Vicous Fan Test

Submitted by Stalin1878 on

Forum: 

I've searched the site and couldn't really find what I wanted to know, the search function isn't that great Blum 3

I want to know how to check if my viscous fan is working. I looked in the manual and it says there is 3 stages of "locking" the first is at 62c and I can't remember the others. When the engine is cold, you can turn the fan reasonably easily, but it will not spin by itself. I drove the truck into work and got it to normal temp/just above, opened the bonnet and stopped the engine, before I even got to turn it by hand I saw it continue to spin freely on its own once the engine was stopped. I could then spin it with one finger and it would rotate on its own for a while with very little resistance.

The reason I want to check it is because on the way back from Tamworth on Sunday, while over taking a convoy of caravans at 70mph I noticed the temp go up to 3/4, higher than I've seen it go before.

Thanks for your help, Ben.

Reading those things it does

Submitted by Stalin1878 on

Reading those things it does look like something is wrong with mine, seeing as its stiffer when cold than when hot.....

guess its just me

Submitted by JollyRoger on

but my fan kicks in from start up so have never had a problem... could a previous owner set it up to do that?

Locked up rad fan

Submitted by ews on

Hi

The vicous coupling may have been locked up, this can be done with insertion of a thin layer of cardboard, between the fan body , where the oil normaly resides, or by drilling an bolting to fix the unit as one piece or that the unit has rusted up and locked in permanelty.

The fan problem is a regular subject re Fourtraks, hence the post indicated, for rebuilding / oiling the unit

Edward (ews) '92 Fourtrak 2.8 TDX

I took mine to bits and

Submitted by mowerman on

I took mine to bits and looked at the spring pin, incidentally you can test this is free by putting a smal screwdriver against the tab in the centre and twisting slowly, if the pin is free you can see it move back and forth.
However as I couldnt find anything wrong with mine and it did get very hot today towing on a 20mile journey I decided to lock it up. I did this by sparating the 2 halves (needed the old impact driver for the screws!) and inserted apiece of inner tube rubber, cut in a circle to just drop in.
It has locked it up well, so will see if its effective...

cheers

Rob

Locked up fan

Submitted by ews on

Hi Mowerman.

Have you found an increase in noise due to locking up the unit, and has it been effective

Edward (ews) '92 Fourtrak 2.8 TDX

yeah, it roars alot more, but

Submitted by mowerman on

yeah, it roars alot more, but only did it last night, and not been out to work in it yet...overheating only gives a problem on long runs, and dont do those very often, so will have to wait and see.

cheers

Rob

UPDATE - I ran the truck with

Submitted by mowerman on

UPDATE - I ran the truck with the fan locked up and it didnt go as well, it made a load of noise and didnt help the cooling much, so I took the 'stat out and flushed the engine and rad, then without putting the stat back in I removed the Viscous fan and fitted a pair of Diacl cooling fans, which I separated and put one on the front of the rad and one behind.
These are on a manual switch at the moment, but these combined with the stat removeal have completely cured ny overheating. In fact with no stat in and the locked vicous fan the temp gauge NEVER moved, which is why I have fitted the leccy fans.
Now it is quieter, cooler, goes much better and is running great

cheers

Rob

its OK cos I took the viscous

Submitted by mowerman on

its OK cos I took the viscous fan off, so it does warm up OK now.
I thought of that though, and may shove a bit of board down the front of the rad to blank it off in winter.
Wont use this truck much in winter - I'm a gardener!

cheers

Rob

well, its a hack of alot

Submitted by mowerman on

well, its a hack of alot noisier!!
You dont have to worry about rattly engines or anything cos all you can hear is this jet engine roar!!
I will have to put a leccy one on with a thermostat when i get round to it, but it will do for now

cheers

Rob

just been out to look at mine

Submitted by mowerman on

just been out to look at mine - as you say when cold it wont spin all the way round by itself. I assume this is normal. I have 2 others in the shed, one is the same but the other spins with no resistance at all, so I would assume this is U/S.
Not sure about when hot - the links didnt really answer the question for me

cheers

Rob

When it comes to temperature on a diesal fourtrak..

