Hi I'm aware this is a common issue that's posted but I'd really like some insight into my issue & hope it will help others experiencing the issue if they come across the post!

I decided to change my power steering fluid after inspection of how black the fluid is, I did a decent amount of research into what fluid is commonly used, manufacturer ofcourse recommends Dextron iii but I saw a lot of people saying they used fully synth ATF so decided to settle for that as I found dextron more difficult to get hold of locally & read that the properties of the fluid are very close. The problem I found from changing the fluid out is now my power steering is noticeably heavier, there's been a very small whine presumably from the power steering pump since I got the car last month hence why it was a cheap find, although the steering felt great & since changing out the dirty fluid it's become so weighted. Any insight would be appreciated, the only thing I can think is that's there is air in the system as I just sucked from the reservoir 4/5 times running the car 5 min drives at a time instead of a proper flush or the fluid has caused the heaviness. I've gone ahead and ordered dextron iii in the meantime. Any help or wisdom from this great community would be hugely appreciated they don't build cars like this anymore! Cheers. Luke .

 

There's no bleeding required for the power steering system in your car, it will clear itself fairly fast. I had a 96 and it would have aerated fluid for about 5 minutes after a drain n fill/flush then it was good.
Can't really tell you about the synthetic fluid but I always used dexron of some type. Maybe you just didn't notice the noise before you changed the fluid? those non vvti models had an issue with fluid leaks on the bottom of the pump from the lines that could do damage if left for too long before repairing.

 

Thankyou that's really helpful! I'll bleed the system and then refil with Dexron hopefully it will make my steering light again. I'm just confused how this could just happen due to fluid, would that make sense at all? when I bought the car the pump was whining very lightly & I did get money off the car due to this although despite this the car drove great & super light on steering but since changing the fluid it's so heavy! just hope I havn't caused any damage putting ATF in the system

 

Bleeding the PS system:

• Raise the front wheels off the ground and support with jack stands.
• With the engine off, turn the steering wheel slowly from lock to lock several times.
• Lower vehicle onto the ground.
• Start the engine and let engine idle.
• Slowly turn the steering wheel to the right or left, hold at the stop for a few seconds, then turn the other direction and repeat hold for a few seconds. Do this several times.
• Shut engine off and check reservoir for foam/bubbles.
• If foaming/bubbles don't disappear after two bleeding cycles, check system for leaks.

 

Thank you I appreciate that, do you know if the type of fluid or air in the system would cause heavy steering. I turned the wheel left to right several times and saw no bubbles come through

 

EDIT: T-IV is not a replacement for Dexron 2\3. The following is wrong.

Any Toyota\Lexus dealership should still be stocking T-IV fluid. Amazon also sells it by the case, both for about 8 bucks per bottle. I don't think this should be different because you're in the UK.

I would recommend sticking with the correct fluid, especially for the power steer system. "fully synthetic ATF" could mean anything. The system is rather sensitive to having the correct fluid IMO. And it's not like the correct fluid is significantly more expensive either.

I believe the following are all the same fluid (it's all Mobil 3309)

Toyota\Lexus T-IV
Aisin T-IV
Mobil 3309
Idemitsu TLS

 

T-IV will work okay but the viscosity range is not a good match. Use this and never look back.
https://www.amsoil.com/p/amsoil-oe-m...ion-fluid-otf/

 

How does the OE fluid not match in the viscosity range?

 

Dex III- KV at 100 degrees 7.9, BV 17,600, V index 186
3309 - KV at 100 degrees 7.1, BV 13000, V Index 181

As this is a power steering thread we really shouldn't be discussing 3309 (T-IV) and its equivalents it will only confuse future readers.

 

oh




well, ****

Why the hell have I been under the impression that you run T-IV fluid in the power steer for ages. I must have conflated ATF with it somehow. It should be Dextron 2\3 [or similar].

 

I worry that your new ATF washed away sludges /cloggings and those caused the blockage at narrow paths of the liquid and the strainer. As is written here, most ATFs contain detergents, dispersants and surfactants other than others. I'd check the strainer first and see how it is clogged.

 

Is there any power assist or does it just feel "heavy"?

Did it always feel heavy?

Have you checked the tire air pressure?

When was the last time you had the alignment checked?

 

One theory I have is that there was either an air bubble or blockage somewhere in the system and starving the pump or cavitating the pump knocked it loose.
If you have any other questions let me know.

 

This is all really useful, thank's for the posts. Essentially the steering just became heavy straight after the fluid change, not crazy heavy but no where near as light as it was! I used the method where you remove and replace from the fluid housing/ reservoir so not sure if that would cause a blockage or not from the filter! One other thing I've noticed is I'm really not getting any bubbles coming out when turning the wheels like the fluid isn't flowing properly.

I've got dexron 3 on order so will be putting that in when it arrives & also an air bleeder kit, not sure if that's a good move or not you guys could let me know. Would sucking the fluid out from the resovouir cause any hose leaks or anything from the pressure? Also any more suggestions would be great as It's driving me up the wall haha

 

Steering weight can be quite sensitive to changes to the system. I've had even mild alignments (less than half a degree of adjustment to front camber\toe) significantly change the steering weight. I replaced the power steering rack bushings, that had quite a broad impact to the steering quality as well. From bushings to the rack!