I broke the forum ( Honda OEM PS fluid viscosity too light thin for reman rack ?

[AC439]

I posted twice about suspecting the OEM PS fluid too thin for the reman rack and both posting result in "Page not found" error when click on the thread. Sorry guys !

[Oldblueaccord]

No problem. I just locked them.

What fluid would you use?

[Oldblueaccord]

I posted twice about suspecting the OEM PS fluid too thin for the reman rack and both posting result in "Page not found" error when click on the thread. Sorry guys !

it was the back slash in your title it doesn't like. I just did the same thing.

[AC439]

Ah ! Didn't know the back slash is the problem !

Regarding the fluid, I always use Honda OEM. But as soon as the reman is installed and refilled with OEM fluid, I noticed the steering effort is much harder (much less assist). Only I notice when the weather is cold then PS assist back to normal.

My theory is that the seals used in the reman is probably made of a generic material (not Honda) therefore the thinner OEM fluid "slips" pass the seals and giving less assist. Viscosity increases when temp drops and less fluid slipping by and increases the hydraulic pressure differential on the seal therefore giving more assist (sorry, mouth full).

[ShiRen]

Those 2 unread posts are going to bug me lol.

Isn't the fluid type mainly for the pump? The formulation for the OEM fluid has probably changed since then, pumps need less pressure because nobody wants overassisted power steering anymore, plus your pump is also old, it probably struggles more pushing it through the new rack.

[conozo]

I remember someone posting about this a while ago with a reman rack being much harder to steer. They found the solution by some adjustment internally which made it normal again. Something was set to tight when they rebuilt the rack. Sorry that's very vague but i don't think your issue is the wrong type of fluid.

[ShiRen]

Unless there is an adjustment on the valvebody, the adjustment would probably be the the big hex on the bottom to set the rack lash. Idk how tight you can really get that nut before the rack basically locks though, you are supposed to turn it until it bottoms out then back it off a hair. It would not hurt to do that really. I can search the manual here in a bit to see if there is anything else.

[AC439]

I remember someone posting about this a while ago with a reman rack being much harder to steer. They found the solution by some adjustment internally which made it normal again. Something was set to tight when they rebuilt the rack. Sorry that's very vague but i don't think your issue is the wrong type of fluid.

That someone was probably me. I bought the 40mm wrench and back the big nut out a little at a time. It feels a little lighter everytime I backed the nut out until I start to worry the nut may be completely out. It gets to a point that is manageable but still heavy steering (compare to rack replacement).

But with recent cold weather dip, I was expecting heavier steering but it was the opposite. When temp drops, PS assist increases. Therefore, I was thinking about viscosity issue. I also heard Honda changes the viscosity over the years and the fluid becomes lighter.

ShiRen: I also rebuilt the pump just to rule out weak pump. No difference before and after rebuilt so I thought fluid viscosity could be the culpit.

[2oodoor]

Consider the expansion & contraction of the rack components, dissimilar materials, in addition to fluid viscosity.

[AC439]

Consider the expansion & contraction of the rack components, dissimilar materials, in addition to fluid viscosity.

I did consider that. With reman, the rack metals are reused. So I can rule out different metal or dissimilar materials. I think the only thing that has changed during the reman process is the seal material. I doubt the original honda OEM seals were used that makes me think the new seals are probably made of the same material as any other aftermarket seals.

The accidental findings of more steering assistance with lower temp makes me think the Honda OEM fluid is not too compatiable with aftermarket seal material. Same reason for not to use other PS fluids on Honda rack.

If the seals are of different material, the expansion coefficient may very well different than OEM seal material. The very small gaps between seal and metal wall can be out of spec and some of the OEM fluid can slip pass seals until the temp gets cold and viscosity increased to maintain a larger delta-pressure to improve steerng assist. At least, this is my theory.....