What is the normal operation of the shrader valve on the high pressure side? I have a major leak identified when trying to charge the system. The post below references replacement of the shrader valve but alludes to it leaking after replacement. Is there any condition where it would leak and not be bad?

https://www.fiero.nl/forum/Forum2/HTML/085658.html

It should not leak. If it is, then it is failed. The cap will help as a secondary seal too.

It can't be allowed to leak. You can see up to 400 PSI at that valve. Unfortunately there isn't a way to replace it without discharging the system.

quote Originally posted by TK: Unfortunately there isn't a way to replace it without discharging the system.

not true, but the cost of the tool is more than the freon.

quote Originally posted by buddycraigg: not true, but the cost of the tool is more than the freon.

Th tool can only tighten the valve on the seat. If the valve is leaking no tool will help.

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87GT - 3800SC Series III engine, 3.4" Pulley Flotech Exhaust Autolite 104's 4T65eHD
87GT - 3.4L Turbocharged engine, modified TH125H
" I'M ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by buddycraigg: not true, but the cost of the tool is more than the freon.

I was thinking about that when I was typing. I guess you could put the car in a chamber pressurized to the static pressure of the system (like around 75psi) and swap the valve.

Or maybe there is a tool that you put the new valve in, screw it on, remove the old valve and insert the new one.

I'd just evac and get a couple more cans of freon myself!

http://www.sjdiscounttools.com/mas58490.html

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Dave

www.ltlfrari.com

thanks dave.
at least someone believed me.

Here's another (cheaper) one:

Went to Napa. Their ac valve tool was too big. Turns out the R134a conversion adapter has some type of extention built in it. I'm going to have to get the R134a conversion adapter off before I can get the valve stem out. Only problem is that the adapter has thread sealer. Anyone know a way to get it off without destroying the ac tube?

[This message has been edited by flimbob (edited 06-03-2008).]

Charging? With R134 I'm guessing?

Don't replace the high side valve. That GM high side valve was a POS for R12. Replacing it often does not fix a leak there regardless of refrigerant used. The high side seals against the neck of the fitting. IE the valve neck is part of the actual valve, unlike a schrader that seals against itself after pressing the stem. The smallest defect in the valve neck will keep the high side from ever sealing properly even with R12.

Unless you've got a metal cap for R134, it is Not going to provide any significant seal beyond keeping dirt out. High side even more so.

You need a high side R134 fitting that has it's own valve in it. They do make them and you'll likely have to find someone other than a chain parts store to get it. This is the only reliable high side valve fix. If you have the simple pass thru type adapter that comes with most conversion kits you'll have to be extremely careful removing it. Twist too hard and you'll snap off the whole thing or break the line.

If you are running R12... try an angled valve extender that has it's own valve. That or use a METAL cap and AC rated thread sealer as soon as you are done charging.

There's more about this in my cave. (interior dept.)

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top of every forum page...)

quote Originally posted by buddycraigg: thanks dave. at least someone believed me.

I believe you now! I've never seen one but then I don't do AC for a living. Cool device.

Edit: I keep staring at that tool. That is an amazing piece of work.

[This message has been edited by TK (edited 06-03-2008).]

quote Originally posted by TK: Edit: I keep staring at that tool. That is an amazing piece of work.

aint it cool (AC pun intended)...

quote Originally posted by flimbob: What is the normal operation of the shrader valve on the high pressure side? I have a major leak identified when trying to charge the system. The post below references replacement of the shrader valve but alludes to it leaking after replacement. Is there any condition where it would leak and not be bad? https://www.fiero.nl/forum/Forum2/HTML/085658.html

I've had one leak vacuum but sealed fine under pressure. But any leak is still a leak if it still continues. If you are converting it to R134, make sure the adaptors are self sealed and not just ententions to push on the existing shrader valves. Some adaptors R-12 to R-134, have simple screw on collars that still utilize the original valves. Some adaptors are stand alone valves. If they are the latter ones, you have to remove the original shrader valves before you install the adaptors. If you have a question about a valve leaking, just take some dish washing liquid and mix a little water (thick on the soap) and smear across the valve opening. If the valve blows a bubble you have a leak. Or you can go to a propane supply company and get some leak spray solution to spray everyware and see if you have bubbles too.

