Power steering cooler plumbing questions.

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The Artist formerly known as Turbo84
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I'm planning on finally putting a cooler in the system over the winter. I'm not a big fan of the normal cooler placement (downstream of the rack), as it just seems like the fluid gets all heated up in the pump while driving down the straights, and then the hot fluid gets sent straight to the rack, and after heating up the rack it gets sent through the cooler. This all seems incredibly inefficient (regarding trying to keep the rack cool).

I'm curious. What would be the downside(s) to putting a Tee fitting in the pump outlet, with one line going straight to the rack, and the other line (with a small pressure-dropping orifice at the Tee fitting outlet) running to the p/s cooler in front of the radiator? This would keep the normal path for fluid to the rack, for normal steering operation, but the extra loop would allow a continuous flow of the hot fluid through the cooler, allowing heat to continually be removed. (There would obviously be two return lines going back to the pump reservoir.

One downside is that there are now twice as many lines to possibly leak. Another is that there would possibly be some loss of steering boost/assist, depending on how much fluid is shunted to the cooler line. Are there others I'm not recognizing at the moment?

Thanks for any constructive input.
 
Dump the PS and get a Steering Quickener?
Just thinking...
No pump, No Belt, No cooler.
thum_12695bdac83ed2341.jpg

Cheers - Jim

Well, the steering is already quite quick. It's the low speed effort I don't care for. I believe a quickener would just increase the effort.

Another idea I'm curious about, but don't know if it's possible, would be to tap into the pressure regulator/relief portion of the pump, and when the relief valve is opening (as in straightline times) than the relief volume would go to the cooler, but during cornering when there is actual flow out of the pump, the relief flow to the cooler would reduce/stop temporarily.
 
I'm not sure if this falls outside of your OEM appearance preference, but what about an electric hydraulic pump?
ill be running a Mercedes A-Class pump in my car... standalone unit, so simple power and ground hookups, pressure on demand means it won't be generating heat and drag when I'm at 6kRPM going straight. Smaller cooler, less weight, less fluid, and full pressure at idle for parking lots, etc...
seems to be a popular pump for the Porsche GT club cars that run sticky tires and aero.
 
I'm not sure if this falls outside of your OEM appearance preference, but what about an electric hydraulic pump?
ill be running a Mercedes A-Class pump in my car... standalone unit, so simple power and ground hookups, pressure on demand means it won't be generating heat and drag when I'm at 6kRPM going straight. Smaller cooler, less weight, less fluid, and full pressure at idle for parking lots, etc...
seems to be a popular pump for the Porsche GT club cars that run sticky tires and aero.

I'm open to alternatives. I'll confess I'm not up to speed on the details of an electric pump. Off the top of my head: What's the weight of the pump? What's the current draw (Is a bigger heavier alternator needed to provide enough current when the car is in a consistently twisty part of the track?)

My goal is almost always lighter weight, rather than any net horsepower gain. I can keep up with most cars on the straights (and usually braking too), but I'm (self) limited to 11.75" rotors and 8" wide tires (I'm running 15" wheels). I've got 10-20% less vehicle weight than most guys out on the track, but I'm often running with 30% less tire width, hence my "obsession" with weight reduction.
 
The fuse in the Benz is 80A... I would think that speeds above 40mph the pump would be barely running (other benefit is you could turn it off completely at >xMPH) I could see an auto-x giving the pump and alternator a workout, but from what Ive read it seems like these are pretty robust pumps, mechanically speaking. Being that theres an electric motor driving this pump, I wouldnt be surprised if it was over 10lbs...

asse-Power-Steering-Pump-Hydraulikpumpe-4144660101.jpg
 
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8.4lbs is the dry weight according to the guys over at the porsche forums... I just put an offer in on one on ebay.uk...
 
I'm gonna try to transplant the junkyard (aluminum body) Type II pump I got the other day. It looks very similar to the steel/iron pump I'm presently running, but the reservoir shape is competing with the left UCA for space. I'm hoping I can just swap out the reservoir to the one I currently have on the car, in addition to installing my present V-belt pulley onto this pump.

I have one additional issue to address yet, that is the pump outlet pressure. When I pulled this pump off the vehicle (a 2002 Jeep) I forgot to look to see what type of steering (box or rack) it had. When I went back today to check, the vehicle was gone (crushed, I suspect). I looked at several Jeeps in the rest of the lot, and while the Jeep Liberty model has a R&P steering, every bigger Jeep seemed to have the older style box with the pitman arm. I'm under the impression that the older style boxes ran on a higher pressure than R&P systems. Am I correct in this understanding? If so, I was going to see if I can also transplant the internal pressure relief spring (again, if I understand this system correctly) from the old pump.

I've also got a C5Z ps fluid cooler ready to install. I'm still figuring out if I can run a constant fluid cooling loop instead of the intermittent stock loop.

I appreciate any input or corrections here with this endeavor.
 
Measuring the pump output pressure.

I'm tossing around ideas to figure out how much difficulty it would be to connect/adapt the factory p/s high pressure hose to one of my pressure gauges (2000 psi IIRC). I've got an old 120v electric motor sitting on the shelf that I can use to spin my current pump and the recent junkyard pump I got. Getting adapters to join things looks to be a PITA, so I'm currently leaning toward brazing or silver soldering some fittings together (subject to change if further info tells me it won't work).

Better ideas are very welcomed.
 
Well, learned a few things along the way. Apparently the steering rack has a bypass feature to allow the fluid to circulate when assist isn't needed. This certainly simplified things plumbing-wise. I got the C5 fluid cooler installed ahead of the radiator, swapped the previous reservoir and pulley onto the aluminum pump, and ran the lines. That was kind of a PITA having to keep working under the car and then under the hood to get the lines bent in the right directions. Adding the cooler and additional lines and fluid pretty much negated the weight reduction due to the aluminum pump, but life ought to be a bit easier on the rack now that the fluid temps will be a bit more moderate.

I'd still like to take a few more ounces off the pump with a lighter pulley, though. The serpentine pulley that came on the aluminum pump was a plastic/nylon looking piece, weighing 8 ounces. The steel vee pulley I installed on the "new" pump is 15 ounces. Just annoys me that there's almost a 2:1 weight ratio between those two pulleys. I've looked the nylon pulley over pretty closely, but I don't believe there's enough material depth in the belt surface area to have a deeper vee cut into there for use with a vee belt.
 
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