demonspeed

iTrader: (7)

I figured I'd take a couple of pictures to ease the minds of anyone concerned about ripping their frame-mounted cooler off. Keep in mind I'm lowered about an inch (SLP's). Hope this helps!

cdgreg

iTrader: (5)

Stupid question: does the PS and radiator flush come AFTER the aftermarket cooler install? Or something like drain all>install>flush?

RPM WS6

iTrader: (3)

As promised, I took some follow up readings in the warmer weather.

Similar driving situation as before, 17+ miles in city conditions with turns, plenty of traffic, and also some open stretches of road. Here were the conditions/results:

Car: '02 Z28 with aftermarket 17x9.5" wheels, 275/40 front tires, stock t-stat, stock fan settings. No PS cooler of any kind.

Temps:
- Outside air temp: 77°F
- Road surface temp (per IR gun): 105-110°F on average
- Power steering fluid temp (in reservoir, per fluid thermometer): 180°F
- Power steering cooler surface temp (per IR gun, still located in radiator hose but disconnected from the PS system): 194°F

Conclusions:

- It seems that the fluid temp and outside air temp increase at slightly less than a 1:1 ratio (air temp 77°-54°=23°, vs. fluid temp 180°-162°=18°).

- The stock PS cooler surface temp was a bit hotter than the fluid in the reservoir (granted, two different types of thermometers were used).

- I'd like to try this again when the outside temps are more like 85-90° and see what the fluid temp is. So far, I'm not seeing enough heat to be concerned. Based on the surface temps of the factory cooler, it seems that the PS fluid would have been no better off had it still be routed through the cooler - at least under my driving conditions.

- I'm not convinced that the factory PS cooler is good for any sort of actual cooling under normal driving conditions in temps less than ~80°F (so far). I can only assume that under severe conditions or much hotter outside temps that it might serve a purpose.

- If you actually want to cool the fluid, forget the factory cooler and go aftermarket air-to-fluid (unless of course you have a modified cooling system that keeps coolant temps lower than stock).

demonspeed

iTrader: (7)

Very nice to see some empirical evidence.

I've started to notice some seeping from the cap hole on mine. I'm not sure if it's due to heat or due to overfilling the reservoir. I'll keep an eye on it, but I may have a cooler available to anyone who wants to give it a try

wssix99

iTrader: (5)

Was the engine still running when you took this temperature? I wouldn't have expected it would be this high.

RPM WS6

iTrader: (3)

Yes, the 194° was right when I pulled into my driveway and popped the hood. I didn't have my scanner hooked up, but the low speed fans were running at that time which means that engine coolant temps were somewhere in the 217-227° range (had just been driving in some moderate/usual city traffic), since this car still has stock fan settings. Based on that, it makes sense to me that the PS cooler, located at the exit of the radiator, would be in the 19x° range (25-30° cooler) at that time. I'm sure temps would be considerably cooler if the car was moving at steady speed, but in city driving conditions you'll often find yourself stuck in slower moving traffic that allows coolant temps to really creep up. At that point, the stock "cooler" can become a "warmer".....until you can maintain steady speed for long enough that the cooler can actually begin a "cooling" process again. What's nice about the air-to-fluid style coolers is that you won't get the extra heat from creeping coolant temps while in traffic, plus you'll then get instant cooling just as soon as the car is moving again, vs. waiting for coolant temps to come back down after moving for a bit with the fluid-to-fluid style. If GM really wanted to cool these systems, they should have used an air-to-fluid style cooler to begin with.

Again, I think the stock cooler would work a lot better on a car with modified fan settings and even more so with a lower temp t-stat (plus modified fan settings). But those would be post-assembly modifications that GM was not counting on when they added the stock cooler. In completely stock configuration, it seems that the stock cooler wouldn't do much in stop-and-go city driving conditions.

wssix99

iTrader: (5)

Thanks

Agreed. When I took cooler readings, my fans were not running.


I wonder if the metal surfaces of the cooler are reflecting extra IR energy coming from the engine? The last time I did measurements, I saw wildly different readings from the hoses and their metal attachments.

RPM WS6

iTrader: (3)

I imagine it's also possibile that these readings just illustrate the greater tendency of metal to heak soak (vs. the rubber hoses). All the more reason why the factory cooler isn't very effective in conditions where coolant temps are allowed to reach maximum factory-intended ranges.

Chicagotola

This is a great thread -- I pretty much have everything I need to attempt this tomorrow.

One thing though: how do you flush the power steering fluid? I read you can run the car with someone pouring fluid in and one hose off. Which hose?

#5 or#7 in this diagram?

