerator or window AC compressor. Harbor freight sells a real vacuum pump for ~$75 after coupon. You will need one if you plan on recharging the system anyway
I agree, the HF electric vacuum pump is the right choice here.
The evaporator is under pressure. Common issues with evaporator cores are flow restriction internally and externally and leaking. I would pressurize the evaporator to about 30-40 psi and look for leaks, make sure the exterior is clean, and make sure they flow well internally, Or you buy a new one for cheap online.
The heater core is also under pressure. You can pressurize it slightly and look for leaks, make sure its clean, and flush the inside (in both directions). I used CLR internally for a few minutes on the last one and it worked great. Note: CLR can damage the heater core. I used it as a last resort and had already given in to pulling the dash if I ruined it or it didnt work so nothing to lose in my case.
eastsideTim said:For the heater core, would you be able to pressurize it to whatever your radiator cap goes to, and submerge it in water to look for leaks? I think that’s what I saw done for a radiator on a recent skid factory episode.
Yes ep3 of the MR2. They did an evap core too.
The important bit of info was "metered air".
Shouldn't be too hard to plug the core, pressurize it to 10 to 14psi, submerge it, and let it sit.
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