C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

A/c

Thread Tools
 
Search this Thread
 
Old Jul 20, 2016 | 08:50 PM
  #1  
Bond007's Avatar
Bond007
Thread Starter
Racer
Supporting Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
Default A/c

So 2years ago I had my A/C converted to 134, I tried using it today and it would not engage figured it was out of refrigerant possible leak somewhere maybe so went to my garage guys to get a charge. When they started to hook up their hoses they found that the high side valve was installed on the low pressure and that they did not want to charge it and take a chance on ruining the compressor. Why would the fellow who converted over put the high side valve on the low side? Can someone shed some light on what do I do next
Thank You
Reply
Old Jul 20, 2016 | 09:10 PM
  #2  
'75's Avatar
'75
Le Mans Master
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
Default

I could be as simple as putting the right retro-fit coupler on it. Most can be removed without losing the charge because it just screws onto the r12 port and uses the same schrader valve. Can you take some pictures and post them?
Reply
Old Jul 20, 2016 | 09:12 PM
  #3  
billschroeder5842's Avatar
billschroeder5842
Zen Vet Master Level VII
Supporting Gold
Veteran: Navy
Liked
Loved
Community Favorite
 
Joined: Mar 2016
Posts: 5,213
Likes: 1,173
From: Southlake, TX
Default

Year please?

Was it working before or if ever?

Hard to believe that backwards would work as the refrigerant flow just would not work.

Is it possible that (if your system worked int he past) that your new team got mixed up?
Reply
Old Jul 20, 2016 | 09:13 PM
  #4  
jim in oregon's Avatar
jim in oregon
Burning Brakes
 
Joined: Oct 2015
Posts: 781
Likes: 113
Default

Originally Posted by Bond007
So 2years ago I had my A/C converted to 134, I tried using it today and it would not engage figured it was out of refrigerant possible leak somewhere maybe so went to my garage guys to get a charge. When they started to hook up their hoses they found that the high side valve was installed on the low pressure and that they did not want to charge it and take a chance on ruining the compressor. Why would the fellow who converted over put the high side valve on the low side? Can someone shed some light on what do I do next
Thank You
Probably no recourse from whomever hosed you..(sorry I couldn't resist)If your reg shop has folks who are knowlgable-trained certified on A/c system..Find an A/C SHOP who DOES have the people..
..Have them pop the hood and look it over..specifically..belts/ hoses and fittings obvioius
leaks..not sure which upgrade kit was used but SEE if a A/C tech spots the SCHradwer valve-hose stuffJim
Don't tell them anything at this point..Jim

Last edited by jim in oregon; Jul 20, 2016 at 09:15 PM.
Reply
Old Jul 20, 2016 | 09:38 PM
  #5  
cobrachuck's Avatar
cobrachuck
Pro
Veteran: Army
20 Year Member
Liked
Community Favorite
 
Joined: Mar 2006
Posts: 527
Likes: 84
From: SW Ohio
Default

I agree with Jim above
Get a 2nd opinion on this it does not sound right. Do not give out history.
Chuck
Reply
Old Jul 20, 2016 | 09:51 PM
  #6  
carriljc's Avatar
carriljc
Le Mans Master
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2001
Posts: 6,656
Likes: 1,357
Default really - post some pictures

as mentioned earlier iy could be as easy as swapppping adapter fittings



Originally Posted by Bond007
So 2years ago I had my A/C converted to 134, I tried using it today and it would not engage figured it was out of refrigerant possible leak somewhere maybe so went to my garage guys to get a charge. When they started to hook up their hoses they found that the high side valve was installed on the low pressure and that they did not want to charge it and take a chance on ruining the compressor. Why would the fellow who converted over put the high side valve on the low side? Can someone shed some light on what do I do next
Thank You
Reply
Old Jul 20, 2016 | 09:59 PM
  #7  
jim in oregon's Avatar
jim in oregon
Burning Brakes
 
