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Daves71, ASE Certified Technician
Category: Chevy
Satisfied Customers: 719
Experience:  35+years experience in automotive repair
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how to install a bypass pulley to replace blown out air compressor

Customer Question

how to install a bypass pulley to replace blown out air compressor and what to do with the a/c lines, when installing a bypass pulley? this is on a 99 S10 Chevy Blazer.
Submitted: 6 years ago.
Category: Chevy
Expert:  Vladgmru replied 6 years ago.
Thanks for using JustAnswer.
My name is Vladimir.
If your A/C compressor is seized and you do not need your A/C system working, you do not have to replace the A/C compressor or installing a bypass pulley.
If the A/C compressor pulley is OK and turns over freely, you just need to disconnect the A/C compressor clutch electrical connector so it wouldn't engage.
In case the A/C compressor pulley is faulty, you just need to replace its bearing ( do not connect the clutch connector after that).
Let me know if you need more assistance.
Customer: replied 6 years ago.

So I took your advice and did what you said. the truck is running but is really noisey, is it suppose to be this way?

the clutch plate had burned up, but the pulley on the a/c unit is still freely turning, but it is noisey when running, like I said. How do I know if this is the bearing? And if it is the bearing then how do I replace it?

My husband is concerned his truck is going to freeze up, or whatever and insists on my installing the bypass pulley! Is there any way I can reassure him his truck is fine??

And if push comes to shove and I have to install the bypass pulley can you give me instructions and a diagram of how to do so?

I apologize for taking so long to get back to you, but have been sick.

Expert:  Vladgmru replied 6 years ago.
Welcome back!
Hope you are feeling better.
Unfortunately a can't hear a noise, so it is almost impossible to say if it is the A/C pulley or alternator, water pump etc.
You should remove the serpentine belt and turn by hand every pulley. listen if it makes a noise and replace a suspected part.
I doubt you will be able to replace the A/C pulley bearing because it requires using a hydraulic press and some mandrel. Is it is the A/C pulley failure, you'd better have it replaced in a shop.
I haven't heard that it is possible to install a bypass pulley on this engine and I do not think it would be cheaper that fixing original problem.
Customer: replied 6 years ago.
Hmmm... I am going to go with my hunch here that my main focus is still around the a/c unit pulley. That seems odd you would suggest I replace the bearing, then tell me I can not do it without certain equipment! As odd as it may sound to you there are companies that do sell bypass pulley for 99 chevy s10 blazer! I have one here at my house, so I do not find it impossible to install it, just needed guidence but I am a quick learner,and can figure it out!
Expert:  Vladgmru replied 6 years ago.
Well, I told you about the bearing replacement as an alternative choice to a bypass pulley installing.
I do not know about your repair abilities , so i can just guess if you can or can not.
I have tried my best in order to help you.
I feel that you are unsatisfied with my answers and I see you have four questions and no one has been accepted by you. That also seems odd .
I am going to opt out and open your question for other experts that may be have a better advice.
Sorry for any inconvenience and have a good day!

Edited by Vladgmru on 11/2/2009 at 10:46 PM EST
Expert:  Daves71 replied 6 years ago.

Hi,which engine do you have(4 cylinder or V-6).This is not hard to do ,remove the compressor refrigerant lines(it would be good to remove and recycle the refrigerant if possible)and be careful not to inhale escaping gases.Then remove the compressor and install the by pass pulley kit.Remove the refrigerant lines as far back to the firewall as you can and block them off as well as you can(if you decide to repair the A/C later it will keep water out of the system).Then install the serpentine belt in its original routing. If you need more help please let me know,thanks,





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