AC BLOCKAGE

[ELTBIRD]

So I had the Ac system charged with R12 after replacing the dryer but there was still a blockage. My AC man said to check the hoses for blockage and replace the expansion valve which I am aware of. Has anyone had a hose blockage?

[Terry64HT]

I'm suspicious of that explanation. The hoses are a pretty good size to be blocked. Look at points of constriction, like the expansion valve, condenser or evaporator as a start. There are ways to flush the system, but I'm pretty sure you have to have the expansion valve removed or isolated.
I'm going to start to pull mine apart today to try to find a similar problem, but I suspect the condenser.
Terry
64HT

[jtschug]

Ask your AC guy about the position of the rotolocks.

[ELTBIRD]

I beleive the rotolocks are in the stock position. My AC guy specializes in vintage automotive AC system. He has been doing this for many for years. It was determined that there was a blockage when he could not charge the system. Condenser is good and a new drier was installed. There is still a blockage. The expansion valve is the next suspect but according to the tech hoses can deteriorate internally or decicant from the old drier could cause a blockage in a hose. If that were to happen I would suspect the smaller hose coming from the sight glass first. All this being said, the most likely block point is the expansion valve which will be an off season project. I was just asking if anyone had a blockage and it was a hose blockage and nothing else. Seems unlikely to me.

[jtschug]

Has the valve by the sightglass already been removed?

[ELTBIRD]

Yes

[jtschug]

It looks like the suction hose is the old "snake skin" style, probably original to the car, very old hose.

The expansion valve is a likely culprit, but it isn't possible to rule out delamination in a 50-year old hose. If you don't mind the smoother look of more modern refrigerant hose, then I would replace both the suction and liquid lines at the same time as the expansion valve. The hard part is under the dash, but if you going to replace the valve, you are already under there, the suction line just requires one more fitting to be removed.

[ELTBIRD]

Sounds good! I beleive those hose assemblies are available with correct compressor end metal tube attachment fittings. Thanks, Ed

[cacockrum]

Ed,
Another option might be to have Classic Auto Air (calssicautoair.com) restore your original lines. The can refurbish the metal fittings and install new hoses.
Art

[jtschug]

I don't know if they still do it, but big cities used to have Parker or Aeroquip shops that could replicate just about any hose, usually for truckers, but they would do it.

[ELTBIRD]

Hey, thanks for all the caring advise. I will explore all options and go with the one that works for me when I start this project in the off season. Lots of September shows here in NY. I also have a few gigs as I am a drummer in a rock band. They all slow down once the winter sets in.

[sleeper bird]

my bets expansion valve,ask me how i know.

[ELTBIRD]

Hey, thanks for all the caring advise. I will explore all options and go with the one that works for me when I start this project in the off season. Lots of September shows here in NY. I also have a few gigs as I am a drummer in a rock band. They all slow down once the winter sets in.

[ELTBIRD]

I agree sleeper bird....how do you know?

[sleeper bird]

after i changed darn near everything over the years and still had no ac,super high high side pressure and suction side always low.