how to tell a good water pump from bad ?

[solarman216]

Keeping relevant to the thread, where does the viscous coupling draw it's heat from to operate the fluid clutch?

Actually it responds to the heat from the radiator, hence the coil bi metallic spring on the very front of the unit, when this attains the right temperature it opens the viscous valve, Rick

 

[rustic]

Actually it responds to the heat from the radiator, hence the coil bi metallic spring on the very front of the unit, when this attains the right temperature it opens the viscous valve, Rick

So what happens if the vehicle is stationary, will it then be the ambient temperature of the air, actually it does look like a heat sink, but in reverse.
Measuring the temperature around the fan unit.

 

[Smegg]

hola amigo, well thats my spanish done, the viscosity of the fan increases with heat and acts like a clutch, the best way to tell if the pumps had it is hold the fan blade wiggle it side to side you,ll feel atiny bit of play in the pump shaft this means the brass bearing inside has gone, there was a time when with a vice and new phosphate bronze bearing easy fix, well i feel really old now so i,ll bid you all a goodnight.

 

[solarman216]

So what happens if the vehicle is stationary, will it then be the ambient temperature of the air, actually it does look like a heat sink, but in reverse.
Measuring the temperature around the fan unit.

As you will be aware the fan still spins all the time so it is always sampling the hot air from the radiator so even stationary if the air gets hot enough the fan will start driving at water pump speed, which at no load idle will be more than enough to cool it down, as for the viscous fluid thickening when hot this is a misnomer, Rick

 

[rustic]

As you will be aware the fan still spins all the time so it is always sampling the hot air from the radiator so even stationary if the air gets hot enough the fan will start driving at water pump speed, which at no load idle will be more than enough to cool it down, as for the viscous fluid thickening when hot this is a misnomer, Rick

Thanks for the information Rick, as always I value your input. :thumb2 :thumb2

Best regards,
Richard, (Rustic)

 

[solarman216]

Thanks for the information Rick, as always I value your input. :thumb2 :thumb2

Best regards,
Richard, (Rustic)

And I yours, we all have our own bit to give, regards Rick

 

[rustic]

And I yours, we all have our own bit to give, regards Rick

So true, that's why I posted my computer query on here yesterday, got the answer in minutes and I was sorted.

As I have said before this club brings together all our own expertise that we are all willing to pass on to those, without the finer details of that knowledge.

We are collectively like the "Borg" we assimulate knowledge between us.


OK, sometimes that knowledge gets corrupted and we sometimes think we know the answer, ( Age and memory can be a major cause), when there is someone with more knowledge that can correct it.


Brilliant club. Mostly because of its' members. :thumb2 :thumb2 :thumb2

Best regards,
Richard (Rustic).

 

[JaG]

Overheat on low speed

I have just had a new viscous fan and pump fitted as the old one was leaking.
Went on a 20 mile run tonight and the temperature went up to 'normal' while doing normal speeds, whereas it normally only went up to 1/4. It remained constant throughout the journey.
Coming back there was deep snow so had to use 4WD and driving at around 15mph because of queue of cars. The temperature gauge kept going over 3/4 way up, then slip back to just over half.
Checked water (when it had cooled) and no blockage on front from snow.
Any ideas please.

 

[makeitfit]

I'd assume then that the viscous is doing it's job. As the temp rises the viscous engages and starts fanning the engine, cooling the old dear down Then at the right temp the viscous disengages again :thumbs
Have you changed the thermostat too? It's just that my truck will never go over half way till it's getting a right old thrashing?:augie

 

[JaG]

I'd assume then that the viscous is doing it's job. As the temp rises the viscous engages and starts fanning the engine, cooling the old dear down Then at the right temp the viscous disengages again :thumbs
Have you changed the thermostat too? It's just that my truck will never go over half way till it's getting a right old thrashing?:augie

Yes, changed the thermostat.
It concerns me that when it is running slow the gauge goes up to almost the red. It only slipped back when I increased the speed, not from the fan starting.

 

[makeitfit]

Check for air lock then. Also are you sure it's the right thermostat.
These engines are renowned for running cool :thumb2 Did you put anti freeze back in it btw ?

 

[JaG]

Check for air lock then. Also are you sure it's the right thermostat.
These engines are renowned for running cool :thumb2 Did you put anti freeze back in it btw ?

It has always run cool, until today.
I got about 3 miles out and it suddenly went from 1/4 to half in a minute or so, and stayed there all the journey, Never been up that high before.
I will check in the morning for an air lock. Just checked coolant and is perfect - full radiator and nothing missing from expansion tank. Puzzling!

 

[makeitfit]

and the anti freeze ?

 

[JaG]

and the anti freeze ?

Yes, they did that when they fitted the pump.
Just had to go out in it to pick up kids from town. Ran just below boil again. I will check the viscous fan tomorrow as well, even though it is new it may be faulty.

off to bed, will answer any further tomorrow.

 

[BIGSEAN]

Would be looking more at the cooling system itself, even if the viscous fan was buggered it would be unusual to get that hot, it hasn`t froze overnight has it?
or possibly lost coolant elsewhere? these trucks under normal conditions don`t get hot

 

[solarman216]

from an hour or two stopped, when starting again you should hear the fan for a minute or so then it quietens down indicating it is working, well sort of, if the bi metal spring on the front has not been crimped in correctly then the fan will not work no matter how hot it gets, so next time it gets hot listen for the fan noise you hear at start up, Rick

 

[JaG]

It's almost certainly the viscous fan because it is silent when you first start it and does not kick in at all, even when near boiling point.
Back to garage that fitted it tomorrow, it is only 2 weeks old!

 

[makeitfit]

I'm still puzzled how you're managing to get the temp up that high. I run my truck with elec fans and they simply dont come on for 11 months of the year there must be another issue here too.

 

[JaG]

I'm still puzzled how you're managing to get the temp up that high. I run my truck with elec fans and they simply dont come on for 11 months of the year there must be another issue here too.

Well, there is still the possibility it may be a faulty sender unit as it does not throw out water, or smell hot.
Puzzled why the viscous fan does not start for one minute as it should when the engine starts. There are no bubbles anywhere and everything seems OK elsewhere. I too am puzzled. I will post back when I get to know the reason why.
Thanks for everyone's advise and suggestions