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AC capacity and retrofit questions by gtemplet
Started on: 06-11-2014 10:19 AM
Replies: 11 (570 views)
Last post by: gtemplet on 06-13-2014 10:14 AM
gtemplet
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Report this Post06-11-2014 10:19 AM Click Here to See the Profile for gtempletSend a Private Message to gtempletEdit/Delete MessageReply w/QuoteDirect Link to This Post
Finishing up an engine rebuild right now so my AC has been open for months and it was empty when I disassembled it (car has sat for 12+ yrs). I found a local guy who still does R12 for $100/lb. I'm wondering how much R12 will be needed? He told be 2lbs is $200 and if I happen to need 2.1lbs it'll be $300. Of course I won't do anything til after it is leak checked. Also I read on the forum that the accumulator is only good for about 7 yrs, should I replace it? And if I do replace it should I go ahead and retrofit to 134a? Now if I do retrofit I read on the forum that if I have a DA6 compressor (87 SE V6) I should change it out for HR6 compressor. For those who haven't changed compressors did the DA6s hold up? Thanks for looking any and all help is appreciated.
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TopNotch
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Report this Post06-11-2014 10:52 AM Click Here to See the Profile for TopNotchClick Here to visit TopNotch's HomePageSend a Private Message to TopNotchEdit/Delete MessageReply w/QuoteDirect Link to This Post
Replace the accumulator, orifice tube, and compressor. Add the retrofit R134a fittings.
If there is crud in the old orifice tube, you may need to flush the system.
Replace or adjust (if you know how) the cycle switch (adjusted for R134a).
Add 4 oz. of ester oil in the new accumulator, and another 4 oz. in the compressor before re-assembly.
After re-assembly, pull a vacuum on the system for at least 1/2 hour, and see if it holds the vacuum with the pump off.
Charge the system with 2 cans of R134a. The vacuum will pull in enough R134a for the system to start working so you can add the rest.

[This message has been edited by TopNotch (edited 06-11-2014).]

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gtemplet
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Report this Post06-11-2014 12:46 PM Click Here to See the Profile for gtempletSend a Private Message to gtempletEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks TopNotch, I've been searching the retrofit how to' s and that is the best answer so far. I'll take your answer as you think it's better to convert over to 134a. Has anybody used the Fiero store retrofit kit? Any opinions on it? Any opinions on this kit from rockauto, the accumulator looks a little different but I figure it's just a generic picture.
http://www.rockauto.com/cat...49152,parttype,17507

[This message has been edited by gtemplet (edited 06-11-2014).]

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fierofool
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Report this Post06-11-2014 04:42 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
I've had several converted over to 134a simply by replacing all the O rings and flat washer seals to 134a friendly stuff, evacuating the system and filling with new oil and 134a. I've been running a DA6 compressor for years without any problems. Wiring and switching to the back of the HR6 compressor is a little different from the HR6.

That retrofit kit is good because someone else has done all the legwork to put it together for non-AC folks like you and I. TopNotch has good advice on putting in a new receiver-dryer and orifice tube. The instructions with the receiver-dryer should tell you how much oil to put into it. Generally it's 4 oz. like TopNotch said.

The original Fiero system required about 32 oz. of R12 so you're looking at nearly $300 in refrigerant. The R 134a can be had for $10 a can at your local discount store like Dollar General, Dollar Tree or similar stores. Because R134a has a higher expansion value, Fiero gurus have told us that we only need 25.6 oz. so the 24 oz. will work great. That's what I have in my system. I just wasn't going to tap another can for 1.6 oz. and my system cools very well, even here in Georgia.

If the car hasn't been driven around with the system open and the compressor and the AC line has been protected from dirt and trash entering it, you may be able to use the original compressor. You can purchae a 134a cycle switch that screws directly into the receiver-dryer or go to your local pick a part yard and grab one from a wrecked car. They're relatively cheap at the auto parts stores. Advance Auto Parts has them for $20. http://shop.advanceautopart...22|L2*15015|L3*15831

