Expansion Valve [Archive] - Chevelle Tech

: Expansion Valve


von
Aug 6th, 12, 12:00 PM
Is it important to replace the expansion valve ('69 Malibu 350) when replacing the compressor and filter/dryer? I'm also converting to 134A. The system hasn't been used for about 7 years due to compressor knock but hs not been opened. I plan to disassemble and flush everything out. Will use new O rings too.

71hcc
Aug 6th, 12, 12:40 PM
I would advise it. When your already putting that much money in fixing your AC, I wouldn't depend on a 40 year old valve to work right.

jrs396
Aug 6th, 12, 5:08 PM
You need to have the POA valve recalibrated also for 134a

von
Aug 6th, 12, 5:21 PM
You need to have the POA valve recalibrated also for 134a
Yes I plan to do that too.

AscotBlue'71
Aug 6th, 12, 6:19 PM
classic auto air in tampa florida can test your exp valve along with recalibrating your poa for 134a. from what they tell me, an expansion valve is either good or bad....either it functions or its shot!

oman
Aug 6th, 12, 7:50 PM
Is it important to replace the expansion valve ('69 Malibu 350) when replacing the compressor and filter/dryer? I'm also converting to 134A. The system hasn't been used for about 7 years due to compressor knock but hs not been opened. I plan to disassemble and flush everything out. Will use new O rings too.

They work or they don't work....Classic can test as mentioned above. A point of info here. New exp valves are "one fits all" which means that the lines from the exp. valve to the POA are LONG. This allows one POA to fit many many applications.

How long you ask? Each of the lines can be 1.5 to 2 FEET long and come coiled up like a slinky. OE exp. valves with original length lines are NOT made any longer. The "one fits all" units look like S---T.

If you have an original and it works keep it or deal with the slinkies under the hood.

von
Aug 7th, 12, 11:49 AM
Thanks for the info. I'll probably send the POA and exp valve to Classic AA for testing and recalibrating. it looks like to change the filter/dryer the grille has to come out. Correct?

sbvelleman
Aug 7th, 12, 12:09 PM
You might also want to consider to update your condenser to a parallel flow type. The originals were designed for R-12. The modern parallel flow condensers are designed for R-134a. I remember seeing a post by another member, Robinls5 . He changed his condenser to the parellel flow and it made a big difference. If he doesn't chime in, try to e-mail or pm him for the specifics. Classic sells the parallel flow condensers for your '69.
Erich

Robinls5
Aug 7th, 12, 1:00 PM
Von:
Just some backround on my 70-SS Wagon with a Von-Jet carb. Dateline 2004--- Drained and flushed all the R-12. Rebuilt A-6 from Advance ( drain crankcase and fill with 134 oil). Did not mess with POA.
Charged with 134 or 75% of factory 60 oz= 48 oz.
Now A/C kinda works OK.
2007--Screw around with trying to adjust the POA. AT HOME, Drain fill Vac two or three times. A/C still kinda OK.......
2009--Send POA to Classic Air in Tampa,Fla.( 877-342-5526 Ron Mineo or Mike ) POA valve is now set for 134. A/C is getting better. At highway speeds A/C is fine. In the city, Still not up to Par. ( $15.00 shipping & $15.00 to adjust)
2011-- Talked to Ron M. at classic air. They now have a Paralell Flow Condenser for 70s. Paralell Flows are what ALL new 134 car/trks have.
Install new P.Flow Condenser from the Fla. guys, Also new hoses from Hinshaw, For the nice looks. Shot it with argon and test for leaks-A-OK Shot it up with 48 Ozs. of 134. HEY NOW !
Comming home from CB-12 It was 93-94 degrees in Kentucky around noon or one oclock. Started with the blower on " 4 " went to" 3 " then went to " 1 " then I cracked open a wing window.
Befor I left for CB-12 I charged it on a 90 degree day here in Pennsylvania, Wagon was outside in the sun, Black interior, A lot of CU. FT. of space inside......... I was getting 43-44 degrees from the center vent.
Also I have some new rubber bushings for the Condenser mounts, I bought a dozen. Got the info from Tom P.
Note: My expansion Valve and Evaporator have never been off the wagon. Bottom line .. I had the POA set for 134, New Condenser, New hoses ( for looks in 2012), A new dryer came with cond. I bought a Alum. 70 style dryer, Why? You can see it through the grill. Very KOLD air on the highway and in TRAFFIC.
Mech. gauge NEVER hits 200 with the A/C on. I let it sit and idle for around ten min. with the A/C on just to see if it would get hot.
If I can be of any help just ask. Talk to Ron or Mike. They know me very well.
Bob

