Noisy Power Steering

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vt92

vt92

10 Year 15 Year 20 Year
Joined
Mar 17, 2004
Threads
58
Messages
191
Location
upstate SC
22RE, 1990 Pickup

Brief history:

1.) Noisy power steering pump. Bleeding the system did not help.

2.) Interestingly, if I drained the fluid, replaced the fluid and bled it, the noise would go away for a while.

2.) I replaced the pump with a rebuilt unit a couple of months ago, filled reservoir with the fluid and bled the system. No noise for a while, but now the noise is back.

I did the 'screwdriver' test. The noise is not coming from the p/s pump front bearing or the pully bearing. If I try to bleed the system, I get no bubbles.

Any ideas on what is causing the noise? It is most noticeable at slow idle. The load doesn't affect the noise, like is typical with faulty pumps.

Thanks for your help.
 
Mine used to howl like a banshee when I would start the engine on really cold days. Last year I rebuilt a spare pump with OEM parts (seals, bearing, etc), and swapped it on. Complete flush and fill with Amsoil synthetic ATF, and it has been fine since. Totally quiet this morning when I fired up at 4 deg outside.
 
I have seen very good results from changing Toyota systems to light hydraulic oil, the brand that I use is Mobil DTE Light ISO 32. If your getting the classic power steering groan, the system has new fluid and bled well, it's most likely from cavitation. Cavitation is bubbles that form and collapse at the point extreme pressure change, most of the time from contaminants in the fluid.

ATF is hydraulic oil with additives like, clutch friction modifiers, detergents, coloring agents, etc, that are unnecessary in a pure hydraulic system like power steering and would be considered contaminants in that type of system. A Toyota tip is add a cap of Downy fabric softener if the ATF makes it whine, great more additives, I have had better results from just changing to a pure hydraulic oil.
 
vt92 said:
Tools R Us - Thanks for the tip!!!! I replaced the ATF with regular ISO32 Hydraulic fluid and the noise is gone!
Click to expand...

Good news!:cheers: I have had very good results running it in many Toyotas.
 
Bear80 said:
Eh, I tink you should read your owners manual, older pumps do not use ATF.
Click to expand...

I have seen several different recommendations from Toyota over the years, this is from the '85 FSM;
1985toyotatruckfsm0732.webp
 
That's exactly what it says on the sticker on my reservoir. I've never seen one that DIDN'T specify ATF, do you know what years use something different? I'm curious.
 
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