Originally Posted by jeepchick1013
i tried to charged my ac but the gauge on the hole kept going in the red. so i took it to a shop had the system evacuated and dye injected to find a leak. no leak found. its been about a month and its not cold anymore again. took it back to the shop and they said there was no leak and it could be behind the dash. but theres no smell so i dont see how it could be behind the dash. any ideas?
If your evaporator is leaking (probably is) and you have dye in your system then the shop should have checked the HVAC box drain (passenger side firewall underneath the cannister) for the dye. The refrigerant/dye will mix with water formed on the evaporator and make its way to the drain.
You or your shop also need to check if one or both of the Schrader valves are leaking. They are the valves under the caps for the low and high pressure side of the system. They are often over looked and very often leak on older vehicles. They can sometimes be tightened up a bit and can even be changed without losing the charge (with a specialty tool).
You can buy a decent UV light on the Internet for about $20 and check the drain tube yourself.
Replacing the evaporator is a big job as the whole dash has to come out. I've seen dealer quotes run from $1,000-1,800. I did mine and it took me a whole weekend.