Mastercool or Yellow jacket ac gauges

[SC Maintenance]

Where do I find one of these valves with the Schrader valve - to purge the charging hose?

 

[wtd]

I read elsewhere that I should use it on all the hose connections on the manifold set?

Where else should I use it. Any o-ring I replace presumably. Anywhere else?

I use it on O-rings and screwed connections on any lines I take apart.

 

[CarbonToast]

Where do I find one of these valves with the Schrader valve - to purge the charging hose?

View attachment 280341

I just poke the Schrader with a small screw driver till a puff comes out. I guess if you had a empty can you could rig a hose with a can tap on each side.

Just realized it. You could use that port as the connection for the vacuum pump. This way you can vac the systems, gauges, and hoses.

 

[GON]

This is what I did back in 2006 when I had a car that my fiancé wanted the air to work in but to have someone else to repair it was almost as much as the car was worth.
She told me she would buy me the tools if I learned how to do the work. I bought a couple of books and found an automotive AC forum with a lot of knowledgeable guys on it and some of them were actual AC techs.

I bought Robinair gauges. One set was for r134a and one for R12 since I still had a car that took it. I bought a Robinair 6cfm two stage vacuum pump which is overkill for automotive AC work, but it works great. I change the oil with Robinar vacuum pump oil after every use per the owner's manual and the pump still works like new after all of these years. I did have to replace the fittings for ones for automotive use which I bought from Robinair.
I initially used the small cans to charge with, but they were a pain to use to get the exact refrigerant amounts, so I bought a Mastercool refrigerant scale for the 30 lb tanks and bought a 30 lb tanks of r134. That was a game changer since it made recharging so much easier without having to disconnect the lines to switch cans and purge the lines of air. Someone later sold me an almost full 50 lb tank of R12 which I still have today with most of it still left. During that time, I also got my 609 certificate so that I could buy R12 from those who required it. This was when I was buying the cans and before I bought the 50 lb tank. I bought several 30 lb tanks of r134 some years back when they were still reasonably priced, so I have enough to last me quite some time.

The only thing that I don't have is a machine to reclaim refrigerant. For friends and family who want me to work on their AC systems and it needs to be empty, they have to go somewhere to have that part done. I also take my own vehicles somewhere to have it done if needed.

To date, I have successfully fixed around 25 vehicles with only one failure to fix.

Here is the AC forum that I learned a ton from.
https://www.autoacforum.com/

@wtd , very helpful and beneficial write up. Thank you.

 

[Nukeman7]

Where do I find one of these valves with the Schrader valve - to purge the charging hose?

I think any of these tees will work with the Mastercool manifold if you remove the Schrader valve from the bottom threaded end where you would connect the yellow hose.

Manifold Purge Tee

 

[D60]

Apparently ammo guys sometimes use refrigerant scales for reloading, or at least that's how I stumbled onto mine. So, if you're shopping used and you have contacts in those circles, keep your ear to the ground.

You don't really need a scale for occasional use, and they're arguably impractical for the small cans unless you can ensure you don't disturb the hoses. Very difficult to measure a tiny can down to an ounce when it's being manipulated and flopped about by hoses that lay across the grille or rub or hang up on things

 

[wtd]

Apparently ammo guys sometimes use refrigerant scales for reloading, or at least that's how I stumbled onto mine. So, if you're shopping used and you have contacts in those circles, keep your ear to the ground.

You don't really need a scale for occasional use, and they're arguably impractical for the small cans unless you can ensure you don't disturb the hoses. Very difficult to measure a tiny can down to an ounce when it's being manipulated and flopped about by hoses that lay across the grille or rub or hang up on things

This plus I've had the can taps malfunction, and I would lose all of my refrigerant that was in the can.

 

[D60]

This plus I've had the can taps malfunction, and I would lose all of my refrigerant that was in the can.

I've been considering the side-puncture taps for the small cans. Seems a good way to bypass all the nanny state self-sealing nonsense but I don't know how well the puncture style really works? I imagine eventually they'll prohibit their production or inclusion in kits.

 

[SC Maintenance]

I just poke the Schrader with a small screw driver till a puff comes out. I guess if you had a empty can you could rig a hose with a can tap on each side.

Just realized it. You could use that port as the connection for the vacuum pump. This way you can vac the systems, gauges, and hoses.

The one I ordered does not appear to have that Schrader valve. I think I found a fitting on Amazon that does so I guess I will add it.

 

[Nukeman7]

I've been considering the side-puncture taps for the small cans. Seems a good way to bypass all the nanny state self-sealing nonsense but I don't know how well the puncture style really works? I imagine eventually they'll prohibit their production or inclusion in kits.

The side puncture clamp-on taps work as advertised. Since it has to stay attached on the can until depleted, the thick rubber sealing grommet surrounding the needle will eventually become compressed and not seal 100%, allowing the refrigerant to slowly leak out. I only use my side piercing tap when I'm certain that I will expend all of the refrigerant during a charge or if the self-sealing top valve malfunctions.

