I'm trying to recharge my A/C system with a hose/gauge manifold (the red, yellow, blue hoses) after pumping out all the pressure in the system. The problem I have is when I attach a can of freon on to the 134a can-tap and turn the handle that will screw the needle down to push down the piston that will let out the contents, nothing comes out. I don't hear gas escaping the can, nothing comes out when I try to release pressure from the yellow hose, nor was there any gain in pressure on the blue gauge when I tried releasing it into the system.

Later I got a can of freon that I haven't tried yet, attached them to a single gauge and hose, saw that the can worked; and then when trying the can-tap from the hose/gauge manifold (and having it fail again), it would not work with the single gauge/hose afterwards.

Another thing I should mention is that the hoses, gauges, can-tap, cans of freon, and vehicle's A/C system are all 134a.

So what's going on? It looks like I'm breaking the can's piston every time yet I'm taking it slow and being very careful. Do I have a bad can tap? Or am I doing this wrong?

  • " Do I have a bad can tap?" Sounds like it
    – Moab
    Commented Sep 4, 2020 at 1:37
  • Welcome to Motor Vehicle Maintenance & Repair! It's either as Moab states, or quite possibly you aren't using the components correctly ... namely the can tap. Just a thought, though. Commented Sep 4, 2020 at 12:40
  • Recently the can designs have changed. The newer cans have a valve instead of a surface to be punctured. They each use a different type of tap. Are you using the correct tap for your can.
    – Jupiter
    Commented Sep 4, 2020 at 15:41

1 Answer 1


Check the can of air you have. If it's a resealable can, you will need a self-sealing tap. If it's a puncture-type can, you need a puncture tap.

If you have a resealable can, puncture taps will not work; they'll pierce the membrane, and when withdrawn, the membrane will reseal itself. So no 134A will be transferred to the Yellow hose.

Look at your can tap. The tap for a self-sealing tap generally (I haven't looked at at them all) has a flat pin. The tap for a standard puncture-type can has a point on it, so it can pierce the metal top of the can.

Self-sealing tap

Self-sealing tap

Puncture tap

enter image description here

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