AC blowing hot Air + hissing noise (HELP)

[05YukonDenaliXL]

Friends,
I just replaced by evaporator last weekend. Finally got to charge the AC with freon this morning. But I am having no luck. The AC blows HOT air, with the clutch engaged. I added more freon but now the clutch engages, and disengages.

I also hear this hissing noise when the clutch is engaged. Please help.

 

[05YukonDenaliXL]

quite a learning experience for me:
- discharged all the freon
- re-checked the AC lines
- *** i actually forgot to install the washers to seal the lines
- installed the seal washers
- re-tighten the AC lines
- re-charged the AC with freon

now its blowing cool air - ahhhh thank you!

 

[leaf]

Thanks for posting your solution. Did you replace the dryer as well?

 

[05YukonDenaliXL]

Thanks for posting your solution. Did you replace the dryer as well?

No, I did not replace the dryer.

 

[leon72]

Hi guys I know this is an old post. But I need help figuring out why my ac compressor cuts off after a while of driving it. So It works blows cold air then it well suddenly start blowing hot air.. I have not done anything to the as far as maintenance.. I havent noticed any leaks so dont know what the problem could be.. any help can be useful, be the way I have an 04 chevy tahoe...