Joined: Oct 2015
Posts: 781
Likes: 113
Default

Originally Posted by Bond007
So 2years ago I had my A/C converted to 134, I tried using it today and it would not engage figured it was out of refrigerant possible leak somewhere maybe so went to my garage guys to get a charge. When they started to hook up their hoses they found that the high side valve was installed on the low pressure and that they did not want to charge it and take a chance on ruining the compressor. Why would the fellow who converted over put the high side valve on the low side? Can someone shed some light on what do I do next
Thank You
ONE QUESTION THAT occurred to me after my last post..
CURIOUS IF when the uprgade was done 2 YRs back????DID the system function and cool properly after the upgrade according to work done and to your satisfaction/..Shop still in business..IF SO..contact them and ask IF THEY would look at the retro A/C YOU BOUGHT FROM THEM BACK Then to see what the problem is..You have paperwork from the past..which IF they are repuarable should help..Jim
FWIW my fact A/C was converted last year to R134A..
It finally function properly..AFTER I PULLED CONSOLE BOARDS OFF,GLOVE BOX INTERIOR OUT and ADJUSTED the cable turnbuckle so when cold is chosen the bypass valve colses to provide vacuum to close the underhoot heater solenoid S IT simultaneously open ductwork doors for cold air or mix or vent...Another thread..Jim
Reply
Old Jul 20, 2016 | 10:04 PM
  #8  
jim in oregon's Avatar
jim in oregon
Burning Brakes
 
Joined: Oct 2015
Posts: 781
Likes: 113
Default

ONE final Q ?? before I STOP,,
DID YOU AND OR ANOTHER person qualified i'd hope.Do the conversion yourselves.?
HARD to imagine any cert A/C tech not knowing hi from low side Jim
.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-1

2027 Corvette vs The World: Every Model vs Closest Competitor

 Joe Kucinski
story-2

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-3

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
story-4

2027 Corvette Buyer's Guide: Everything You Need to Know!

 Joe Kucinski
story-5

10 Things C8 Corvette Owners Hate (But Won't Tell You)

 Joe Kucinski
story-6

10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

 Brett Foote
story-7

Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

 Joe Kucinski
story-8

Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

 Michael S. Palmer
story-9

5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

 Joe Kucinski
Old Jul 21, 2016 | 07:22 AM
  #9  
ykf7b0's Avatar
ykf7b0
Racer
 
Joined: Aug 2014
Posts: 479
Likes: 93
From: Tennessee
Default

Is it even possible to install high side fitting to low side port?
Reply
Old Jul 21, 2016 | 07:49 AM
  #10  
Bond007's Avatar
Bond007
Thread Starter
Racer
Supporting Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
Default

Yes the system did work after conversion. After work last night went to parts store and they suggested another shop in town that handles a lot of A/C work so I made an appointment for Monday. Will let all know what was found and what was done to solve the issue, the shop that did the conversion is on vacation so I can't ask anyone till next week, anyway will now get another set of eyes on it.
Thank You for all the input.
Reply
Old Jul 21, 2016 | 09:48 AM
  #11  
gerry72's Avatar
gerry72
Safety Car
20 Year Member
 
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Default

Originally Posted by ykf7b0
Is it even possible to install high side fitting to low side port?
Yes, it is. R12 ports are the same both high and low. There is one big issue with screwing the suction side port on the high side: you can't charge they system with one of those parts store recharge kits because you can't charge the system from the high side.

You could still charge the system with a gauge set. All you do is open the manifold from the high side to feed the flip-flopped ports. Of course, you can't get a good read on the evaporator performance from the high side gauge, but you can put refrigerant in the system.
Reply
Old Jul 21, 2016 | 10:04 AM
  #12  
71 Green 454's Avatar
71 Green 454
Le Mans Master
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2006
Posts: 6,390
Likes: 1,225
From: Tampa Florida
Default

Originally Posted by gerry72
Yes, it is. R12 ports are the same both high and low. There is one big issue with screwing the suction side port on the high side: you can't charge they system with one of those parts store recharge kits because you can't charge the system from the high side.

You could still charge the system with a gauge set. All you do is open the manifold from the high side to feed the flip-flopped ports. Of course, you can't get a good read on the evaporator performance from the high side gauge, but you can put refrigerant in the system.


But, couldn't you just temporarily switch the high/low hoses on the manifold gauge set to use the low side gauge?



