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Alternator needs repair - what else should I do while "I'm in there"?

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Old Mar 11, 2026 | 09:48 AM
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Default Alternator needs repair - what else should I do while "I'm in there"?

The alternator in my 2011 needs its voltage regulator replaced so I'm going to take it out and bring it to a shop to get it refurbished.

Question: Is there anything else I should do while I'm working in that area?

I will replace the serpentine belt since it's still the original.

Anything else?

Some coolant needs to be drained out to prevent spillage because the top radiator hose needs to be removed. Should I replace ALL the coolant? I've heard some people say that coolant doesn't need replacing these days but it is 15 years old now.

Water pump?
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Old Mar 11, 2026 | 04:38 PM
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How many miles are on it?
Check the idler pulleys and belt tensioner. They sell replacement kits with all the parts.
Leave the water pump alone if it is not causing any issues, is quiet and not leaking.

Do a drain of the coolant via the radiator and replace that coolant. Only use Toyota Super Long Life. It is premixed.
See this video from the Car Care Nut a Toyota Master Tech on how to change and bleed the coolant on this engine.

​​​​​​

Last edited by Clutchless; Mar 11, 2026 at 04:39 PM.
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Old Mar 11, 2026 | 07:11 PM
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Originally Posted by Lexterious
The alternator in my 2011 needs its voltage regulator replaced so I'm going to take it out and bring it to a shop to get it refurbished.

Question: Is there anything else I should do while I'm working in that area?

I will replace the serpentine belt since it's still the original.

Anything else?

Some coolant needs to be drained out to prevent spillage because the top radiator hose needs to be removed. Should I replace ALL the coolant? I've heard some people say that coolant doesn't need replacing these days but it is 15 years old now.

Water pump?
If you can remove the alternator, servicing it is very easy. I would replace the brushes and the rectifier's. Test out the bearings, but they usually do not go bad.

Salim
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Old Mar 11, 2026 | 10:19 PM
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Originally Posted by Clutchless
How many miles are on it?
Check the idler pulleys and belt tensioner. They sell replacement kits with all the parts.
Leave the water pump alone if it is not causing any issues, is quiet and not leaking.

Do a drain of the coolant via the radiator and replace that coolant. Only use Toyota Super Long Life. It is premixed.
See this video from the Car Care Nut a Toyota Master Tech on how to change and bleed the coolant on this engine.

​​​​​​https://www.youtube.com/watch?v=UJe1dbFVoqw
How many miles? Only 60,000 miles (100,000 Km). It's not driven too much.

Does the coolant still need changing with this low miles? With cars of old, it might have been due, but I understand that coolant is better or longer lasting these days.
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Old Mar 11, 2026 | 10:24 PM
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Originally Posted by salimshah
If you can remove the alternator, servicing it is very easy. I would replace the brushes and the rectifier's. Test out the bearings, but they usually do not go bad.

Salim
Yes, I mis-spoke. I was going to take it into a local shop to refurbish it with a new regulator and then have them checkout and replace anything that needs replacing such as the brushes and perhaps the bearings.

The sad thing is that with labour, the fee for the job will be close to what I can get a reman Denso for online. But by having it refurbished, I know that I'm getting my OWN fairly low-miles (60,000) alternator back instead of an alternator of "who knows how many miles" and perhaps not competently refurbished (at least that's my thought on the matter).
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Old Mar 12, 2026 | 01:09 AM
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Originally Posted by Lexterious
How many miles? Only 60,000 miles (100,000 Km). It's not driven too much. Does the coolant still need changing with this low miles? With cars of old, it might have been due, but I understand that coolant is better or longer lasting these days.
Coolant test strips are available at parts stores which show if coolant has become acidic. It's easy to locate the drain plug at bottom of Toyota radiators, open radiator cap, drain whatever coolant comes out, then replace and fill system with premixed Toyota Super Long Life coolant.
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Old Mar 12, 2026 | 06:04 AM
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Toyota calls for the Super Long Life coolant to be replaced after 10 years. Your vehicle is 15 years old as is the coolant. You need to take this opportunity to change the coolant.
However, since you now explained that you are taking it to a shop it is out of your hands because they will likely just drain and replace your old coolant.
They are not going to save and reuse old coolant of unknown age.

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Old Mar 12, 2026 | 08:07 AM
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Originally Posted by Clutchless
Toyota calls for the Super Long Life coolant to be replaced after 10 years. Your vehicle is 15 years old as is the coolant. You need to take this opportunity to change the coolant.
However, since you now explained that you are taking it to a shop it is out of your hands because they will likely just drain and replace your old coolant.
They are not going to save and reuse old coolant of unknown age.
No, I'm cheap. And thus I'm taking just the ALTERNATOR to a shop. I'm removing it myself and will reinstall it after I get it refurbished.

