Pontiac

Pontiac problems? Ask a mechanic for answers ASAP

Ask an Expert,
Get an Answer ASAP!

I have a 1978 Pontiac Firebird fully converted to R134a.

Customer Question
Prior mechanic installed new compressor...
I have a 1978 Pontiac Firebird fully converted to R134a. Prior mechanic installed new compressor with only the 3 ounces in the compressor. It takes 8 ounces. So, first compressor fried. I replaced the compressor (with the proper amount of PAG). But, I have 2 issues.
I can draw down a -30 vacuum and the vacuum holds if you come back in an hour and look at the gauges. But, if you leave it over night, the vacuum does not hold that long. It goes from -30 to 0 sitting over night.
It will not take a charge no matter what I do. I've tried 3 different sets of manifold gauges. 2 different can piercing handles. 2 different brands of refrigerant. The can does not have enough pressure to push any refrigerant in and the AC system won't suck any in.
If the clutch needs to engage to draw in refrigerant but the clutch won't engage without enough refrigerant is a big old catch 22. Do I get around that by jumpering the pressure switch to engage the clutch?
Submitted: 8 months ago.Category: Pontiac
Show More
Show Less
Ask Your Own Pontiac Question
Answered in 3 minutes by:
8/5/2017
Pontiac Mechanic: Gary, ASE Certified Technician replied 8 months ago
Gary
Gary, ASE Certified Technician
Category: Pontiac
Satisfied Customers: 1,648
Experience: Senior Technician
Verified

Hello! My name is Gary.
Welcome to JustAnswer.
I'm reviewing your question now, and will post back with a reply shortly.

Ask Your Own Pontiac Question
Pontiac Mechanic: Gary, ASE Certified Technician replied 8 months ago

Hi Matthew,

Are you pulling vacuum, and then charging?

It won't take the full charge if there isn't a vacuum to start with.

Gary

Ask Your Own Pontiac Question
Customer reply replied 8 months ago
Pulling down a -30 vacuum for 45 minutes using a JB Industries 2 cycle 6cfm pump
Customer reply replied 8 months ago
Pulling a -30 vacuum for over 30 minutes.
Customer reply replied 8 months ago
Using a JB Industries 2 cycle vacuum pump. All equipment is top of the line. No auto part store garbage.
Customer reply replied 8 months ago
Pulling vacuum with H and L open. Close H and L. Turn off vacuum pump. Holding at -30. Disconnect yellow from pump to refrigerant. Open refrigerant. Purge the line. Start car. Turn on AC. Open L on manifold. And nothing. It won't take a charge.
Customer reply replied 8 months ago
Hook up high and low sides. Close both high and low. Turn on vacuum pump. Open high and low. Vacuums down to -30 for half an hour. Close high and low. Turn off vacuum pump. Unhook yellow from vacuum and hook it up to refrigerant. Open refrigerant. Purge the line. Turn on car. Turn on AC. Open low side. And - NOTHING!
Pontiac Mechanic: Gary, ASE Certified Technician replied 8 months ago

Can you charge it on the high side before starting the engine?

Ask Your Own Pontiac Question
Customer reply replied 8 months ago
Nope.
Customer reply replied 8 months ago
Nope. I tried.
Customer reply replied 8 months ago
If the clutch must engage to draw in refrigerant - but the clutch won't kick on until it has enough refrigerant, that means you will never be able to charge it.
Customer reply replied 8 months ago
If I jumper the pressure switch to force the clutch to engage, will that then draw in the charge?
Customer reply replied 8 months ago
Also, the system will hold vacuum at -30 for an hour long sit and check. But, it won't hold it overnight. Is that normal not to hold it that long? Or does that mean I have a small 24 hour leak?
Pontiac Mechanic: Gary, ASE Certified Technician replied 8 months ago

Did you flush the whole system after the compressor failure, and replace the filter?

You shouldn't charge any system from empty on the low side these days.

You must have a blockage if it won't take the charge on the high side.

