There doesn't appear to be a low/high pressure cut off switch on the a/c system in my 68 Val.

I am currently upgrading the system to R134, with a parallel flow condenser and new hoses. Should I add a switch such as:

https://www.ackits.com/pc/57807-14MD/co ... off+Switch

to my build?

I was also thinking of putting an inline filter in the high side line. Thoughts?

Thanks much!

Chris E.

PS. Dan if you read this, I got a parallel flow condenser at your recommendation. I just finished the mounting bracketry last night. It is lookin' pretty good. Thank you!

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-76 Cordoba, 360 4bbl
-68 Valiant, 273 2bbl
-67 Dart /6 4bbl, Leaning Tower of Power!!!

A high-pressure cutoff switch certainly isn't a bad idea. It's a not-very-costly, not-very-difficult safety device to install. A low-pressure cutoff is less necessary given the Chrysler V2 compressor (I'm assuming) you're using. Don't forget to change the compressor seals, especially the shaft seal.

Filter's another easy/inexpensive good idea.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

1. Where is the best place to put an inline filter?
2. HERE is one from the same vendor. Any good?
3. I've seen "trinary" switches, combining the Hi/Low pressure safety switches with a fan switch coming on at about 250PSI. Good idea?

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

a guy on one of my other mp sites recommended this filter.

I'll have to call and see if there is a part # for the R2. This actually seems like the best place to filter to me. Just in case there is any crap already in the system.

http://www.airsept.com/index.php?loadmod=compressor

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-76 Cordoba, 360 4bbl
-68 Valiant, 273 2bbl
-67 Dart /6 4bbl, Leaning Tower of Power!!!

I am in the middle of a 134 retrofit myself. On our car I am using combination high / low switch and am using a receiver - dryer that has a switch port like the stock one did. It will just plug into the stock wiring that is already there and there will be no more clutter on any of the hoses.

A suction side screen is not a bad idea, and a high side filter between the receiver - dry and the expansion valve or orifice tube cannot hurt either.

One thing to be aware of is that it can be difficult to get a good seal with a compression fitting. They do make filters that will crimp into a hose.

Classic auto air has all this stuff as well.

Another good source I have use lately is Ray's Auto Air & Heat They have online ordering for just about any small part, fitting or hose you might need, are priced right and they ship quick. [/url]http://www.rayeveritt.com

Actually a high pressure cutoff switch is required by law (in the states), when retrofitting to R-134a.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

...really? Hadn't run into this. Which law says so?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I don't know one way or the other about it being the law, but a high side switch should probably be on every r134 system.

It is much easier to get the pressure too high than it is on an r12 system. When charging the system it can seem like it's almost there and then with the smallest addition of refrigerant the high side starts to shoot up. They can get right up in the high 300 range so much faster than an r12 system can. It's not as forgiving as an r12 system that will work great within a range of about a pound.

At least that's what I have noticed. The charge is just more critical, and on conversions it is really an educated guess just how much refrigerant to put in there. I would not add "a little extra" for good measure like one might with r12.

You may never need the high pressure switch, but if you do it can save the system and does make it safer too.