[ddvk]

Today we had record temps in CA and while driving back home I realized my steering is stiff. Got home and check the temp of the steering reservior and it is really hot.

Hot fluids do loose steering pressure, curious if that has been experienced in other highlanders (may be I need a cooler if the steering fluid gets really hot).

 

[LifeTech]

I'm really curious about this. I believe the PS fluid has a cooler inline. Do yu have the V6 or 4 banger?The fluid is fairly new if yu have an 06! How hot did yu say the ambient temp was ? And how did yu measure the Fluid temp. I would use a Digital Infrared Thermometer (Radio Shack $39)to check stuff like this. Just point and press button to get an accurate reading. I have solved many a car problem with this. From brakes to radiators even houshold problems with a/c etc.I would check the intake and return lines near the reservoir.Take readings when the PS is working, i.e engine is running. Compare differences. Sounds stupid to ask, but, did yu check tire air pressure on the front wheels?

Does the fluid have bubbles or is it seem foaming up. Then change the fluid. Use the turkey baster technique. I notice that the reservoir says dextron ATF for topping off. But some dealers offer the Toyota PS Fuid. I feel what is factory filled IS a PS specific Fluid. But some just use Dextron ATF fluid. Something to think about. Did the Fluid appear darkish in color (brown?)
My 06 with 5,800Miles , the fluid has darkened a bit. But it should never foam up or Get bubbly . Or foam should dissapate quickly upon cool down. This could be a minor air leak/ loose line or just Bad Fluid. I flushed my 01 Avalon recently and it made a difference. I used Toyota Dextron that I had laying around. Doesn't take much capacity. I emptied/refilled the reservoir twice ,approx a week apart(aprox 150 miles) to fully purge the old fluid out. It looked very clean after the second fill.
Just some thoughts.

LT

 

[ddvk]

I didn't use a thermometer to check the PS fluid temp. But with the ambient around 80F, I think the fluid was close to 100F and that is kind of normal, what is not normal is the power steering getting stiff, starting off normally.

The cooler is in the transmission and not the PS, all that the PS system has a aluminum tubing going to the front of the vehicle near the radiator and turning back to the pump. The notchy feeling does happen in my maxima but then the maxima is nose heavy with low clearance and the PS fluid getting hot is normal.

I am thinking of putting a cooler in the PS path if this continues to get worse, but before that I will have Toyota diagnose the problem. I have heard that Toyota PS systems are underengineered and their cooling system overengineered (the toyo vehicles in general run hotter than other vehicles I have owned).

Tire pressure should be around 38psi in the front and 36psi on the rears...

 

[ddvk]

I am going to go ahead and install a Pemacool cooler.

Yesterday I checked the PS return line coming from the rack to the left front of the vehicle and back to the reserviour. The installation should be simple, since I have a similar ATF cooler on the right side of the vehicle.

All that I need is PS hoses, pressure clamps (dont like the screw type clamps that cut thro the hoses), and the cooler. I will also flush the old PS fluid out and put in syn ATF.!!!

Shall keep you all posted.

 

[LifeTech]

[

Tire pressure should be around 38psi in the front and 36psi on the rears...[/quote]

Yu like your tires very hard?
I don't. The ride,traction, and handling suffer with anything more than 32psi... to me 30PSI feels best though.
But, I am running O/E Limited 17 inchers which have a slightly lower profile than the 16 inchers!

LT

 

[LifeTech]

If yu have the tow prep package, the P/S cooler is included. But an aftrmarket would be just as good if not better. Especially if yu choose to mount it at the right hand side lower intake much like the Tranny cooler on the left side of lower bumper.
Curious...
Which Synthetic ATF would yu choose?
LT

 

[ddvk]

I don't have synthetic PS fluid, it is the boutique fluid from factory that doesn't even smell like PS fluid. If I were to install the cooler, I will flush the factory fill with Amsoil/Mobil1.

BTW, I looked all over there is NO cooler for the PS inspite of me having the tow pkg, all that the towing pkg has is higher capacity radiator and alternator and a ATF cooler and the wiring to the back. There wasn't a hitch too, (damn thing costs $160 couldn't that come std, toyota punks).

 

[LifeTech]

I meant to say what Synth ATF would yu purchase for the refill?

DO yu have the 4-cyl or V6 4wd. I agree the tow pack says it includes a PS cooler in brochure for 06 if I am correct. Yu got me checking mine now.
I have included some info from the maual...

 

[ddvk]

LifeTech:

I looked thro ur attached PDF file, there is no cooler, all that is there is a vane pump with gear and the reserviour.

If you tow without a PS cooler, I must say one is asking for trouble in the hotter states. One may be fine w/o a PS cooler in cold states, definetly not CA.

Hope this helps, I will choose synthetic fluid Amsoil ATF/ Mobil1 ATF if I were to flush the PS.

 

[LifeTech]

Do yu have the cold weather pack option...could be a conflict with the PS cooler addition. I notice when the weather is very cold (below 20F.) Fluid stays thick and gives hard steering. BTW, the manual shows 167F-176F. as the operating temp Range. This could possibly mean the PS cooler is omitted for colder regions. Just a thought.
This has got me wondering. I had thought of using a synthetic equivelent of Dexron II 0r III too, when I observed stiff steering when very cold!!

LT