View Full Version : 80 Series PS Cooler??

08-14-2013, 11:48 AM
I recently sent my steering box to get resealed, and since everything is all pulled apart, I was planning on installing a power steering cooler. I ordered one up from amazon, (http://www.amazon.com/Derale-13260-Dual-Aluminum-Cooler/dp/B004XONQYG) and should be here soon. Plan was to replace the paperclip with this new cooler.

However, got to thinking after reading some other posts, I don't want to cool the fluid too much! My cruiser sees conditions anywhere from 100+ to -20, so now I am reconsidering my decision to put in an additional cooler.

Has anyone run a larger cooler on an 80 here, and if so, how did it work in the winter?

08-14-2013, 12:45 PM
It seems like all PS systems burn the fluid over time (based on its smell), but have you ever felt you really overheated the PS fluid to where you lost boost? I would think Mr. Toyota had this pretty dialed in, unless you're in Saudi Arabia. If you're see-sawing the wheel in a rock field regularly, then you may need additional cooling, too.

08-14-2013, 08:40 PM
I've been considering the same cooler myself. Can power steering fluid be too cool? I would not think so. I don't recall my steering feeling heavy at -30 starts in Summit County. Maybe my synthetic ATF is more cold temp friendly?

08-14-2013, 09:22 PM
its not the steering that feels heavy when the fluid is cold but the pump that cavitates that's the problem..

If it doesn't do it now when it's cold then it won't do it with a cooler. It won't get any colder. Usually the restriction of the cooler won't cause cavitation since the pumps pull from the reservior which should be full.

In my rig, the pump cavitates on starts that are -10 or below. I know it is bad, but those types of starts are rare for me (less than 20 times a year maybe?) and my pumps are cheap. I do know that without the cooler I was totally cooking the fluid after a few heavy wheeling trips before... it's also overheat and cavitate while wheeling.

For me, the tradeoff is good.

If it worked before for me (as in didn't overheat and cavitate while wheeling) I don't think I would have added one. I would be ok replacing burned fluid as long as it worked while i was out.

my rig has a saginaw pump and a stock 60 box with a tranny cooler that is probably 10x12 on it.

08-15-2013, 07:25 AM
Hello Corey, I have had one for close to 8 years on the Silver and red 93. While it is a single pass, not a double pass. I feel it has help and I have not had any issues with it in the super cold weather up at my house. I do feel that the summer time performance and the extra capacity in the system adds longivity to the ATF fluid when heavy off roading. I do think the initial bleeding can be a pain, getting all the air out to totally fill the system. I had to angle the out let a bit to allow full filling.
Anyhow, just my 2Cents.

08-15-2013, 02:26 PM
Thanks for the feedback everyone. Interesting points. I don't believe my pump cavitates during the winter. I do get some good noise on cold startup but I think that is the starter not retracting the gear quite quick enough. But now that I think about it I'm not too sure....:confused:

Interesting point about the fluid not getting any colder during start with or without the extra cooler. As long as the heat from both the engine and the pump/gearbox would sufficiently heat the fluid to keep it above that cavitation point during normal driving. I suspect, like mentioned above, that using a good quality synthetic ATF would help with this. (Valvoline Dex6 (http://www.valvoline.com/pdf/dexron_vi.pdf) had the 2nd lowest CST rating at cooler temps than other ATF's I looked at as well as regular power steering fluid. Mobile1 Syn ATF (http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil_1_Synthetic_ATF.aspx) had the lowest with a viscosity at -40c of about 10,000 cP. The M1 was almost twice the cost though...)

I don't really wheel hard enough or with big enough tires to have experienced cavitation before. I admit the thought of installing the new cooler is more a matter of convenience since the rest of the system is disconnected, and I had kinda viewed it as an upgrade (just not sure if its an appropriate upgrade for how I use the truck. :lmao: ) But if it kept the seals alive in the box and pump a while longer, it might be worth it.

I suppose I could always give it a try assuming I can get the paperclip out in one piece, and hold onto it and could always re-install if necessary.

08-15-2013, 04:08 PM
I recently sent my steering box to get resealed

What's involved in that?

Have you rebuilt the PS pump? Its easy. Internal leaks also cause cavitation and PS power loss.

08-15-2013, 04:24 PM
If it helps in your decision, I'll be installing one when I rebuild my pump...again. I've always heard that Synthetic oils were developed in Alaska because of the cold temps. Tested it in my snow plow's hydraulic ram with synthetic tranny fluid & it was awesome at (-20) temperatures.

08-15-2013, 09:01 PM
Just make sure the ATF is spec'd for Power steering pressures, I know that Dex/Mercon 4 is not spec'd for the high pressures of power steering systems, that is why most Toyota PS systems still spec Dex/Mercon 3.

08-16-2013, 07:47 AM
For the record, my stock PS system has had Mobil 1 synthetic ATF in it for 100K. Its on my PM list to change but I have not had any issues so it keeps getting bumped down.

08-16-2013, 07:50 AM
What's involved in that?

Have you rebuilt the PS pump? Its easy. Internal leaks also cause cavitation and PS power loss.

I have rebuild the pump within the last year or so.

Not much involved in pulling the box and sending it. Essentially removal of the low and high pressure lines from the top of the steering box, remove the ujoint lower steering shaft bolts, remove 4 bolts that hold the box on, remove the TRE.

Then I just drained as much fluid as I could, put it in a 5 gallon bucket with the pitman arm still attached (I couldn't pull it) and send it off to Texas with a sheet with work requested, address, etc. West Texas offroad has been floating around 'Mud for a while as a good place to send the box to. The price was VERY good and after chatting with both the front desk and the Tech, I was pretty impressed with them.

I initially had a bit of play in the box, not much leaking, but the play was kind of killer on the highway. I put this in my instruction sheet for them, and the guy called me back saying there wasn't much play in the box, but there was NO preload on it. This was after I had adjusted the set screw by about 1/2 turn, and then decided to let the experts mess with it so I didn't screw it up :D

Just make sure the ATF is spec'd for Power steering pressures, I know that Dex/Mercon 4 is not spec'd for the high pressures of power steering systems, that is why most Toyota PS systems still spec Dex/Mercon 3.

Good to know, thanks Robbie! I checked Valvoline's spec sheet for the dex6 and didn't see any info, so I sent them a quick email asking about that.