Need to charge the A/C, don't know how to connect the gauge to the R134A can

[dcdyd]

I need to recharge the A/C because the compressor is on and off in about 4 seconds and the low end reading is cycling between 20-45 and the high end is about 140-120. So I sent to to the local store and brought two cans of R134A. By the way the truck is 98 5.0L.

Thought that jusy connect the yellow cable of the gauge to the can at one end and the other end to the gauge. HOwever it doesn't seem to me that the can was not opened.

Disconnect the yellow cable and found that the cap of the can wasn't open. See below picture of the can and the end of the yellow charge hose.

R134A can

Yellow (charge hose) of the gauge

First time I connected the yellow hose with the can, I use hand to tighten the hose with the can but it doesn't seem to me that the hose can break the cap of the can. Did I do something wrone or should I use some tool to open the can?

Looking inside the hose, I don;t know how it can open the can without using anything else. I need A/C because it is above 90F everyday. THank you in advance.

 

[71cutty455]

You need a can tap that pierces the can and has a port to hook up the hose, search ebay for "r134 can tap".

 

[my98nnj]

Go back to the local store and by the recharge kit.
You'll get a hose with it.

 

[dcdyd]

Thank you all for the suggestion. I will go to Walmart today.

 

[RomeovilleIL]

This is what the charging hose with can tap looks like

http://www.amazon.com/R134a-U-Charge-Hose-Refrigerant-FJC/dp/B003T0TN6A

You screw the hose onto the can with the tap up (do not pierce the can yet), then hook up the fitting to the low pressure port. Once everything is connected then you turn the tap in to puncture the can, back the tap back up to let the refrigerant flow out. Once the can is empty or the system is full, screw the tap back down to seal the can and then disconnect the fitting from the port.

 

[dcdyd]

Local Walmart didn't have the can tap. Went to O'reilly and got one at $6.99 plus tax. Put 2 can's of 134A and the a/c starts working again. THank you all for the help! Really appreciated.