Robinls5
Aug 7th, 12, 1:29 PM
NOTE:
Installing a new condenser on a 70, Piece of Cake, Yea Right !
1 - Remove the front bumper bolts, Crack the rear bolts, Do not forget Parking light wires. Slide it forward, Now just roll the bumper down and let it rest on a towel
2 - Remove fender extensions--Remove grill--Remove hood latch Assmb.
Remove ( body colored filler pan.)
3 - Now the Cond is ready to exit. Remove the lines,dryer and Pi$$ and Moan a bit.( NOTE: the nuts on the rubber condenser support bushings may twist out of the rubber) E-Mail me , I bought a dozen new ones $1.17 each or $10.00 each from a Chevelle outlet. ( you need four )
4 - Condenser must go forward about 3", Then it can be removed.
5 - This is a job that sounds E-Z, If your not doing it!
Bob

von
Aug 7th, 12, 2:52 PM
Thanks for the info Bob. I'm going to try the stock condenser for now. Don't want to add another $200+ for a parallel flow cond on top of all I'm spending for rebuilt compressor, dryer, 134, flush, etc., plus pay someone to draw a vacuum and charge it.

oman
Aug 7th, 12, 3:02 PM
Thanks for the info Bob. I'm going to try the stock condenser for now. Don't want to add another $200+ for a parallel flow cond on top of all I'm spending for rebuilt compressor, dryer, 134, flush, etc., plus pay someone to draw a vacuum and charge it.

Just a thought here on the condenser. If you do it now you avoid the cost one charge and one evac of the system. Not sure what that is gonna cost you but going with the condenser now saves one pass at that charge work. That is directly deductible from the condenser cost which I think is considerably less than the $200 you mention.

Robinls5
Aug 7th, 12, 7:06 PM
A new R-134-P.Flow Condenser from the Fla. Guys comes with a Dryer, New Alum. crossover tube from dryer to the other side, dryer brackets, and all " O " rings.
Cost is around $ 300.00. I did not want to do it, BUT...... In traffic the A/C with the stock 3/8" tubes stacked two wide and 17 high. The cooling falls off big time almost to " Nutten Honey ".
The P. Flow condenser has 45 rows.
Trivia: R-134 generates more heat than R-12, So it needs a lot more air ( And SURFACE AREA ) to cool it down. More trivia, My compressor would spit out a little oil using the old condenser " on the hood & fender well "
New condenser no oil slinging out, I believe the whole system is running cooler.
I do have a plus for the old Org. condenser,,,, If you keep moving at 45 MPH or better= YES you will be KOOL.
I do have a 1970 O.E.M. condenser that was working fine when removed.
Bob

oman
Aug 7th, 12, 7:28 PM
A new R-134-P.Flow Condenser from the Fla. Guys comes with a Dryer, New Alum. crossover tube from dryer to the other side, dryer brackets, and all " O " rings.
Cost is around $ 300.00. I did not want to do it, BUT...... In traffic the A/C with the stock 3/8" tubes stacked two wide and 17 high. The cooling falls off big time almost to " Nutten Honey ".
The P. Flow condenser has 45 rows.
Trivia: R-134 generates more heat than R-12, So it needs a lot more air ( And SURFACE AREA ) to cool it down. More trivia, My compressor would spit out a little oil using the old condenser " on the hood & fender well "
New condenser no oil slinging out, I believe the whole system is running cooler.
I do have a plus for the old Org. condenser,,,, If you keep moving at 45 MPH or better= YES you will be KOOL.
I do have a 1970 O.E.M. condenser that was working fine when removed.
Bob

Bob

My mistake on the cost of the condenser. The "universal" / "fits-all" condensers are in the $150 range but you of course have to make your own brackets. I guess I cannot deny Classic money on the effort they expended to make the universal condenser into a bolt in arrangement like the one you have.