Fan going thou radiator in water crossing's

[Tropical Low]

My Dad's got a 2005 3.4 V6 Hilux. We'v gone thou 2 radiators now from go'n thou water and no mater how carefully he go's thou it keeps happing 0.4 m deep or 1m. Toyota say's it just the way it is. where after idere's on how to shop it from happing?:crazy:

[SimonW]

There are a couple of articles about water crossings in the latest 4WD Action issue.

From memory some of the ideas were...better driving/crossing technique, car bra, thermo fans you can isolate for crossing, remove engine fan or disable fan clutch (if possible) for crossing, etc.

[stets]

if you have an electric fan set up in your lux, run a bypass switch, basically cut into the power wire, run some wire to your switch in cab, then run some more back out to the power wire. this puts a power stop in your system, just make sure that you only use it for water crossings though as you can overheat very quickly without your fans going

[toy yoda]

an over ride switch like stets is talking about is a great idea...but be warned...watch how you wire it.. a thermo fan draws large amperage, and may have a relay in the system oem to facilitate the high amps.....by cutting into the power wire on the fan you are then running max amps through a switch all the time ( bar your water crossings) ,, eventually the switch WILL fail..you WONT get any warning and your fan will just stop..then i hope your a gauge watcher or youll need to invest 6k into a new motor!!!

Either trace the orig wiring properly, then cut & place your ""stets" switch on the trigger wire....or simply run a new relay using the power wire at the fan as a trigger..and put your switch on the earth wire at the relay!! 30-battery ( fused).....87-thermo..... 86- orig thermo power ........ 85 earth ( via switch)
the 85 and 86 terminals have minimal power draw now, so switching is safe!!

[Tropical Low]

Thanks guys for that, but it's got a viscis hub fan some one say's to drill a hole thou fan bald and fan cowling and tie wire thou to shop fan in water crossing and keep rev's down dont know?

[toy yoda]

i had the same on my old cruiser..and have done for years......i use an occy strap....then again i used to just stick my hand in and grab a blade on a running motor for a party trick ;)

[minisman]

yeah you can just use an occy oran old/spare fan belthooked to a blade and another non moving part while engine is stopped, then start it up again.

or you can wire in some electric ones with a thermo switch and manual override switch. should cost around $200 at a guess.

[Richard]

Thanks guys for that, but it's got a viscis hub fan some one say's to drill a hole thou fan bald and fan cowling and tie wire thou to shop fan in water crossing and keep rev's down dont know?

Done a couple of radiators as well and was tying off the fan blade with a bit of rope, no hole. Worked out what was causing the problem and a new prototype bash plate seems to have resolved it.

[howesy]

If you say it does it even in 400mm of water then its probably the bow wave pushing through the radiator and then the blades act like paddles and as they chop through the gushing water they draw closer to the radiator until OOPS.

Get a tarp and tie it to the chassis rails underneath and up under the bonnet and tied off again. A paced steady crossing should have the water diverting around the fan. Think about it I'm sure you have seen someone do it before.

[Peter @ Aawen4x4]

Don't whatever you do drill a hole in the fan blade!! They get brittle enough anyhow, and adding a hole WILL have bits of fan blade breaking off! But the concept of stopping the fan IS the way to go!! Even if it's electric or switchable, as you drive thru water (or the water flows thru the radiator) the fan will turn, and if it turns enough it can hook up the straps that hold the radiator together, hook into them and tear them out and your radiator is cactus. If it's running as you go thru water, you stand a good chance of cactus radiator, so stop it running!

Viscous coupled fans are great for this, only take a long shoelace, doesn't need to be ultra strong, just make a loop in one end that will fit snugly over a blade, loop it on and slide it right down to the base of the blade, then looking carefully at which way the blade will turn or try to turn, tie the other end of the shoelace or cord off on something that won't move, and in such a way that it keeps it clear of any rotating fan belts etc. Do that immediately before you drive thru the water, drive thru, out the other side, making sure that you ease out to dump water as you go rather than taking a couple of tons of water up the bank, drive clear of the exit, pull over and take the shoelace off. If you've done it right you won't need to stop the car to take it off, you can just pull the loop up the blade of the fan and clear - fan starts spinning and away you go!

Viscous coupled fans will usually manage being held stopped for a few minutes without any issues, and your car shouldn't heat up in that time frame, especially if you are driving thru water! BUT, if your fan hub is on the way out, or you drive off and forget that it's there, you may end up overheating. The fan hubs will usually loose silicone over time and just get worse, rather than stop instantly, so you should know when one is getting bad, especially if it performs worse after tieing it back like that for a few minutes. If you stop the car and can see silicone fluid where it's been sprayed out of the hub onto the surrounding fittings, then you'll know it's time for a re-fill with silicone, and replace the 'O' ring while you're at it. If the bearing or bearing seal is gone, sorry, you'll hafta replace the fan hub - I don't know of anyone who replaces bearings or seals in the hubs themselves.

But all up, tieing back the fan is the best way to go - even if you do all the car bra type things, you should STILL tie the fan to stop it propelloring forwards into your radiator or hooking up the fixing straps. Doesn't matter what make of car, if it's got a viscous coupled fan - tie it back!

Cheers!

[gtir300]

Peter thats great advice and well explained

Not that I do many deep water crossings, i read the article and was dubious to tying up the fan blade, favouring removal of the fanbelt, but your explanation makes good sense. I may give it a try for a few mins in the garage before I have to use it out on the track.

[Tropical Low]

Thanks alot for that well explained info Peter. That sounds like the way to go mate. My dad will like that idear:thumb:And thanks to all with there info!