Last edited by 71 Green 454; Jul 21, 2016 at 10:07 AM.
Reply
Old Jul 21, 2016 | 10:10 AM
  #13  
gerry72's Avatar
gerry72
Safety Car
20 Year Member
 
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Default

Originally Posted by 71 Green 454


But, couldn't you just temporarily switch the high/low hoses on the manifold gauge set to use the low side gauge?

Well, yeah. Duh, just didn't think of the easy fix.
Reply
Old Jul 22, 2016 | 09:32 AM
  #14  
Bond007's Avatar
Bond007
Thread Starter
Racer
Supporting Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
Default

As I mentioned earlier will be in the shop Monday with the car however, curious, can anyone show me where the low side A/C port is located on my 76?
Thank You
Reply
Old Jul 22, 2016 | 09:55 AM
  #15  
gerry72's Avatar
gerry72
Safety Car
20 Year Member
 
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Default

Not exactly but I can tell you which line you're looking for when tracing the charge port. The suction (low) line is always the larger of the two A/C lines out of the evaporator and runs to the compressor. The reason for this is the suction (low) line is carrying the evaporated vapor back to the compressor and has a much larger volume than the liquid line, which feeds refrigerant to the evaporator. The discharge (liquid) line out of the compressor will always run to the condenser (the radiator thing) at the front of the car and always enters the condenser from the top. Th high side line gets much smaller when it leaves the condenser at the bottom since it is (we hope) carrying the refrigerant condensed into a liquid. In C3's the ports are usually on the manifold bolted to the compressor. But even if it is not like that on your car, you now know how to identify the suction (low) and high side.
Reply
Old Jul 22, 2016 | 10:43 AM
  #16  
71 Green 454's Avatar
71 Green 454
Le Mans Master
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2006
Posts: 6,390
Likes: 1,225
From: Tampa Florida
Default

Originally Posted by Bond007
As I mentioned earlier will be in the shop Monday with the car however, curious, can anyone show me where the low side A/C port is located on my 76?
Thank You
If yours looks like this one, the blue cap is the low side and the red cap is the high side.


Reply
Old Jul 22, 2016 | 12:18 PM
  #17  
Bond007's Avatar
Bond007
Thread Starter
Racer
Supporting Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2000
Posts: 416
Likes: 4
From: Iron Mountain,Michigan
Default

Thank you very much 71 green 454 that is exactly what I am looking for. Yipee Beautiful engine detail I'm jealous.
Reply
Old Jul 22, 2016 | 01:18 PM
  #18  
71 Green 454's Avatar
71 Green 454
Le Mans Master
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2006
Posts: 6,390
Likes: 1,225
From: Tampa Florida
Default

Originally Posted by Bond007
Thank you very much 71 green 454 that is exactly what I am looking for. Yipee Beautiful engine detail I'm jealous.
Glad it helped....that engine is not mine, I just found it for reference.
My '71 is a BB.


Reply

Get notified of new replies

To A/c





All times are GMT -4. The time now is 06:33 AM.

story-0
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-1
2027 Corvette vs The World: Every Model vs Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-20 17:58:41


VIEW MORE
story-2
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-3
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-4
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE
story-5
10 Things C8 Corvette Owners Hate (But Won't Tell You)

Slideshow: 10 things C8 Corvette owners hate, but won't tell you.

By Joe Kucinski | 2026-04-01 18:36:07


VIEW MORE
story-6
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

Slideshow: Should you add one of these incredible Corvettes to your garage?

By Brett Foote | 2026-04-01 18:14:05


VIEW MORE
story-7
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

Slideshow: Every Corvette Grand Sport explained

By Joe Kucinski | 2026-03-26 07:13:44


VIEW MORE
story-8
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

Slideshow: Breaking down the 2027 Grand Sport, Grand Sport X, Stingray, and LS6 V8.

By Michael S. Palmer | 2026-03-26 13:48:45


VIEW MORE
story-9
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

Slideshow: 5 reasons bad drivers crash sports cars & 5 ways to avoid a costly shame!

By Joe Kucinski | 2026-03-25 16:32:55


VIEW MORE