electric flex-a-lite cooling fan for SC400 HP gains

[jibby]

FAILURE ON THE SWAP!!!!!!! Today the Hydraulic pump bearing overheated and leaked ATF all over my engine bay, belt, electrical and just made a mess under my hood and I was lucky to make it home driving with a slipping serp belt and tranny fluid fying everywhere from Downtown LA...to Santa Monica... THERE IS NO WAY TO BYPASS THE HYDRAULIC FAN TOO FREE SPIN!!!!!! I repeat removing the vains is a load of horse crap!!! Now, I need to delete the hydraulic pump and pulley altogether, remove the fan tank and hose lines and install a shorter serp belt or quickly find a idler pulley that will stand in place of the Hydraulic pulley and bolt right on... The search is on, any help on the replacement idler would be most fantastic....

On a brighter note the electric fan works fantastic, a/c on in traffic in 90 degree weather today and the cooling was normal.. With the long running time today the still ATP fluid in the hydraulic pump over heated and the seals blew out....So kids don't try this at home...

 

[Damien]

That's a shame you've hit troubles Jibby - unfortunately it's always the way with doing something new. Whether you have electric fans or the hydraulic fan, the power to run them still has to come from the engine and way back when engine fans always ran at engine speed electric fans were great at modulating how and when they draw power but these days they seem to be a solution in search of a problem.

You only need to look at the cost that has gone into the hydraulic setup to wonder why Toyota chose that over cheap electric fans. If you're going for forced induction and need the space that would be a different story.

Good luck resolving the pump issue but try to not do anything that isn't reversible in case you want to put it back to stock.

 

[jibby]

Damien - Hey don't get me wrong I actually love the electric fans and the swap. I have no regrets other then maybe not getting larger electric fans (16" blades). I also have a relay switch mounted inside my car that can allows me to shut the fans down when needed. So there is no fan drain on the engine when racing...and can turn it right back on after...So you may want to reconsider that first paragraph of yours. So there are hp gains to be made regardless of what people say, space to be freed, and looks better too... This next move will still be an improvement from before, so it is not all for lost....Removing the fan tank, pump, hoses will look even nicer... Just a little upset over the time I spent on going this route when it was all for not..but it's really no biggie...just delays my header install that's all...See ya

 

[Damien]

Cool mate - if you're happy that's all that matters : )

 

[stevechumo]

Hey John,

I feel bad for the pump getting overheated. I believe when removing the star valves inside the pump, it doesn't have enough pressure to suck in enough fluid from the fluid reservoir, although it's mounted up high. Therefore, the little amount of oil inside the pump stored too much heat and expanded itself thus blowed out the seal. The other alternative to this modification is to use a new pump seal, put the pump valves back, and keep the fluid cooler just like before. The fluid cooler mounted behind the front bumper will definitely extract a lot of heat from the system. This is the most easiest and effective solution to your current setup. And of course you'll still use the electric Flex-alite fans.

Damien,

I agreed with you why Toyota chose the hydraulic fan for the SC400. But I'd also like to add a few thoughts to your statement. Toyota chose the hydraulic fan was because the SC400 is a luxury car and the car has to be quiet. And Toyota didn't care if anyone would modify their cars in any way for turbos or superchargers. Otherwise, it wouldn't cost $50K U.S for this car when new. However, other model Lexus use the electric fans such as the 2nd generation GS300, '98-'00 or maybe later model. I'm not sure about GS400 but it could also use the electric fan.

Bests,

 

[jibby]

Thanks for the thoughts Steve. As you know I am stubborn and refuse to go backwards, pump deletion is the call....besides I want no drain on the engine and running the hydro pump even with out the fan push will still cause drag...I believe I will run a shorter serp belt for now and remove the pump then monitor for slipage, studying the belt pulleys and all I believe there is enough grab on the crank pulley for this to work, plus a few other guys on this forum are running in that fashion. Just a little concerned when the nos kicks in and the crank turns over quickly and immediately, I may get minor belt slipage with about a 40% belt grab drop off from stock...

 

[WDoherty]

Jibby there may be an easier solution to this. Before i bought my 92 sc400, i bought a 97 sc400 and ended up not going through with the deal cause there seemed to be some shady stuff goin on. Anyway i test drove it and it had electirc fans. I am assuming these were stock. This would mean, as mentioned somewhere else in this forum, that you could find a 1uz that was not equiped with the hydralic set-up and should find a plate with an idler on it, or something like that. Anyway, you'll have to research and find out what years had the electric fans, but all i know is i drove 97' with electric fans.

 

[jibby]

WDoherty, I looked up info on this, someone mentioned a newer LS400 but there is no writeups or testimonies of any compatible idler swaps that have been made. I know the Aussies have the replacement idlers and I see it on their posted engines. Nothing here in the States from what I can see so far. My plans are to use the shorter serp belt for now and then take my time and find a swap idler that has been proven to work. Or just leave the shorter belt in place if it works. One other member says the shorter belt works fine with no slipage, and has had it that way for a longest time, so I think I will be good...Thanks for the heads up......

