Initial Charge of A/C

Hi guys, I purchased SPF 2174 and the A/C needs an initial R134 charge. Does anyone know if there is a trick to this for our cars. It looks pretty straight forward based on what I found on the web. I couldn't find any specific threads on the GT40 site.

Any help would be much appreciated.

Thanks
Brad

Hi Brad

No different to any other car.
Just take it to a service centre that specialises in auto aircon and they should be able to sort you out.

Dimi

I normally do this myself, if you have the tools, pull a vacuum on the system and let it sit for 24 hours and see if it leaked down, then if it hasn't add the 134 oil while still under vacuum or use the cans of oil with pre-charge, then add 134 while running at 1500 rpm with AC on. Fill till you see the evaporator temp get between 36-40 degrees F. You may have to check again when summer comes around as the outside temp will affect the evaporator temp on the gauge.

Brad,
Follow Jack's advice. If you have a professional shop do it have them add 3 oz. oil with dye. My SPF had two o ring leaks that I had to replace. Ended up buying the equipment like Jack. Pulling a vacuum for 3 hours instead of 30 minutes finally did the trick. Used 36 oz. r134.

How much vacuum are pulling?

Dean, 28 inches is plenty

Brad:
Definitely make sure that you pull a vacuum on the system, let the pump run for at least an hour, and then check for vacuum leakage. The importance of pulling a vacuum is to boil off any moisture that may be in the system. Also a cheap item to change out is your receiver/drier which contains a dessicant bag and filter to remove moisture and other contaminants that may be in the system. It is a lot cheaper than a compressor. I would also recommend a look at the expansion orifice to see if the screen has any contamination in it.
If the system has been idle for a while or open to atmosphere these are items that should be checked. Make sure you add the correct oil (ESTER) and as was mentioned a leak detector dye...the UV dyes are good when used with the lamp, and can save a lot of headaches when chasing a slow leaker.
Hope some of this helps.
Cheers
Phil

Thanks for all the help guys.
Brad

I have a question about the oil. I bought a can of oil/R134a and it only has 2 oz. of oil in it. Autozone sells a DVD where the guy goes through and replaces the compressor and and bunch of other stuff on a Chevy pickup, that system called for 8oz. of oil and I found 3 different viscosities of PAG oil at NAPA. He put half in the receiver/dryer and the other half into the suction side of the compressor. So bottom line, how much of what, and where? Thanks.

Richard,
The Sanden compressor already has oil. I added 3 oz. when I charged the system (fitting after evaporator). If you have the system apart I suppose you could add it at the drier. I used the medium viscosity PAG oil as recommended by Sanden. Looking forward to your first drive. You've been a long time with your build.

Thanks, that's a great help. I have a bottle of PAG46 will that work? Can't wait to drive it, yes it's been long, long build. Pictures just because. The slave bracket is my tribute to 60's technology before Solid Works and CNC. Body parts have been in the living room for a long time.

Rich,

Good luck with your first drive.

P.S. I really like the swiss cheesed bracketry. Shows alot of attention to detail.

The other Rich.