Air conditioning issue

GHOSTXR7

Registered User
I recently installed a new compressor, accumulator, and condenser in my 90xr7. I have a couple issues with the high side pressure climbing past 300 and damn near over 400 head pressure and i am stuck with why this is happening. One reference i will make is that the stock condenser looks much larger than the condenser i purchased from auto zone i know can me for that. My thoughts that this could be the culprit but i am not sure. Any thoughts will be appreciated
 
Re

Also i did convert the system to r134. The freon amount for the r12 system stated to put 40 ounces into the system but when converting over to r134 freon that amount goes to 30 ounces and that is what i did. 1 pound 14 ounces. I just dont know
 
Did you pull a vacuum ? Did you blow out oil from the evaporator, condensor?
Did you replace the oriface tube line? If none of these were done they need to be. Also the fan was running too? If you do this test again get it outside & spray the condensor with the hose & while its running & see if the high side drops. Doing AC work does require steps that must be done.
 
I bet the orifice in the liquid line is plugged and the line needs to be replaced.

IF you do - from my experience, don't use a Four Seasons line.

The AC/Delco I was using until ITS orifice tube plugged (compressor did a Black Death on me) held onto the evaporator just fine. The new Four Seasons? Likes to blow off if the motor is nice and toasty-warm. Sigh.

Motorcraft if you can possibly afford it. If not, consider a replacement orifice tube - the kit is about $25 from Rock Auto, plus about $1 for the tube (!!)

RwP
 
guys... an otube is an otube is an otube... If your compressor failed, you need to clean out the debris otherwise it will settle into the otube screen regardless of the manufacturer. If your liq line is new, your compressor, accumulator and condenser are new, you've got what you need to put a clean system together.

It sounds more like the fan is not running if the high pressure is that high. The low side should be cycling in the mid-low 20s. But to get lower than 30psi you'll need to tweak the pressure switch a bit.
 
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Ok well i have put in a new compressor, accumulator, and condenser. I did not do a liquid line but i blew it out. Same as the evaporator. My fan is running though. My readings are 35 on the low side and it starts at 275 and climbs its way up to 400 which i know is never any good. Now i may sound dumb but with a liquid line i didnt think u would have to put an o-tube in it. One more thing though the oe condenser that i took out and the one i put in looks nothing of the same. As you all know the condenser coming out is a kinda thick almost radiator thick but the one i put in is thin and i am wondering if that has anything to do with it
 
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Yessir i did pull a vacuum and it held really well. I did get some oil out of the compressor condenser and accumulator. It said the system holds 7ounces so i put 1 in the drier, 3 in the compressor and 2 in the condenser leaving room for whatever may be in the evap.
 
With the drop, I can say that your orifice tube is working pretty much.

It sounds almost like it's over charged to me.

Mine, I can't get a full 80% 0f the charge in (33 oz for R12, logically I should have about 26.4 oz for my 80% mark, I usually have to stop at about 22 or 23 oz) so there's that possibility.

It could be the condenser is smaller than your old one, in which case, it won't take as much charge.

Also, if there was any oil left in the system when you added, you may be over oiled, which will ALSO reduce total freon capacity.

What's the ambient (at the condenser!) when you're seeing the pressures go up to close to 400 PSI? And if you spray the condenser with water, does the pressure go down?

RwP
 
Mine, I can't get a full 80% 0f the charge in (33 oz for R12, logically I should have about 26.4 oz for my 80% mark, I usually have to stop at about 22 or 23 oz) so there's that possibility.
Thats about right. Its hard to push more than 32 oz into it to begin with AND keep your high side below 400. Also, the original R12 amount is 40oz. 80% ends up being 32oz.

What's the ambient (at the condenser!) when you're seeing the pressures go up to close to 400 PSI? And if you spray the condenser with water, does the pressure go down?

RwP
FWIW, I let my high side go into the high 300s on a 100+ degree day as I want COLD air and if it takes 380 to get it... it takes 380 to get it. :rolleyes:
 
As you all know the condenser coming out is a kinda thick almost radiator thick but the one i put in is thin and i am wondering if that has anything to do with it
Thinner is better. You need a new liquid line if your compressor died. You can't really back flush that thing very well. You may get some stuff out the front end, but there's still small metal slivers in there which will shorten compressor life. The lines are cheap.
 
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Yes i think that is the problem. What i did is ordered up a liquid line. I am going to install that and afterward since i have already retrofitted to r134 how much freon would be the correct amount. I have been doing the conversion with 75% and from 40 ounces of r12 i get 30 ounces of r134 which is 1 pound 14 ounces so should i go less than that or is that the proper amount
 
High

Fwiw means what lol. And with high 380 head pressure isnt that close to blowing seals and such. Ive always thought that head pressure that high can be detrimental to a compressor
 
And with high 380 head pressure isnt that close to blowing seals and such. Ive always thought that head pressure that high can be detrimental to a compressor
Nah.. 380.. just warming up. :D I did a whole system replacement back in 2002 on my white car for r134a. Its been running mid 300s for all that time and has lasted longer than the OEM equipment did.
 
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Ok cool cool well what i am going to do is install the liquid line and see what happens from there which i think will be the fix dat is needed. Mid 300 and everything still blows cold hunh well that taught me something new. Thanks a million the input is very appreciated
 
You want to fill it until the high side reads 2.5 times ambient air temp. 100 degree air outside 250 line pressure. Works well.
 
Thats about right. Its hard to push more than 32 oz into it to begin with AND keep your high side below 400. Also, the original R12 amount is 40oz. 80% ends up being 32oz.

The sticker on my radiator cross piece says "33 Oz, 1.02 KG".

Yours may be 40oz, but mine is 33 factory.

(of R12 that is.)

RwP
 
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