If you replace the receiver-dryer, remove the old one first and take it along with you for comparison. Some aftermarket units have the low side charge port on the back of the unit so you can't get your charge hose onto it.
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gtemplet
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Report this Post06-11-2014 06:04 PM Click Here to See the Profile for gtempletSend a Private Message to gtempletEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks Fierofool, I think with you and Topnotches answers I'm going the 134a route. I don't know if I should roll the dice with my compressor. If it goes bad then I'm out the price of the refrigerant (no big deal) and the fun to change the compressor while the engine is in the car (which would suck).If it works then I saved a couple hundred $$$$. Might be a coin flip. While price shopping for the accumulator I have found some that are half the price of the Fiero stores, nothing at all against them they have been a help to me, but the cheaper ones do not look the same in the pictures as what I have. Does anybody have a part number, brand name or where they got theirs at? FS is $65. I will put a quality product in over a cheap product but if I can get quality cheap even better.
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Report this Post06-11-2014 08:39 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
Four Seasons or Ready Aire are common replacement heating and cooling parts. Here's a Four Seasons unit. Usually the cost is not more than about $45 at local auto parts stores.
It plugged in 87GT because that's one of my cars but it fits 85-88's.
http://www.stockwiseauto.co...GL874CFVFp7Aod2l4AAQ
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josef644
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Report this Post06-12-2014 11:34 AM Click Here to See the Profile for josef644Click Here to Email josef644Send a Private Message to josef644Edit/Delete MessageReply w/QuoteDirect Link to This Post
Less than $20.00 on RockAuto. I looked up one for my 88. But all Fieros used the same accumulator.
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KissMySSFiero
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Report this Post06-12-2014 12:43 PM Click Here to See the Profile for KissMySSFieroClick Here to Email KissMySSFieroSend a Private Message to KissMySSFieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fierofool:

You can purchae a 134a cycle switch that screws directly into the receiver-dryer or go to your local pick a part yard and grab one from a wrecked car. They're relatively cheap at the auto parts stores. Advance Auto Parts has them for $20. http://shop.advanceautopart...22|L2*15015|L3*15831



What does this switch do? I assume it cycles the compressor at different pressures better suited for R134.
Is it a direct swap? I'm assuming it replaces the one on the accumulator(88 V6)

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SSFiero@Aol.com

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rogergarrison
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Report this Post06-12-2014 01:02 PM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just my opinion having had a lot of cars with both R12 and 134. Id pay the price and refill a good system with R12. You get away with 134 much better in such a small car though. R12 seems to cool a good 10*-15* cooler to me than 134. My new Magnum barely made a hot summer day bearable...never cool.
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Report this Post06-12-2014 03:28 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by KissMySSFiero:


What does this switch do? I assume it cycles the compressor at different pressures better suited for R134.
Is it a direct swap? I'm assuming it replaces the one on the accumulator(88 V6)



You're correct. It cycles the compressor at the correct pressures for the R134a. I'm not sure how those pressures compare to the R12. The unit I posted is a direct swap, plug and play, for the one used for R12 in the Fiero. That black sleeve on the switch is simply a shield to protect the 2 male terminals during shipping. It pulls off to allow the harness to be plugged on. It seems that all manufacturers show the switch with that protective cover. I think it's sometimes deceptive, making people reject it on appearance.
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Report this Post06-12-2014 11:10 PM Click Here to See the Profile for RWDPLZClick Here to visit RWDPLZ's HomePageSend a Private Message to RWDPLZEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fierofool:


You're correct. It cycles the compressor at the correct pressures for the R134a. I'm not sure how those pressures compare to the R12.


25psi for R-12, 21psi for R-134A. The original switch has an adjustment screw between the terminals, you can use a gauge set to check the pressures and adjust it, or buy a switch already preset for R-134A.

Original Fiero R-12 capacity was 2.5lbs. Oil capacity is 8 oz of 525 viscosity mineral oil.
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gtemplet
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Report this Post06-13-2014 10:14 AM Click Here to See the Profile for gtempletSend a Private Message to gtempletEdit/Delete MessageReply w/QuoteDirect Link to This Post
Josef thanks for the reply, I did see those at Rockauto, I have used them for numerous parts. The Four Seasons PN #33181 ($20.79) at Rockauto, I found this one at Advanced Auto: Toughone/Factory Air PN# t33181 (19.99). Except for the 't' same part number, hmmmm.

Roger thanks for the response, you are probably the only reason I'm still considering R12, I've seen your responses in other threads and respect your opinion.

RWDPLZ great info, I pulled the switch off and was wondering if that was an adjustment screw. I might try to adjust it now that I got the pressure set point. Thanks for the numbers and capacity.

The switch Fierofool mentioned is now $14.99 at Advanced Auto. Thank again everybody.
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