Automotive Air Conditioning Information Forum

AC blowing warm air
It's been a while since I used my AC but I was blowing hot air.

I've fixed many AC systems on old Chevrolet cars that used R12 and understand the fundamentals. My NSX is a 95 and has r134.

My questions:

1) should I simply try adding more r134 and see what happens while monitoring low side pressure?
2) do I need to jump the low pressure switch to add it?
3) should I simply follow the standard r134 temp vs pressure curves?

Or

4) should I pump the system down and start fresh adding the proper r134 by weight?

Ed

Recover & charge by weight. Then you can evaluate system performance.

It probably has a leak I would add dye when recharging, and inspect everything after running the system for an hour or more.

Edited to add:
That system is tiny. Really easy to overcharge, and "topping up" can go from not enough to too much pretty quick. Use a scale.

bohica2xo wrote:Recover & charge by weight. Then you can evaluate system performance.

It probably has a leak I would add dye when recharging, and inspect everything after running the system for an hour or more.

Proper advice, I'll second this method.

Thanks!! I'll pull a vacuum this weekend and see if it holds. Then if it does, I'll add the recommended amount of r134 using a scale.

I'll keep you posted.

Thanks!
Ed

System can hold a vacuum and still have a leak. Dye is your friend.

Got it. Will add dye as well.

Ed