And while I'm out and about, I will take your advice and pickup some fresh Toyota coolant and change out the amount that drains out. Cheers.
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Old Mar 12, 2026 | 08:18 AM
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Originally Posted by Lexterious
Yes, I mis-spoke. I was going to take it into a local shop to refurbish it with a new regulator and then have them checkout and replace anything that needs replacing such as the brushes and perhaps the bearings.

The sad thing is that with labour, the fee for the job will be close to what I can get a reman Denso for online. But by having it refurbished, I know that I'm getting my OWN fairly low-miles (60,000) alternator back instead of an alternator of "who knows how many miles" and perhaps not competently refurbished (at least that's my thought on the matter).
I did the very same thing with about 200K miles on my 1st gen. I got the rectifier, brushes and controller from Lexus parts. Only tool I needed was phillips screw driver and sandpaper. 5" vice made it convenient but is not a must. Labor was mine [ihr]. Reman way is cheaper as the parts they use are very likely not OEM. I did go to the box store to test the alternator before and after refurbish/repair.

Salim
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Old Mar 12, 2026 | 11:57 AM
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Originally Posted by salimshah
I did the very same thing with about 200K miles on my 1st gen. I got the rectifier, brushes and controller from Lexus parts. Only tool I needed was phillips screw driver and sandpaper. 5" vice made it convenient but is not a must. Labor was mine [ihr]. Reman way is cheaper as the parts they use are very likely not OEM. I did go to the box store to test the alternator before and after refurbish/repair.

Salim
Thanks. It sounds tempting to repair the alternator myself but I think I'll just get the shop to do refurbish it. We don't have places like Autozone where they will test your alternator for you. And I don't want to screw up the fix such that I will have to fuss with taking the alternator out again.

I long for the old days when you could swap out an alternator with a crescent wrench and a crowbar. Now with the transverse V6, so many bits and pieces (e.g. the grill) has to come off first that I want to do it just one time if possible.
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Old Mar 12, 2026 | 08:15 PM
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Originally Posted by Lexterious
Thanks. It sounds tempting to repair the alternator myself but I think I'll just get the shop to do refurbish it. We don't have places like Autozone where they will test your alternator for you. And I don't want to screw up the fix such that I will have to fuss with taking the alternator out again.

I long for the old days when you could swap out an alternator with a crescent wrench and a crowbar. Now with the transverse V6, so many bits and pieces (e.g. the grill) has to come off first that I want to do it just one time if possible.
Ok ... you might get into a situation where the repair shop might insist on purchasing parts [contractual and or financial agreements] and they might not be OEM. Some repair facility might accept your purchased parts but then they do not offer warranty. Personally I would insist they bench test the alternator before handing it back to you. That begs the question that can they test the alternator that you refurbished for a nominal fee?

Oh, what test was performed to determine that the alternator is bad to begin with?

Salim
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Old Mar 13, 2026 | 05:43 AM
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Originally Posted by salimshah
Ok ... you might get into a situation where the repair shop might insist on purchasing parts [contractual and or financial agreements] and they might not be OEM. Some repair facility might accept your purchased parts but then they do not offer warranty. Personally I would insist they bench test the alternator before handing it back to you. That begs the question that can they test the alternator that you refurbished for a nominal fee?

Oh, what test was performed to determine that the alternator is bad to begin with?

Salim
Thanks. I've used the company before a long time ago. They refurbished an alternator for me on a different brand of car.

Last time, they checked and determined the alternator was bad before fixing it, but I will doublecheck. I will also ask what type of regulator they use.

That's an interesting question regarding asking them for the charge to test an alternator that I repaired myself.

The company is in the business of refurbishing starter motors and alternators and thus, despite the high-ish cost, I'm leaning towards using them because of the hassle of removing it and I wanting to do it only once. The RX is another family member's car and so there's that additional hassle.
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Old Mar 13, 2026 | 06:33 AM
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I also have my alternators refurbished by a local starter & alternator shop that has been in business for decades. For Denso alternators, they always use the proper Denso parts kit. As a result, I have never had a problem with them.
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Old Mar 13, 2026 | 07:17 AM
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Originally Posted by Lexterious
... while I'm out and about, I will take your advice and pickup some fresh Toyota coolant and change out the amount that drains out. Cheers.
This video is worth watching for coolant change, I did 2 drain and refills and pulled out coolant in overflow each time which gives about 75% new SLL coolant in the system;
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Old Mar 13, 2026 | 08:14 AM
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Originally Posted by RX in NC
I also have my alternators refurbished by a local starter & alternator shop that has been in business for decades. For Denso alternators, they always use the proper Denso parts kit. As a result, I have never had a problem with them.
Agreed! if you trust a shop, they deserve return business.

Salim
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