Dave B

Lately I've grown really tired of super boosted 4th gen steering. So I did a little experiment. I popped open the power steering fluid reservoir and I removed enough fluid so that it's a fraction under the "cold min" mark. Overall, I removed about a 1/4" of fluid from the reservoir. Much to my surprise, my on-center steering is much improved and my steering is about 10% heavier. This isn't a mental thing, it really does work.

Caution: I don't know the reliability of this mod since you are running slightly less fluid that what's recommended by Nissan. I can only assume that Nissan builds in a slight safeguard and that running slightly less fluid should be okay on the power steering.


Dave

Eric L.

I really want to do what you did, but am afraid to ruin the power steering system. I mean, it will strain the pump each time you turn the wheel since the pump will try to build up hydraulic pressure, but never does so fully due to low fluid.

I hate the "turn with one finger" softness of the Maxima's steering wheel turn. Even my mom's 99 Camry has heavier steering, and Camrys are supposed to have horrible steering feel!

mzmtg

iTrader: (11)

Perhaps putting some sort of orifice into the supply line going from the pump to the steering rack would work. That way the pump could keep up the pressure and flow rate that it needs, but the orifice would drop the pressure before it got down to the rack...Food for thought.

brubenstein

Since the steering got heavier, that means there is now air mixed in with the PS fluid. I assume that the fluid also lubricates the components it flows through, and the air might cause a lubrication problem. Once it gets warm out you also run the risk of having the fluid getting too hot (due to low volume) and this can cause all sorts of damage.
I also think the steering is way too light. A better mod might be to see if a bigger pully is available for the PS pump, or even a smaller pump, from another model. I think running at a low fluid level will result in premature failure of some parts in the system.

The_quorum

would increasing the viscosity of the fluid affect it at all? Oh, and as a secont thought...I heard PS and Tranny fluid are pretty much the same, is this right?

Keven97SE

Dave, I agree with Brubenstein. Air in the system is bad. You could possibly ruin the pump or other components. Not only does the PS fluid help lubricate and cool components, but air bubbles can trash the metal surfaces like pump impellers, etc and cause some serious damage.

I've taken a looksy at the pump schematics in the service manual, and it looks like the power steering pressure is regulated by a spring-loaded regulator "plug". If I understand the drawing correctly, it looks like if one swapped the spring with either a softer or stiffer spring (can't remember exactly offhand). The regulator is located at the pump outlet. Remove the plumbing there to access the regulator. Reduce the power steering pressure and you reduce steering assist, hence heavier steering.

Again, I'm too lazy to look into my idea. Anybody want to play? A shop specializing in power steering pump rebuilds could probably offer advice as well.

Keven97SE

You'd have to really increase the viscosity a ton to have a significant impact. You're relying on decreased fluid motion to reduce pressure, not an effective way. You'd also decrease the ability to cool and lubricate the PS components, not a good thing. Good idea to decrease pressure, but not a wise thing to do.

humaras

I just wanted to ask you guys that all of you have the "light" steering feeling?
That is normal is my question.

I hope I am not the only one with the "super power assisted" steering.

Dave B

I understand where all you guys are coming from, but it appeared my reservoir was already about 2mm over the "cold max". All I did was take out enough fluid to take it about 1mm below "cold min". I hardly took out any fluid, but what fluid I did take out made just enough difference that I can live with the steering. Hell, maybe my steering felt horrible because it was overfilled at the factory. I've always thought running slightly less than recommended is better than running slightly more than what recommended because too much fluid causes too much pressure to build up.
Last night I drove rather aggressively at slow speeds with lots of turning for about 15 minutes in a attempt to warm up the fluid and test for excessive heat. I felt the power steering lines and they all felt slightly warm and the fluid level was about 2mm above "cold min". Like I said, I think Nissan was make it so that the "cold min" actually isn't the "bare minimum". I don't think running 1mm below the bare minimum will hurt anything (but I've been wrong before). Now I have a 1 1/4" air space between the fluid level and cap or if you look at volume of air, I've got 15.7 cu. inches (my setting) vs 12.6 cu." (cold max) vs. 15.1 cu." (cold min). So technically I've got about .6 cu." more air than what Nissan recommends.


Dave


Dave

Jeff92se

iTrader: (82)

Low fluid = bad

More viscous fluid = hard on the pump

Replacing spring = interesting.

How about using a smaller pulley? You might have to dig around and try to find another Nissan one that's smaller. That's probably your best chance at finding one that's bolt up. Either that or try have one made which = $$.

brubenstein

For a given linear belt speed, the smaller the driven pulley (on the PS pump) the greater the RPM's. Now, a smaller drive pulley (underdrive pulley) will slow down everything driven.

sx7r

iTrader: (15)

why don't you just put some more slack in the belt that drives the power steering pump... the belt is supposed to have around 7 or 8mm of deflection. just give it more deflection and it'll slip giving you "heavier" steering. you can lower the pulley to loosen the belt via an adjusting bolt. there's a lock nut you have to loosen before you can lower it though(12mm).

[Edited by sx7r on 02-07-2001 at 06:17 PM]

BrokenMotor

i have 10 power steering pump FS, free shipping, you guys need some.

sinewave

A larger pulley won't do any good, the pump relief valve will just release at a slightly higher rpm. I sure wouldn't be caught dead driving around with a slipping fan belt. A squealing belt will have everyone staring at my car as if were some POS 1978 station wagon.

Keven97SE is right, the only reliable way to regulate the pressure is with a different spring.

sx7r

iTrader: (15)

fan belt? who said anything about a fan belt? power steering belt is by itself.
get yourself a can of squeak-no-more or squeal-b-gone. if you have the right amount of deflection, it'll slip just enough for you to feel the heavier steering, but not enough to squeal.

sinewave

Sure, just spray a little WD-40 on it. Of course you could use motor oil, then we could debate whether it sould be synthetic so as to get just the right amount of slippage to drop the output pressure of the pump from 80psig to 65psig.

wdave

Increasing the caster will make a big difference in effort too, and also improve general handling.

Dave