Submitted by If theres mud i... on

These engines get hot in the summer, if you read the manual/booklet with a fourtrak, it says/states the engines get hot in summer, your fan probably isnt an issue, check to see if you can see through the radiator so its not a birds nest making it warm, second have you got anything in the way of the rad apart from grill i.e big lights/winch etc, third is it the water pump??, but last and what i would say is most important to actually check take the cover of and look at the thermostat-this i bet wants changing, as replacing it fixes most temperature issues.

Full of ideas but no time to do them!!

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I've check the stat and it is

Submitted by Stalin1878 on

I've check the stat and it is fine. The rad looks ok, a little dirt but I will wash it out this week. I do have 2 spots in front of the grill, buy they have been on there for 2 years and I havn't seen it get hot before.

The main reason I ask about the fan is that, as I said, it is harder to turn when it is cold than when the engine is hot.

taken mine off and put on a

Submitted by loftyborofan on

taken mine off and put on a electric fan on a switch from a rover 200, bigger and hopefully better

2 inch body lift,
2 inch suspension lift
sj steel rims
31x10.5 tyers
volvo radiator and expanstion tank
upgraded hoses!
vw polo 1.3 supercharged webber carb

to do
snorkel designed just to fit

I had mine on a manual switch

Submitted by mowerman on

I had mine on a manual switch - but kept forgetting to switch it on!!
So I fitted a cooling fan thermostat from ebay, but left the manual switch in as an override for wading

cheers

Rob

Where did you get the fan

Submitted by Stalin1878 on

Where did you get the fan from Mowerman?

Where did the Rover 200 fan come from, scrappers?

I will post some pics in the

Submitted by mowerman on

I will post some pics in the gallery of my fan setup - the fan is about 12" I think...

cheers

Rob

EDIT

Submitted by Stalin1878 on

EDIT

When I got into work today I popped the bonnet and stopped the fan with an old window sponge I found in the cab. The engine was at working temp(gauge at half-way), so I think it should have been at least at the first stage of locking(60c). I don't want to mess around repairing it unless I have to, I want to try and get/fit an electric fan and some kind of auto switch to turn it on, can anyone help me with which fan will fit/which switch will work?

Many thanks.

Impressive setup Mowerman.

Submitted by Stalin1878 on

Impressive setup Mowerman. Your stat looks good, apparently you can get inline stats for those, although you would have to pick one temp and stick to it. They are not adjustable like yours.

You wouldn't have thought a 1.2(petrol?) fan would have been enough for a 2.8...

How did you attach the fan to the rad ect?

Thanks for pics!

its only a 1.6 petrol mate,

Submitted by mowerman on

its only a 1.6 petrol mate, Sportrak.
I drilled the shroud and then used good old cable ties, I know Kenlowe do thin ties you actually push through the rad to hold it, but I just put them round the rad and fixed them to where i could.
It works great - I was surprised myself!!

cheers

Rob

yes got it from a scrappers,

Submitted by loftyborofan on

yes got it from a scrappers, off a scrapage deal car, so i kew it was driven when it came in?

2 inch body lift,
2 inch suspension lift
sj steel rims
31x10.5 tyers
volvo radiator and expanstion tank
upgraded hoses!
vw polo 1.3 supercharged webber carb

to do
snorkel designed just to fit

Fluid coupling...

Submitted by baz elzebub on

...on my Sportrak also seems to never lock up, so this evening, I unbolted the unit & played with it to see what's what.

Rather than open up the casing (screws were too tight!), I found that by using the tip of an electrical terminal screwdriver, you can carefully lever out the fixed end of the coil from its casing seat, by lifting it a little, then flattening it back down several times. Obviously, you need to be careful not to over-exert or the coil might snap, but eventually, it popped out of the groove, and after gripping the pin top with fine-nosed pliers and twisting it a little, it worked loose and rotated correctly. I re--seated the coil end in its groove, tapped it in with a screwdriver handle, then gave it a quick splash from a boiled kettle - hey, presto! Around it went, then retracted as it cooled!

Fingers crossed for when I refit it tomorrow - I'll let you know how it goes (just servicing the Sporty for a little green-laning fun on the Isle of Man, this coming week; "Anti-roll bar? Didn't have one, Occifer...")

Baz.