Reddit reviews Mastercool 85510 R134a Can Tap Valve-Screw-On Model

Yeah, then this is no problems. Just a ton of steps.

Before you go out and do all this, let's make sure your compressor is trying to start. Turn your car off. Plug in your bottle of AC pro. It should be in the red "overcharged" range. Have someone start the car, and then watch the value on the gauge, you should see the value drop into the green when the compressor turns on. That means you just need a proper recharge to fix your AC. Follow the directions below. If it doesn't do that, then you have something else wrong, and we need to fix that first.

Call a bunch of Autozones in your area. A couple of them rent out vacuum pumps + manifold gauges. Call enough of them and you'll find one that will rent you both. Look in the side of the vac pump, it should be full of oil to the fill line. If not, buy a bottle of vac pump oil, and fill it to the "Full" line.

Here's general information:

You need to buy a can tap, even if the gauges come with one. You'll want to save your bottles for later. https://www.amazon.com/Mastercool-85510-R134a-Valve-Screw-Model/dp/B000LQODJC They'll have them at autozone as well. To use a vampire tap, open the silver handle (CCW) all the way. Buy bottles of 134a, screw this onto the top of the bottle, get it handtight. Then close the silver handle all the way. The last few turns it will pierce the top of the top of the can. That'll let you pull the 134 out of the bottle.

Always operate the can with the valve at the top, right way up. Never turn it on it's side, bad things can happen.

When using a vac pump, do not turn the pump on or off while the yellow line is attached. Always turn the pump on, attach the yellow line, let the pump run, then detach the line, turn the pump off.

PPE! Wear leather gloves & safety glasses. Freon burns are not good. Eyes don't grow back.

Find the label on your car that says how much 134a your vehicle takes. It'll be listed by weight. You'll also need a small kitchen scale.

There's 3 different weights of AC oil. Find the correct weight for your car.

Buy a bottle of green or yellow dye, and a blacklight. Hunting for leaks at night/in the evening works much better then during the day. The darker you can get it, the more the dye stands out.

You need a dye/oil injector. https://www.amazon.com/DIY-UV-DYE-INJECTOR-CLAMSHELL/dp/B001DKP0ZG How to use: Unscrew the two parts from each other. Clean out any old oil. Fill up the small part with oil or dye. You must inject a full thing of oil/dye, no half-full, because you'll also be injecting a half-amount of air as well. Hold it level while you screw the other side back on. Tighten it to just past snug. Make sure both both knobs are closed. Take off the lowside (blue) connection. Connect the injector onto your car. Then connect the lineset to the injector. You now need to do something to force dye into the car. Either open the red valve if there's pressure on the red side & nothing is attached to the yellow cable or you can open the valve on can if there's no freon in the system. Then very slowly open the blue valve. You'll see the blue needle spike up, close it down a bit and figure out how to get some small amount of freon going through the lineset. You've now got freon flowing through your injector. Turn it so the black part is straight up and down, you're trying to force all the dye out of the injector and let it flow into your car.

Disconnecting your lineset: If your car is running, you want to try to get as much freon out of the lineset as possible. Make sure your gloves are on. Disconnect the yellow line if connected. Hold down the port on your car and pull up on the red connector's ring. It'll pack a bit of a punch. Put the dust cap back on immediately. Now we'll SLOWLY pull all the freon out of the lineset. Too much at once might damage your compressor. Open the blue knob slowly, watch the blue gauge, open the valve slowly, don't let it go above 60 or so range. Then slowly open the red VERY slowly, same thing, don't let the blue gauge over 60 or so. Once you've got as much freon out of the lineset as possible, disconnect the blue port, and put the dust cap back on. Keep your connectors out of the dust. Dust is your enemy.

Always make sure both knobs are closed before attaching or detaching anything from the lineset.