Good Luck..

See you this weekend.

Bob

Bob,

Sent you a PM.

quote Originally posted by theogre: Charging? With R134 I'm guessing? Don't replace the high side valve. That GM high side valve was a POS for R12. Replacing it often does not fix a leak there regardless of refrigerant used. The high side seals against the neck of the fitting. IE the valve neck is part of the actual valve, unlike a schrader that seals against itself after pressing the stem. The smallest defect in the valve neck will keep the high side from ever sealing properly even with R12. Unless you've got a metal cap for R134, it is Not going to provide any significant seal beyond keeping dirt out. High side even more so. You need a high side R134 fitting that has it's own valve in it. They do make them and you'll likely have to find someone other than a chain parts store to get it. This is the only reliable high side valve fix. If you have the simple pass thru type adapter that comes with most conversion kits you'll have to be extremely careful removing it. Twist too hard and you'll snap off the whole thing or break the line. If you are running R12... try an angled valve extender that has it's own valve. That or use a METAL cap and AC rated thread sealer as soon as you are done charging. There's more about this in my cave. (interior dept.)

Oopss! I have no clue what happend to my reply on previous post. Let me bump. I wrote (didn't show up) that what he said is very true. My new valve didn't solve the problem and I have the problem on both of my Fieros. I would like info on where I can find any of those adapters. I have hoses for both R12 and R134A so I can use either so I can measure my high side. My search for them has been fruitless

I haven't been able to find them either. I wonder if they would have the metal caps at a plumbing store.....

I got the last valve/adapter at a local Parts Plus franchise. Sorry I don't have the part info anymore.

plumbing caps won't fit. wrong thread for the R12 fittings.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top of every forum page...)

Flimbob Go to Oreilly auto parts. Ask for Brass R134a adapters for your year fiero. They do require you to remove the old schrader valves to install them. be carefull putting them on as to not twist off the original port.

I just baught a set from O'reiley's Auto Parts. You have to remove the old valve steems and screw these on. You will loose any pressure or fluid if there is any in there. I don't have the receipt with me but I can get the part numbers tomorrow. They come with the high pressure (red) cap and the low pressure (blue) cap. The problem is you have to have a A/C shreader valve tool. The high side valve is larger than the low pressure side. The low pressure side steem is the same as a tire valve steem. The high side valve steem is bigger and a tire tool will not work. The two adaptor valves come indavidually so make sure you have two boxes. I'll see if I have a chance to post pics tomorrow.

Bob

Hey Stu..great minds think alike........just 2 min apart.

Thanks Guys! You are life savers!

Yup sure do. But here's where you left off. Remove the Low side valve and put the new adapter valve on. Then Use a cutting wheel to open up the slot in your tool to remove the High side one.

But seeing that you're in Plano, Come to the NTFC meetings on the Fourth Saturday @ 11am at Papa's BBQ on Loop 12 NW Highway Dallas. I'll bring my R134A equipment. Be sure to park on the far right hand side of the Pavilion so I have an outlet to plug in my Vacuum machine. Just let me know in advance so I can be sure to bring it all.

quote Originally posted by DIY_Stu: Flimbob Go to Oreilly auto parts. Ask for Brass R134a adapters for your year fiero. They do require you to remove the old schrader valves to install them. be carefull putting them on as to not twist off the original port.

There's no Oreilly in south FL Closest is at Jacksonville Can't find part in their online shop.

O'REILLY/MURRAY - Adapter Or Fitting
High side: 59986
Low side: 59976

quote Originally posted by flimbob: O'REILLY/MURRAY - Adapter Or Fitting High side: 59986 Low side: 59976

Thanks! This is great info for everybody Those are great because the are angled. I went to a different local auto parts (not a big chain) and finally found them. See the bottom pics of it. It also shows the tool for the shrader valve. That one I bought it at NAPA.

Oreillys part:


Another option: