Filter In The Steering Rack Solenoid

[rtd111]

91 LS400.

I am interested in getting the filter that is in the solenoid on the steering rack. I can get one only with a remanf rack, which is overkill. If you have a bad solenoid or just the filter -- even if the gauze is ripped or torn, I can take it off your hands... for a reasonable price and shipping costs.

Or any other suggestions how to acquire this part?

[lexus082]

If you can't find the filter that goes in the solenoid, couldnt you just add a in-line filter to the PS System?

[SRK]

The power steering line pressures run average at 1000psi, and will spike higher than that. No filter casing can withstand that much. That's why an integral strainer is used.

[nc211]

srk, are you sure man? i thought bicolini had one in his car? not to be a smartass or anything, but i hope you're wrong on this one, becuase the screen at the bottom of my power steering tank has one big ole' nasty hole in it, making it useless in the sense of filtering out the crud, and was thinking about installing an inline filter on the return line into the tank.

[SRK]

Well a filter in the return line would be OK, no pressure there, but also no protection. But anything other than a good steel case filter I wouldn't use at all.

One of the Volvo tricks (I used to work on them) was to hang a small magnet in the resevoir, and the magnet would collect the metallic bits circulating in the system even better than a filter.

[leeelooo]

the filter in my reservor was totally removed due to damage. I could not find a reservor at reasonable price. So i used inline filter ordered from eBay. Does anyone know a way to build a damaged filter reservor?

ps. to hang a small magnet material into reservor is good idea though - it should be built in oil check stick.

[92Lex]

1000 psi? That's absurd. Imagine me boosting my car at 100psi...with an iron block...cmon now. A 30 gallon air compressor can't even take anything above 300 psi without givin' up on you....and we all know how thick the actual compressor wall is. For a P/S line, I'd say 200 psi max. I could bend that line with my hand.

[LScott400]

1000 psi? That's absurd. For a P/S line, I'd say 200 psi max.

:whistles:

PS_specs.pdf

[SRK]

:whistles:

PS_specs.pdf

Thank you sir. You are a scholar and a gentleman. Nonetheless I was mistaken - the pressures are higher than I had thought.

[Threadcutter]

Thank you sir. You are a scholar and a gentleman. Nonetheless I was mistaken - the pressures are higher than I had thought.

S:

You're a hoot!............. :D

I keep it straight by thinking of one Daniel Bernoulli..........

Bernoulli

Pressure & Flow are inversely proportional............

Doesn't exactly explain a 1995 LS400 P/S closed loop circuit, but he doesn't explain the lift vs drag of a 747 wing very well either.......... ;)

[SRK]

S:

You're a hoot!............. :D

I keep it straight by thinking of one Daniel Bernoulli..........

Bernoulli

Pressure & Flow are inversely proportional............

Doesn't exactly explain a 1995 LS400 P/S closed loop circuit, but he doesn't explain the lift vs drag of a 747 wing very well either.......... ;)

No he doesn't, but for that we can invoke the name of Giovanni Venturi, who most certainly could.

SRK

[92Lex]

If those specs were for the actual P/S line then I'll keep my mouth shut and I apologize...my bad. But....yes there's gonna be a but, are those numbers for the steering rack psi, high pressure hose or P/S pump? It isn't specific, it just shows fluid pressure. There's "pressure" through every single line...so which one does the spec actually refer to? The high pressue hose is secured by a weak 10/12mm bolt....cmon now, 1000psi on a 10/12mm bolt is ludacrous.

I just can't imagine 1000+ psi in an aluminum line or rubber hose. I mean, a steel hose of the same thickness can't even maintain that amount of pressure safely. 1000+ psi in a 30 gallon air compressor wouldn't be a friendly situation. The rubber hoses can only handle 300 psi or so. We all know how thick the walls of an air compressor is and the compressor is still unable to hold that psi.

I hope y'all don't think that I'm coming off as a dickkk. I'm not trying offend anyone. I just don't want confusion. 1000+psi is no joke.

[LScott400]

Thank you sir.

My pleasure :)

I just can't imagine 1000+ psi in an aluminum line or rubber hose.

Power Steering Hose

[92Lex]

http://www.woodwardsteering.com/powers3.htm

[Threadcutter]

If those specs were for the actual P/S line then I'll keep my mouth shut and I apologize...my bad. But....yes there's gonna be a but, are those numbers for the steering rack psi, high pressure hose or P/S pump? It isn't specific, it just shows fluid pressure. There's "pressure" through every single line...so which one does the spec actually refer to? The high pressue hose is secured by a weak 10/12mm bolt....cmon now, 1000psi on a 10/12mm bolt is ludacrous.

I just can't imagine 1000+ psi in an aluminum line or rubber hose. I mean, a steel hose of the same thickness can't even maintain that amount of pressure safely. 1000+ psi in a 30 gallon air compressor wouldn't be a friendly situation. The rubber hoses can only handle 300 psi or so. We all know how thick the walls of an air compressor is and the compressor is still unable to hold that psi.

I hope y'all don't think that I'm coming off as a dickkk. I'm not trying offend anyone. I just don't want confusion. 1000+psi is no joke.

Lex:

SRK is correct.........Yes, the Spec sheet does say 1280 PSI Fluid pressure at idle speed with valve closed.

I'm by no means an expert in hydraulics, compressed air (or anything else for that matter), but the simplest way to look at the P/S system is that of a hydraulic pump (the P/S pump) and a hydraulic positioner/servo valve (the steering rack). The high pressure output side (discharge) of the P/S pump is indeed high pressure (as high as 1280 PSI) when under mechanical load. The important thing to remember (and my point in my earlier post) is that pressure and flow are inversely porportional. This means that when the output pressure of the P/S pump is high, the flow is low, and vis versa.

If you think a little bit about it, what is the pressure and flow of the Hydraulic (P/S) fluid on the downstream side of the Steering rack? Yes, the flow is high, so, the pressure must be low. Just (carefully) remove the P/S reservior cap with the engine running sometime. You will see with your own eyes that flow is high & it will be very obvious that pressure is low (relatively speaking).

To my knowledge, there are no (ordinary) rubber hoses on the discharge (output side) of the P/S pump, for reasons that you correctly point out in your post(s) above. That is, the pressure on the discharge side of the P/S pump can be as high as 1280 PSI (remember, at low flow), so high pressure hose is in order. This can be in the form of Stainless tubing and/or braided high pressure hose that will withstand not only the high pressure, but the high levels of heat as well. When I refer to heat, I'm speaking of the heat that is created as a byproduct of attempting to "compress" the hydraulic (P/S) fluid, which by it's very nature (being a fluid) does not want to compress.

Now, once the hydraulic fluid has done "work" at the steering rack, a great deal of pressure is "lost", meaning the pressure is reduced dramatically between the discharge of the P/S pump and the steering rack. So, as a result, the pressure of the fluid between the "downstream side" of the steering rack and the P/S pump reservior is low (so, the flow is high). That's why you WILL find regular "ol' rubber hose coming back into the P/S reservior from the downstream side of the rack......the pressure is very low (again, relatively speaking).

I'd suggest letting loose of any comparisons to compressed air. We're talking hydraulics here. Apples & Oranges. One of the big differences with compressed air (regardless of pressure) is that, well, it will compress......Whereas, a fluid (like P/S fluid, or water) does not want to compress. Ever blown a headgasket & had anti-freeze/water in a cylinder? The engine doesn't want to turn over very well, does it? That's because the antifreeze/water doesn't want to compress like air does.

(Oh, & by the way........watch out for S........ Triple check your facts before challenging him. That cantankerous old goat will get you EVERY time!......Trust me, Been There, Done That.......)

[SRK]

(Oh, & by the way........watch out for S........ Triple check your facts before challenging him. That cantankerous old goat will get you EVERY time!......Trust me, Been There, Done That.......)

Threadcutter you are obviously a fine judge of character, and probably whiskey and women too.....

I noticed in the Woodward Steering pdf on technical data that one is advised to use hose rated for 1500 psi minimum.

Lex the capabilities of modern neoprene re-inforced hose should not be underestimated. Every time you step on the brake pedal you are trusting the flexible lines at each wheel to 500-1000 psi on a moderate stop, and in panic mode nearly 2000 psi. And you can tie a knot in those hoses quite easily.

A pal of mine is a SCUBA diver ( I don't partake in such activities, being, as pointed out previously, old.......) and he tells me the hose to the regulator is rated for 4500 psi. The tanks contain up to 3000 psi on a normal fill.

You're right though, 1000 psi and pressures greater are no joke, and are downright dangerous.

Time for my next feeding - there are a couple of empty tin cans with my name on 'em.....and lord knows I get grumpy when hungry....

[92Lex]

Yea, I know....this is going to be one hell of a debate.

If you read carefully, flow shouldn't be mistaken for actual PSI. That PSI spec you read is for resistance within the pump and rack cylinders....not base system pressure (about 150psi). There are "check valves"....but that's beside the point. PSI would be a stuck valve or counter reaction of the rack cylinders (resistance).

Honestly, you had my mouth shut for a minute....but I searched around and found that astonishing article. 1000+ psi is possible, but 1000+ psi flow is something else. Pressure is caused when there is no other possible method of "flow"...thus resulting in resistance (PSI). You're saying that your P/S line is constantly "pressurized", at 1300+ psi? Possible. But wouldn't a 1300+ psi "flow rate" seem more rational? Just means that the fluid should hypothetically flow at the rate of what an open ended 1300+ PSI system would produce...when one side of the sealed system was abruptly "cut" open....even though at no point that hose had 1300+ psi internally present.

Threadcounter, even if those specs were based off of the check valve closed....does it state on which side of the check valve those numbers were taken off of? 1000+ psi in a P/S pump....that's probable. 1000+psi in a rubber hose no, but 1000+psi fluid flow I can accept.

SRK, the tank system on the scuba gear may be capable of 4500psi, 3000 psi tank and 1500 psi hose...right? 3000psi tank I can believe, I mean those things are heavy as hell. 1500 psi Within the hose? Not to cause an arguement or anything but I honestly don't think that it's possible. To be reasonable....I'd say 3000psi in the tank and 1500psi Flow within the lines. 1500psi would blow your lungs out...not a good feeling huh? That's where the check valve would come into play.

If I'm wrong then I'm wrong. But I'm going put up a fight until then. I'm not going for a win or loss. We obviously have different opinions. I'm not saying that you're right or neither am I. I'm just here to understand the things that neither you nor I am aware of.

BTW, I love whiskey on the rocks.