Chicagotola

That didn't post right...

http://parts.nalleygmc.com/showAssem...roduct=3064420

http://parts.nalleygmc.com/showAssem...roduct=3064420

wssix99

iTrader: (5)

#7 with two metal ends on it is the pressure hose. That never gets removed. #5 is the return hose, which feeds the low pressure fluid back to the reservoir. #5 is the one you want to take off and drain in to another container.

Watch out -
When you unplug the hose, the reservoir will drain on you. You may need to attach a temporary hose to it, so the reservoir will hold clean fluid during the flush. Also,the fluid drains out quickly in just a few seconds. Its a good idea to have someone ready to shut the car off if you can't keep up.

Chicagotola

I'm doing this today, and my plan is:

1. Install new upper radiator hose. Toss stock cooler in the trash
2. flush power steering pump (remove hose 5, start car, move wheels side to side while pouring in fluid)
3.Remove old power steering pump, install new one (install new serpentine belt while I'm at it)
4. Install external cooler
5. put power steering fluid in, and purge
6. Flush radiator with detergent product (Prestone super radiator flush) trying to get the oil out of the water, so my tranny cooler seals don't burst!)
7. Drink beer

demonspeed

iTrader: (7)

I'd suggest adding more step #7's.

To reiterate what was said above, the fluid drains very quick as soon as the car is fired up. When I did mine, I definitely had it go dry because I wasn't expecting to go that fast! I just filled the reservoir and moved the wheels back and forth until bubbles stopped coming up from the return. Steering feels fine with that method.

RPM WS6

iTrader: (3)

More data:

~15 miles of driving in city conditions with the usual combo of turns, traffic, and small areas of open road. Here were the conditions/results:

Car: '02 Z28 with aftermarket 17x9.5" wheels, 275/40 front tires, stock t-stat, stock fan settings. No PS cooler of any kind.

Temps:
- Outside air temp: 89°F (near record warmth for this time of year in Chicago....right after a frost warning two days ago....haha.)
- Road surface temp (per IR gun): 112-120°F
- Power steering fluid temp (in reservoir, per fluid thermometer): 186°F
- Power steering cooler surface temp (per IR gun, still located in radiator hose but disconnected from the PS system): 199°F
- Exit radiator hose temp (taken from rubber near the stock PS cooler): 184°F

As before, low speed fans were running when I parked the car.

In this instance outside temps rose by 12°, resulting in a 6° increase in PS fluid temp.

Chicagotola

Quick question: My Chilton says to pull the steering pump pulley off with a pulley puller first before removing it, but it's made out of fiber-reinforced plastic of some sort and looks dinky. Should I just try to reach the bolts without pulling it? The pulley does not have any holes in it to reach the boltheads...

I don't want to break the pulley -- looks pretty fragile...

Thanks!

Chicagotola

Nevermind -- I've got the wrong pulley puller- I've got the jaws style and need the steering pump-specific one!

demonspeed

iTrader: (7)

Here's a picture of the reservoir mess after an hour highway trip to the track and maybe three passes. Still not convinced the aftermarket cooler helped after my experience, anyway.

The Alchemist

iTrader: (19)

That's what my cap / resevoir look like as well, and I think it's a case of having a cap that is shitty, and doesn't seal properly. A screw on resevoir cap would work better.

RPM WS6

iTrader: (3)

This is interesting.

I've put at least a few hundred miles on mine since deleting the stock cooler (and NOT adding an aftermarket cooler), and I have seen no significant boil-over/leak-out mess....even after the ~90 degree weather of yesterday's test. All I've seen is just the slightest residue around the opening collar of the reservoir when I pull the cap off. FWIW, I used to have some residue like that before deleting the cooler, but I also had never taken the time to clean the area prior to that point. Over time, mine might re-develop that as well. It shouldn't be happening that quickly though. I would imagine that your air-to-fluid cooler is doing at least *something* to cool the fluid moreso than my coolerless setups (have you taken any fluid temp readings after a normal drive in hot weather?). I wonder if the seal on the bottom of your cap is going bad?

Additionally, my coolerless '98 never leaves any mess on the reservoir either, perhaps because it's a very low mileage car and the cap seal is still in better condition.

demonspeed

iTrader: (7)

I haven't taken any temp readings as I don't have a way to do so.

I might try tossing a new cap on there to see if that helps at all. While I don't have astronomical miles (just hit 69k on the way home from the track last night), I suppose that the car is 11 years old things just end up needed replaced.

I've really appreciated your updates, RPM WS6, as it's really putting this entire thread into perspective. While I'd have to agree the cooling should be doing something, I'm not sure it was worth it at this point. Perhaps if I had it located somewhere besides the bottom of the radiator support...