tjordan

The low pressure A/C fitting on my 05 A4 1.8T has a very slow leak and the valve core(schrader valve)needs to be replaced. There are tools made by Mastercool and Interdynamics that can be used to replace the valves while the system is still under pressure. Unfortunately not all makes of cars have the same size fitting. Has anyone ever used one of these tools to replace the valve and if so which tool, manufacturer and part number? Thanks.

Tom Settle

I bought the Mastercool valve tool 81490 for 134A but it doesn't work. There are JRA valve cores, which I believe is a M6(metric), there are also M8, M10. I called Mastercool and they have no idea what car uses what. I'm still trying to find the size in '14 Q5. I read that the JRA is now the most common , would be nice to know the exact size.

W261w261

This reminds of the car guy trivia question: what is the part, common to all cars since around the late 20's and still in use today?

Tom Settle

Obviously you don't have a clue which size valve is used in Audi's Lo and High A/C ports. Pneumatic tires

turbo510

Alright, Tom Settle. There's not a whole lot of action on this forum anymore, but W261W261 livens it up now and then with an interesting story. No need to go nasty right out of the gate.

W261w261

I am definitely guilty of the periodic thread drift.

W261w261

I guess the question is more properly asked: what part is essentially unchanged since the 20's, and has been in constant use? It's the Schrader valve.

Tom Settle

I tried Mastercool's tools on my Q5 21014 I had to purchase the Master Set in order to get the right tool, problem was I couldn't get the old valve to pass through the ball valve. The charge finally got so low I could replace the valve. The valve is a M6 with the purple seal around it. Recharged it and seems to be holding up. EBay has the valves(purple) for $5. hope this helps.

Tom Settle

The schrader valve has changed. Not only the small valve in stems and tubes, JAC valves, M6 valves, M8 and M10, refering to there size in mm.

Tom Settle

Was just hoping for an answer to a technical question. Nasty wasn't my intent.