A/c in 72 burb finally working

[4shongo]

Well after lots of time and money, it is finally alive. Replaced: R4 compressor (I have a late model crate motor), dryer, expansion valve, and the POA valve delete upgrade from Classic Air. Result....44 degree vent air....nice and cool now both front and back units!!!! I weighed in the charge of 3lb 3oz of 134A.

Best advise I can give, if you are having issues is to flush your condenser and evaporator coils. I couldn't believe the amount of nasty oil came out of those things (especially the evaporator). Basically the system was oil logged and couldn't move any refrigerant. Plus I will assume that the nasty oil caused the factory POA valve and expansion valve to be clogged. After 40 years, you never know how much oil has been added or what has been truly done to your system.

All is well now and the wife is happy....now we can take the Burb to the Street Nationals next month!!!!

[Advanced Design]

Congratulations on getting the AC going. Good advice on the flushing. Did you flush with refrigerant?

[4shongo]

Originally Posted by Advanced Design

Congratulations on getting the AC going. Good advice on the flushing. Did you flush with refrigerant?

No I actually purchased a flushing agent spray (20 oz aerosol can) from the local ac supply house. Directions said to first flush lines with air and then spray flush agent, let stand for 10 minutes then flush out with air again. Unbelievable the amount that came out. I saturated a full size towel trying to catch the crap that came out if that gives you an idea. It was really messy!!!!!

I vacuumed the system for 8 hours and held the vacuum overnight to be sure it was good.

[jjzepplin]

This is great advice! How much was the flushing agent?

[Bigdav160]

Good news. Any pics of the engine compartment connections?

Using a R4 moves the lines closer to the core support making the use of an "off the shelf" OE line more difficult. Did you change the condenser?

I thought my mastercool set would make new ends for the hard line but it doesn't do 1/2" line. My plan is to cut, swage and weld to make some new ones.

[4shongo]

Originally Posted by Bigdav160

Good news. Any pics of the engine compartment connections?

Using a R4 moves the lines closer to the core support making the use of an "off the shelf" OE line more difficult. Did you change the condenser?

I thought my mastercool set would make new ends for the hard line but it doesn't do 1/2" line. My plan is to cut, swage and weld to make some new ones.

Sorry no pics. It was changed over to an R4 compressor (134A) around 2000 when the restoration was completed by the previous owner and the late model motor was installed from my understanding. I had to change the compressor because the front seals were leaking. Lines look factory to me except for the actual compressor fittings. Hard to tell what truly has been done over the life of these trucks. I did not replace the condenser.