Automotive Air Conditioning Information Forum

Which manifold gauges would be best for automotive use?

Hopefully I'll be using them rather frequently.

I don't want the digital ones, but I also want to cheap out on a set even though I'd prefer inexpensive.

If you are going to work on mostly R134A but may do some R12 work get a R134A manifold with 1/4" fittings and a hose set with 1/4" fittings as well. Get a set of the R134A quick disconnect adapters along with 1/4" to 1/2" Acme M/F adapters in both directions.

Pressure is pressure so you can use the R134A gauges on R12 but the P/T scale can't be used for R12.

I don't ever purge a line if I can avoid it, I pull a vacuum on lines, gauge set, etc. Add a "T" fitting like this: http://www.centurytool.net/3_Pack_T_Con ... savt45.htm and a ball valve like this: http://www.centurytool.net/Hose_End_Bal ... cpsbv3.htm to the center of your manifold to connect a vacuum pump.

Source for 1/2" Acme to 1/4" flare adapters as well: http://www.centurytool.net/AD48_CPS_1_4 ... psad48.htm

Thanks wptski. What do you use for gauges?

Most forums say Yellow Jacket is best. With that T fitting, I won't necessarily need a 4 port. Maybe something like this with the ball end valves and connector you recommended:

https://www.amazon.com/Yellow-Jacket-42 ... +gauge+set

Another question that I had is, how do you account for the refrigerant that stays in the hoses. What I mean is, when weighing, you're supposed to add a certain amount, but some stays in gauge and hoses. Is it a small enough amount to not make a difference?

72gmc4x4 wrote:Thanks wptski. What do you use for gauges?

Most forums say Yellow Jacket is best. With that T fitting, I won't necessarily need a 4 port. Maybe something like this with the ball end valves and connector you recommended:

https://www.amazon.com/Yellow-Jacket-42 ... +gauge+set

Another question that I had is, how do you account for the refrigerant that stays in the hoses. What I mean is, when weighing, you're supposed to add a certain amount, but some stays in gauge and hoses. Is it a small enough amount to not make a difference?

That's the YJ manifold that I have but unsure if I got the hoses with it as they are all 1/4" swivels. Ball valves come in handy.

I fill the lines first, zero or tare(correct word) the scale and then add the correct weight for the system. Seems like most times that around 3oz. System under a vacuum, I charge using liquid(inverted jug) on the high side.

Santech.

http://www.ackits.com/mt1416-santech-r1 ... oses-24615