 

[wtd]

I've been considering the side-puncture taps for the small cans. Seems a good way to bypass all the nanny state self-sealing nonsense but I don't know how well the puncture style really works? I imagine eventually they'll prohibit their production or inclusion in kits.

That is the kind I had malfunction. It was a Robinair one and the Shrader valve was bad. I had another one just like it that has always worked fine. I think they work better than the ones that attach to the top.

I don't like using cans for the reasons I stated above but I get that for most DIY people buying a tank of r134 and a refrigerant scale is overkill. I was willing to spend the roughly $450 at the time for the convenience of that setup and it has come in very handy over the years and I don't regret the purchase at all.

We do have one vehicle that uses the yf1234 but I have not bought the gauges or refrigerant for that which is very expensive. At some point I probably will.

 

[Chevyc10]

I own several HVAC supply houses. Sold several brands of manifold gauges. Yellow Jacket is best in my opinion. Master cool 2nd. The Fieldpiece electronic 3rd.
Yellow Jacket hoses are best and last longest.
Just used some with 1992 date code and they were still flexible and sealed.
Vacuum pump brand doesn’t matter, buy 2 stage only. Old days you could buy kit and rebuild them yourself. Now disposable so buy cheap. I like small cfm because they are lightweight. Too big a pump can cause issues. Your hoses are just so big inside. Customer works on grocery store refrigeration racks. Uses a tiny vacuum pump.

 

[demarpaint]

Yellow Jacket.

 

[SC Maintenance]

I am going to revive this thread because I am lost again, even though I seem to be making some progress on my actual repair thread. I bought this mastercool set on the suggestion of @Nukeman7 Mastercool set , and it seems to be very high quality, but I am having issues with it.

Best I can tell the yellow hose has 1/2" ACME on both ends, one end has a bit of an angle and has a one way valve. It looks like a Schrader, but its a large brass tab and doesn't come out - so I assume its integral to the hose.

I connected the angle end to my vacuum pump, but it would not open the valve - ie no vacuum. I swapped ends and again, it won't pull vacuum past the valve. I disconnected the far end from the manifold and pushed manually on the valve and I got vacuum, although it seemed like it would not push very far- seemed very restrictive.

I swapped the yellow hose with one of the other hoses - which both have a 1/4 flare on one end and a 1/2 ACME (I think?) on the other with a valve - the valve end on the manifold. The pump has both connections. I could then pull a vacuum no problem - other than I was short a hose so only could pull from one side.

So my questions:

1) Does it sound like the yello hose is broken? Or do I need some sort of adapter to depress the valve.

2) Are these hoses standard - 1/2 ACME x 1/4 flare on red/blue and 1/2 ACME on both ends of the yellow, and all hoses with the valve? I have researched around and it seems like everyone is different.

I am at a loss on what to do next - try another one of these sets, buy something else, buy new hoses? I can still return this one?

 

[Nukeman7]

I am going to revive this thread because I am lost again, even though I seem to be making some progress on my actual repair thread. I bought this mastercool set on the suggestion of @Nukeman7 Mastercool set , and it seems to be very high quality, but I am having issues with it.

Best I can tell the yellow hose has 1/2" ACME on both ends, one end has a bit of an angle and has a one way valve. It looks like a Schrader, but its a large brass tab and doesn't come out - so I assume its integral to the hose.

I appear to have the exact same yellow hose based upon your description.

I connected the angle end to my vacuum pump, but it would not open the valve - ie no vacuum. I swapped ends and again, it won't pull vacuum past the valve. I disconnected the far end from the manifold and pushed manually on the valve and I got vacuum, although it seemed like it would not push very far- seemed very restrictive.

My yellow hose has the same appearance and behavior, except it will allow vacuum to pass when the angled end is connected to the Robinair vacuum pump.

I swapped the yellow hose with one of the other hoses - which both have a 1/4 flare on one end and a 1/2 ACME (I think?) on the other with a valve - the valve end on the manifold. The pump has both connections. I could then pull a vacuum no problem - other than I was short a hose so only could pull from one side.

So my questions:

1) Does it sound like the yello hose is broken? Or do I need some sort of adapter to depress the valve.

Yes, the rubber valve might be stuck/defective. Try this: take the disconnected yellow hose and see if you can get R-134a to pass through it (assuming you have the proper dispensing valve). That might get the rubber valve to reseat itself. FYI, my yellow hose does not pass 15 psi compressed air from my blowgun in either direction.

2) Are these hoses standard - 1/2 ACME x 1/4 flare on red/blue and 1/2 ACME on both ends of the yellow, and all hoses with the valve? I have researched around and it seems like everyone is different.

I am at a loss on what to do next - try another one of these sets, buy something else, buy new hoses? I can still return this one?