NEVER EVER EVER EVER open the red valve with anything attached to the yellow line & the car running. This could cause the freon can to explode. You will have a bad day. Check every step you do in here, and make sure you're not breaking this rule.

Steps:

Start by vaccing out the lineset. You need to get any crap out of it that was left by the previous guy. Turn on the pump, attach the lineset. Open both knobs all the way. Let the pump run for ~30 minutes. Disconnect the yellow line, shut off the pump.

Close both knobs. Take off both the dust caps. Pull the collars on the connector back, with your other hand, hold the fitting stable, you don't want to put stress on it. Press the connector in with a smooth motion. It's easier to do with the car off. AC OFF. Start up the car. Watch the values on the two gauges. They have different scales. Both values should be pretty close. Turn on the AC, while watching the gauges. If the needles move, that's the compressor trying to come on. If the pressure gets too high, or too low, the compressor will turn off to protect itself. You may see it cycling on and off as it tries to run. If it's cycling on and off, inject dye into into your system. Follow the directions above for disconnecting your lineset. Find your leak, and fix it.

When you're ready to properly refill your car: CAR OFF! Hook the lineset back up, turn on the vac pump, connect the yellow line to the vac pump. Open both knobs. Listen for the sound of the vac pump as it pulls air out of the system. Listen to the sound, and what the pump is telling you it's doing. At first it's pulling out a lot of air. Then it'll start pulling less and less. Then you'll hear it pulling little bubbles every few seconds, and those seconds will get more and more spread out. Wait for the sound to stabilize, then wait 30 more minutes. This chases all the moisture out of the AC. After 30 minutes, you shouldn't hear any of the sounds of air bubbles. Close both knobs. Wait ~10 minutes. Open the knobs. The sound shouldn't change if you open or close the knobs. If it does, you either didn't vac long enough, or you have a leak. Once you're sure you don't have a leak, disconnect the yellow line from the vac pump. Your system is now at a hard vac! You're in the home stretch.

As you start filling the AC (next paragraph), Inject an injector full of compressor oil. Being at a hard vac tends to boil some of the oil off... the pros have a gauge that measure how much oil that was pulled out, we have to guess. I normally inject 1/4 oz (one injection) or 1/2 (2 injections) of oil. On that large of a car, you might choose 3. Especially if you vacced for a long time. This is more guessing. If your compressor is making a terrible racket, add oil. We unfortunately have to guess on this part. Too little oil, and the compressor won't be lubricated, and will tear itself up. Too much oil, and the compressor will have problems with slugging, and tear itself up.

Connect the injector, and your lineset (Valves closed!), and get out your scale. Car still off. Most ACs will require 2-3 small bottles of freon. Figure out how many full bottles you need to put in, and how much out of the last bottle you'll need. Connect the first bottle. Open the valve on the first bottle. Open the blue knob a little bit for a few seconds to inject the oil into the low side.

This step will injure you if you do not follow directions CAR OFF Really, make sure the car is off, valves closed. Invert the can, valve side down (remember I said not to do this. This one time is an exception. Car off. seriously) Car off. Close the BLUE valve. Open the RED valve. This will dump liquid freon into the high side of the car, which is designed to take high pressure freon, the low side isn't. Let it take as much as quickly as it can. This will quickly dump most of the first can into your AC system, and have it part-way charged. When you stop hearing it flowing around, RED SIDE CLOSED.

yes that works, but I figured free for a tool you'll use once is better than buying it :)

You'll also need to buy one of these to hook up the can of refrigerant to the gauges if you go the buying route https://www.amazon.com/Mastercool-85510-R134a-Valve-Screw-Model/dp/B000LQODJC/ref=pd_bxgy_263_img_3?ie=UTF8&psc=1&refRID=TMMEHPXN9MG3SEA09X5B

Here's some helpful videos on reading the gauges and using them.

https://www.youtube.com/watch?v=UW1GDiOa0kE

https://www.youtube.com/watch?v=lglPJuBXVeE