AC leak on firewall

[tobaccogrower]

I noticed my AC was not as cold as in the past. looking around I noticed some oil on the aluminum block on the firewall the lines go into. there is a single bolt that looks like it holds the two halves together.

So, whats behind that block? o rings? Is it something I can repair myself or better left to a professional? I have access to R12 so that's not a problem recharging it after the repair. If I pull that plate I imagine I'll get a face full of oil and R12 correct? should I have the R12 captured before I attempt any repairs?

 

[Bob4x4]

the block is the expansion valve,you will have to reclaim the system before opening any plumbing to make repairs

 

[RSchwarzli]

The aluminum block is the expansion valve, also known as H valve. This regulates the liquid freon heading into the cab evaporator in the heater box.

Either side of the expansion valve is a seal/gasket. Never just crack the system open if you suspect it to still have some pressure in it. Have it reclaimed.

Now, if the system is empty, it is easy. Remove that one bolt, you will need two gaskets, and if memory serves, there is also two O rings for the cab side of the H valve although I am not 100% sure on that. Simple to do. Remove bolt, the front line will come off. Remove gasket. You will find two bolts in H valve holding it to the evaporator hose, remove those, second gasket is there. While having the H valve out, clean it out to ensure the metering device is not plugged. Once clean make sure hose surfaces and H valve surfaces are clean. Install new gaskets and reassemble. Then, before charging the system, install a new filter/drier. That is to be changed ANYTIME the system is exposed to atmosphere.

Thats it!

 

[DVolk]

Need to add one thing . Always install he " O" rings wet with some refrigerant oil they have spray cans avalible if you dont they will leak .
I learned that one from my dad whom had 40 years in automotive ac and radaitors .