Air conditioning overhaul

[cory58]

+1 L.C. Wylie kit. He is very helpful and answered all of my questions. Yes, you can save money piecing the kit together yourself, but it's the custom made lines that will be an issue tracking down. The kit is worth the price and saves a lot of headache.

My only recommendation would be to also replace the evaporator. I was able to re-use my existing dual pressure sensor setup (early model), but I do have a new plug for converting if I need to. Make sure you do the R12 to R134a capacity conversion as well. I originally overfilled to ~ 1.89lbs, which was too high and caused the system to not work correctly. I had a shop do a proper evac and fill and I think I recall them telling me it was about 1.55lbs of R134a to fill the system. It works fantastic now and definitely worth it.

Happy to answer any questions you have about an R134a conversion on a convertible.

Good luck!

What were the symptoms when the system was overcharged?

Thanks, Cory

[m2d2]

It was blowing cold air for a few minutes and pretty much stopped blowing entirely. I believe the overcharging tripped the high pressure sensor and caused the compressor to shut off, but can't verify that. With less charge I haven't had any issues.

[notporgu]

Sorry for reviving an old thread, but just wanted to update and ask another question.

I ended up going with Layne, and he was very helpful with the whole process and even gave me an option on the store to buy only the parts from the kit that I needed. Very satisfied, can't wait for his stuff to arrive in a little while.

Now for my question. When I was tearing down my ac parts to get everything out for replacement, the insulation putty that was on the expansion valve sort of... disintegrated. I know this is a pretty important pile of putty, if I don't want my car to have condensation leak all over the floor, but there's no way I'll be able to reuse it in it's current state. Is there another option that I could use instead? I'm sure something generic would work I just don't even know what to look for.

[Tzantushka]

You can buy the insulation tape from most HVAC suppliers - it’s called prestite tape. Have a look at post 57 of my build thread - I used self adhesive insulation tape and it works brilliantly.

[notporgu]

You can buy the insulation tape from most HVAC suppliers - it’s called prestite tape. Have a look at post 57 of my build thread - I used self adhesive insulation tape and it works brilliantly.

Ok awesome, thanks!

[notporgu]

Again hate to revive old thread, but I got all my parts in and installed the other day, and had an evac and recharge done to it yesterday.

When we finished the recharge, I started it up and engaged the compressor to... sub par results. The air was definitely cold, it wasn't blowing hot for sure, but if I had to guess it wasn't even close to sub 60s. I didn't think much of it, but by the time I got home, the compressor was no longer engaging and it was blowing hot.

I did some probing and found that one of the pressure sensors was cutting power to the compressor. I've tried doing lots of research, but there's little to no info on what pressures these sensors are rated for, so I have no concrete info on what's wrong.

What I do know:
Research tells me that the original R12 system took somewhere between 2 and 2.2 lbs, so following the 80% conversion rule, we put in 1.8 lbs of 134a.
In my attempt to find the right replacement sensor to get pressure values, I found in the second post of this thread that the sensor I'm looking for is the low pressure sensor (pn 64531370463, can be found here).

Now I'm not sure if I have a bad sensor, or if I have low pressure. Following what M2D2 said, I would have over charged my system, leading to the cutting out of the compressor, as I charged it to 1.8 like he did. However, that doesn't account for the other post saying that it's the low pressure switch that's going out, and that my system never really got cold.

My intuition says to recharge it to something like 2lbs, but I'm not sure if it could also be the sensor or not.

Any advice is appreciated! Thanks