I wouldn't worry about not holding vacuum over 24 hours, could be part of your charging station.

Ask Your Own Pontiac Question
Customer reply replied 8 months ago
If I vacuum down to -30 and come back in an hour, it will still be holding at -30. But, if I let it sit overnight, it loses the vacuum back up to 0. Is that normal? Probably leaking from the quick connects on the ports? Or does that mean I have a small 24 hour leak?
Customer reply replied 8 months ago
I replaced the compressor, orriface tube and accumulator. Put 4 ounces of PAG 46 in the compressor and 4 ounces in the accumulator. I did not flush it because it was just flushed 200 miles ago when the first compressor was installed.
Customer reply replied 8 months ago
Can I charge it on the low side if I jumper the pressure switch to engage the clutch? Or will that fry the compressor?
Customer reply replied 8 months ago
I correct that you charge on the low side with the engine and air running or the high side with the engine off. But never on the high side with the engine and AC running?
Pontiac Mechanic: Gary, ASE Certified Technician replied 8 months ago

If it is still holding -30 after 1 hour, I'd say put the gas in.

Every car I do, I pull vacuum, short wait, then charge via the high side with the specified weight of R134a.

You can suck it on the low side, if you jumper the pressure switch, engine running.

Charging via the high side is engine off only.

Gary

Ask Your Own Pontiac Question
Customer reply replied 8 months ago
Got it. If I jumper the pressure switch to engage the clutch, will I fry the clutch or compressor? Or is it safe for a few minutes?
Customer reply replied 8 months ago
Do the auto part store 12 ounce cans of R134a have enough push and pressure to charge on the high side through the AC manifold? I guess I'll try high side engine off first. Then I'll try low side engine on and jumper the clutch.
Pontiac Mechanic: Gary, ASE Certified Technician replied 8 months ago

The vacuum generated while evacuating should draw in sufficient on the high side, engine off.

If you need to, you can then suck in on the low side, engine running.

The average systems I deal with take about 25 ounces, 700 grams.

Gary

Ask Your Own Pontiac Question
Pontiac Mechanic: Gary, ASE Certified Technician replied 8 months ago

Hi Matthew,

I hope this had made sense for you.

All the best.

Kind regards

Gary

Ask Your Own Pontiac Question
Pontiac Mechanic: Gary, ASE Certified Technician replied 8 months ago

Hello again,

Do you need any further help?

I hope my advice has been of assistance to you.

Kind regards

Gary

Ask Your Own Pontiac Question
Was this answer helpful?
Ask Gary Your Own Question
Gary
Gary
Gary, ASE Certified Technician
Category: Pontiac
Satisfied Customers: 1,648
1,648 Satisfied Customers
Experience: Senior Technician

Gary is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

GM Tech (Cam)

GM Tech (Cam)

Pontiac Technician

2,379 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Dave Nova

Dave Nova

Pontiac Technician

2,014 satisfied customers

ASE Master Certification. GM World Class Certification

Gary

Gary

Pontiac Technician

1,436 satisfied customers

15 years GM master tech/15 years ASE master

Ron Z.

Ron Z.

- Pontiac Tech -

761 satisfied customers

18+yrs experience. State Inspector and Pontiac Diagnostics

Don - Mo Lurch

Don - Mo Lurch

Pontiac Mechanic

551 satisfied customers

GM, Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.

