How much refrigerant do these things hold?

[davepl]

I ordered this manifold set to vacuum down my AC system, and because I've never had an AC manifold hose set:

Amazon.com: Mastercool (89660-PRO5) R134a...
Anyway, in the event I discover that all my parts and o-ring replacement worked (ie: it holds good vacuum perfectly) should I at that point go ahead and add coolant, or if I've got that far should I just do it myself?

If that's the case, do I need the big propane BBQ tank size or is it practical and cost-effective to use the R-134 cans from the local auto parts store? I don't know how many spray-can size cans these would take, so maybe it's a silly question.

[Wrenchbender Ret]

If you have gone this far you can fill it yourself. It would be hard for me to explane it all in a post here. You might be able to study up on the procedure using the internet or maybe a book. The factory system uses 4 cans if you are still using the POA system. Most after market systems use 2 cans.

[FirstOwner69]

Below is a picture from my 69 that says 3.25 # of R-12 on a sticker placed over 3.75# printed on the label itself. I think the later years didn't have the sticker and had the 3.75# exposed. The difference may be due to the fact that one of the hoses was longer than in 69 (69 and earlier hoses also used gear clamps rather than being crimped). I'm not sure how 134a weight compares to R-12 weight per unit volume.

[Bad Jackson]

A 30 lb bottle of 134a will run you about $100. The cans are way cheaper. (Cuz you only need 3-4 lbs. Usually 12 or 16 oz per can. Also, I think some places will you to have your EPA Certification to buy that much (30 lb bottle)

[davepl]

Thanks! I'm vacuuming it down now. My sticker is a reproduction sticker and says 4lbs (I didn't know it said that until someone else mentioned their own sticker).

I think that works out to about 60 oz, or 5 cans, or about $150. They also sell a "first charge" that includes the oil.

I installed a new compressor, condenser, and dryer. The compressor had oil in it (from LMC). How do I know if that oil is compatible with R-134a? All I know is it was beige!

Similarly, will residue of old R-12 oil in my lines cause a nuclear explosion?

Sucks doing this stuff the first time, but everything I do was once a first time...

[motorcritter]

Vacuum it down and flush it to remove any nastiness. R134a volume is usually about 20% less than R12 volume. Watch your pressures, and check for leaks- install UV dye when you fill it.

[davepl]

Sadly it lost about an inch of mercury an hour after pulling it down to 29". Too small of a leak for me to chase down and too big to ignore, so I'm going to have to take it somewhere.

Probably for the best, but I had fun playing with the tools and learning how to use them if nothing else.

[68shortwide]

Never seen a pic of the truck, front looks great