The hoses for R-134a are standardized. I have a different set of hoses for charging R-12 & R-22 refrigerant. If it doesn't work correctly with a different vacuum pump, you should return it within the allowable window.

Here is a photo of my Mastercool gauge/hose setup with LiChamp QD connectors attached. The angled brass connector on the yellow hose is shown parked on the vent Tee coupling on the manifold, but is connected to the vacuum pump or R-134a canister during use.

 

[SC Maintenance]

I appear to have the exact same yellow hose based upon your description.

My yellow hose has the same appearance and behavior, except it will allow vacuum to pass when the angled end is connected to the Robinair vacuum pump.

Yes, the rubber valve might be stuck/defective. Try this: take the disconnected yellow hose and see if you can get R-134a to pass through it (assuming you have the proper dispensing valve). That might get the rubber valve to reseat itself. FYI, my yellow hose does not pass 15 psi compressed air from my blowgun in either direction.

The hoses for R-134a are standardized. I have a different set of hoses for charging R-12 & R-22 refrigerant. If it doesn't work correctly with a different vacuum pump, you should return it within the allowable window.

Here is a photo of my Mastercool gauge/hose setup with LiChamp QD connectors attached. The angled brass connector on the yellow hose is shown parked on the vent Tee coupling on the manifold, but is connected to the vacuum pump or R-134a canister during use.

View attachment 284398

Good idea with the can tap. So with a can that has maybe a little less than half, it would literally squeel like a clown horn while opening the tap, and at fully open very little came out. There was lots more pressure on that can with just the tap. With a full can, it was much better. Still seems very restrictive to me. The valve does seem to move a little more than it did. Is this by design? Are they all like this? Seems like an impediment to get everything out of the can.

Also, if I were going to use it with a vacuum pump I would need some sort of fitting to depress the valve. Hard to see here, but the valve seems very low in the coupling - the top pin is below the bottom of the rubber taper seal. Maybe a fitting with some sort of long nipple?

 

[Nukeman7]

Good idea with the can tap. So with a can that has maybe a little less than half, it would literally squeel like a clown horn while opening the tap, and at fully open very little came out. There was lots more pressure on that can with just the tap. With a full can, it was much better. Still seems very restrictive to me. The valve does seem to move a little more than it did. Is this by design? Are they all like this? Seems like an impediment to get everything out of the can.

Based on your observations, I suspect your yellow hose is defective. The R-134a flows freely through my yellow hose at a rate comparable to the can tap alone.

Also, if I were going to use it with a vacuum pump I would need some sort of fitting to depress the valve. Hard to see here, but the valve seems very low in the coupling - the top pin is below the bottom of the rubber taper seal. Maybe a fitting with some sort of long nipple?

No, if the yellow hose is not defective, vacuum will flow through the valve without depressing anything. The male threaded port on the vacuum pump is completely open and I just screw the angled coupling onto it and activate the pump to get suction. Your coupling looks just like my coupling with the valve depressor tang deeply recessed.

 

[GON]

A little update.

Four Seasons also sells a gauge set. Sets for sale on RockAuto.

I spent some time to see if the Four Seasons might be the same as Mastercool, RobinAir, or Yellow Jacket. Four Seasons gauges do not seem like relabeled of those other brands.

Now have to learn the difference between brass or aluminum gauges.

 

[Nukeman7]

I spent some time to see if the Four Seasons might be the same as Mastercool, RobinAir, or Yellow Jacket. Four Seasons gauges do not seem like relabeled of those other brands.

Now have to learn the difference between brass or aluminum gauges.

Here is my take on the differences between the brass and aluminum gauge sets:

Brass: Favored by residential/business HVAC professionals because it is more durable and serviceable (e.g., multiple replaceable o-ring seals in valves, no fragile plastic sight glass window, brass is harder and more corrosion resistant when exposed to the elements in the field).

Billet aluminum manifold: Has additional convenience benefits, especially for automotive and amateur mechanics (e.g., sight glass, parking storage ports for QD Couplers, Tee connector with Schrader valve port for purging air and parking the yellow hose, the Tee also allows connecting refrigerant canister to manifold without disconnecting the vacuum pump if you own 2 yellow hoses). Many of the aluminum manifolds have isolation valves with plastic knobs instead of the metal handles found on the brass manifolds.

Funny thing is that Mastercool calls the brass manifold gauge set "Heavy Duty" and the aluminum manifold set (which I own) as a "Pro" gauge set.

 

[SC Maintenance]

I have the brass Mastercool 66661 I think. Unfortunately I could not use it because it has a defective yellow hose. I have a return already set up with Amazon, but I still wonder if I would be better to get them to send me another one instead, its seems otherwise very good quality for the price.

It does have an attachment to park the blue and red hoses. A sight glass would be nice I think though?

I spent a lot of time reading through both Reddit/r/HVAC and also autoacforum - where the owner of that site also sells tools. more confused now than when I started