John

John

GM FACTORY CERTIFIED TECHNICIAN

514 satisfied customers

ASE A1-A8 w/L1 GM master technician.Factory certified/40 years experience

car tech

car tech

ASE Certified Technician

446 satisfied customers

25 years master tech and shop owner

< Previous | Next >

Related Pontiac Questions
Signal light problem. Signal light. 2008 pontiac montana. I
i replaced all bulbs checked all fuses and ground wires … read more
GM Tech (Cam)
GM Tech (Cam)
Pontiac Technician
Vocational, Technical or Trade Scho
2,379 satisfied customers
I already submited 1 hour ago and waiting for answers. 2008
I already submited 1 hour ago and waiting for answers … read more
Expert-Repair
Expert-Repair
Owner Kingsland Auto & Marine Services
Vocational, Technical or Trade Scho
11 satisfied customers
When I start my car it is loud like a muffler is gone. when
When I start my car it is loud like a muffler is gone. when I drive it is not loud but when I excellerate the noise is louder … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
I HAVE A 2003 SUNFIRE WITH ONLY 40000 KMS., WHEN I GET UO TO
I HAVE A 2003 SUNFIRE WITH ONLY 40000 KMS., WHEN I GET UO TO HIGH SPEED IT LOSES POWER & SOMETIMES MAKES A KICK, I PUT MY SCANNER ON IT & IT SHOWED MISFIRE PS 300 … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Car off key out and abs light ,oil light ,battery light and
Car off key out and abs light ,oil light ,battery light and air bag light are on ? Also car won't start … read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
5,060 satisfied customers
2000 Pontiac Montana, the passenger side sliding door will
2000 Pontiac Montana, the passenger side sliding door will not open or close. Right now it is partially ajar but will not close nor open. Bought it in the fall, not used to it yet … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
I was rear ended in a car accident and my gas gage is not
I was rear ended in a car accident and my gas gage is not working properly. Could this be from the accident? … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Todd, I have a transmission question about same car. I did
Hi Todd, I have a transmission question about same car.I did the in car overhaul as we briefly spoke about...2-shift solenoids, EPC solenoid, TCC solenoid & pressure plate. I also did a Transgo shift … read more
Todd Audette
Todd Audette
Automotive Technician
Vocational, Technical or Trade School
358 satisfied customers
98 Pontiac grand prix 3.8 ltr battery is new alternatior is
98 Pontiac grand prix 3.8 ltr battery is new alternatior is good, car will run but battery drains down when sitting … read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
My top won't finish closing. 2007 pontiac g6convertible. I
I tried taking out fuses they look fine put them back in and I reset the battery. … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Can't get the door ajar warning to go off tho all doors are
Can't get the door ajar warning to go off tho all doors are secure … read more
Chris (aka - Moose)
Chris (aka - Moose)
Vocational, Technical or Trade Scho
108 satisfied customers
Per our conversation Nov. 2017 I need a wiring diagram for
Per our conversation Nov. 2017 I need a wiring diagram for the 2006 Pontiac grand Prix (supercharged). I asked for a wiring diagram of my relay box so i can locate pin 48. I was told to check wire 48 … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
I'm getting codes P0068, P0106, and P0305. P0068 is throttle
I have changed the MAF sensor. And ignition coil on cylinder 5.… read more
Chris (aka - Moose)
Chris (aka - Moose)
Vocational, Technical or Trade Scho
108 satisfied customers
Starting disabled due to theft system 2006 grand prix. New
starting disabled due to theft system 2006 grand prix … read more
GM Tech (Cam)
GM Tech (Cam)
Pontiac Technician
Vocational, Technical or Trade Scho
2,379 satisfied customers
I have a 2001 pontic grand prix gtp supercharged I bought
I have a 2001 pontic grand prix gtp supercharged I bought the struts assemblied with the spring all together I took off the old strut had no problem but when I but the new strut assembly back the to f… read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
It is Pontiac torrented 2009 integrate traction sign.
Hi it is Pontiac torrented 2009 integrate traction sign … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
5,067 satisfied customers
06 Pontiac G6 delayed forward and reverse. I bought the car
Yes I bought the car it would not move I pulled out the transmission I rebuilt it the direct clutches were burnt replaced all the molded pistons and gaskets and O-rings and sealing rings and this is my problem … read more
Todd Audette
Todd Audette
Automotive Technician
Vocational, Technical or Trade School
358 satisfied customers
It wont start I replaced the ecm still nothing thinking
it wont start I replaced the ecm still nothing thinking maybe the solenoid for starter … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x