 

[SCV8]

I have done a similar thing to another car, and the power steering pump, as it was, worked fine without the vanes, plugged, as long as the right quantity of fluid was used to compensate for the expansion that occurs when heated.

I also used a motor oil with some moly additive, since there's no reason to use hydraulic fluid any more, and the motor oil doesn't expand like ATF will.

 

[jibby]

Problem solved, gave it a little thought and came up with this: Unscrewed the power supply and sensor to the hydro pump, left the sensor intact..then removed the face of pump by removing the six screws. I picked a threaded hole on the right side of the pump to drill,tap and fit a larger hardend bolt to hold the uni. bearing idler. Here are the pic's you can figure out what I did pic by pic... Let me know what you think? Took me twenty minutes and $40 to solve the problem. No need to remove the pump, rework the stud, fluid in the pump, non of that crap.. It could have been this easy all along....man.....

Just need to fit the serp belt and make a nice looking plate cover for the ugly face of the hydro pump.. I chose a small bearing idler so it will have belt clearance, a larger idler would not have worked. The idler can be purchased at any auto parts store for $20..I also used my plumbing sleeves to fit the offset for the belt, but could have used washers. This all fits tight and snug and freespins. The threading goes deep into the pump so there is alot of metal to work with, this is a solid setup. Hardened bolt, locking washer and thread locker. Also, it is very easy to drill thru a pre-drilled smaller hole, tapping and threading the pump is so easy...An angled drill will be needed if you don't want to remove the radiator for drilling clearance...That is it!! Pump deleted....should not have any further problems...

 

[jibby]

Final post - I unpluged the hydro pump to disable it. However in doing so that inturn gave my ECU a bad read, I got a few idle stalls and when floored the oil light came on. I used a 10ohm circuit loop at the unplug point to correct the problem. I got this circuit from my EGR delete kit from LEX, and XIR, I am hoping I can get a replacement... Anyway final pic's of the extremely successful fan swap... I love it...

 

[stevechumo]

So are the oil light still on and the engine still stalling after the resistor is plugged? I hope there's no more problem and am eager to know.

 

[jibby]

Oil light doesn't come on at all, and no problems what so ever to report after the loop. The loop is working perfectly and seems to work the same as it would with the EGR block... I was really praying for this to work, and it did I finally caught a break with these mods...

 

[jtjerry]

looks as 10k-ohm 1/2 watt rezirtors rulez in 1UZFE
same can be use for fool egr stuff as hydro stuff. thats good. congrat on your project!!!! looks good!
Jerry

 

[stevechumo]

looks as 10k-ohm 1/2 watt rezirtors rulez in 1UZFE
same can be use for fool egr stuff as hydro stuff. thats good. congrat on your project!!!! looks good!
Jerry

10k-ohm resistor seems to be too much. Are you sure of that?

 

[jibby]

I was told it was 10ohm resistor, but I do not know for sure. This came in my EGR delete kit... I need to find another one. I am going to run this little circuit by a local auto electric shop down the street and get the low down...I will post back with 100% accurate info...

 

[jibbby]

Steve, take a look at this thread as you should be notified via email as you posted on this thread...This pretty much covers my entire fan swap...Good luck on your swap and hydro pump deletion it is alot easier then you would think..

 

[stevechumo]

Thanks, John.
You're right that deleting the hydro pump is alot easier. I actually had planned out all parts necessarily with keeping the pump and its hoses. I still think deleting the pump and putting in a new pulley is still a lot easier and more efficient than keeping it and its hoses. However, I'm still hesitating due to the oil light coming on sometimes. That's kind of bothering me. :no:

 

[jibbby]

The oil is drained and the pump sensor reads the pump as having not any oil...The sensor has no effect on the engine operations and or bad ECU reads...Trust me Steve it is no big deal..The sensor reads the oil and that is it....If you trick those sensor wires you will not have the light come on at all...I have not tried that...something to consider... Saving the pump and keeping the oil inside will only cause you trouble....I was thinkiing the same way you were.....The oil light flashes on and off only on hard turns and or stops or hard launches... If you think that is bad try headers, I got a stall once or twice already at idle and the check engine light remains on all the time....It is time to remove a couple of cluster bulbs because my cluster this is not a Christmas tree and it is not Christmas yet.:tongue2:

PS. I removed the 10 ohm loop as it didn't matter either way as shown on the picture above...I removed that whole wire assembly...Again no effect on the ECU that wire just powers on and off the pump cylinoid....So there is a sensor and the power supply wire to the pump...Delete them both and you will be fine...

 

[jibbby]

Final conclusions - I have been running this fan setup for almost a year now, the electric fans are cooling as good as stock, the idler pulley is working like a champ, no stalls or foul ECU reads to report or trouble...No looping or tricking of sensors is necessary...