How do I know if my viscous fan is working?
How do you know if its working properly? When your motor is hot, you should be able to hear the fan kick in. If you can't, pop the bonnet, and turn the vehicle off while watching the fan. If it comes to a fairly abrupt stop, the fan hub is working properly.
Which fluid is used in viscous coupling for fan?
Contains 18ml of 10000Cst silicon fluid. This is the replacement viscous fluid used when servicing your viscous fan clutch.
What is a viscous clutch fan?
Viscous fan clutches are belt-driven and found on many older rear-wheel-drive passenger cars. They contain a drive and driven plate with annular grooves that fill with a thick viscous silicon fluid. These fans are needed at slow speeds, typically below 35 mph and at idle.
How does a clutch fan works?
A fan clutch is a thermostatic engine cooling fan that can freewheel at low temperatures when cooling is not needed, allowing the engine to warm up faster, relieving unnecessary load on the engine. As temperatures increase, the clutch engages so that the fan is driven by engine power and moves air to cool the engine.
How much oil do I put in a viscous fan?
Often after many years of use, you may find your viscous fan is not performaing like it used to. Sometimes its as simply as adding oil to your viscous hub. Typically your hub will require between 1 and 2 bottles of oil.
Is a fan clutch necessary?
The fan clutch is one of the most essential components in the operation of cooling fans and greatly contributes to the overall operation of the engine. While many new vehicles use electric cooling fans, many older vehicles utilize a mechanical fan clutch to help control the fans.
What happens when fan clutch goes out?
The fan clutch controls the operation of the cooling fan, and if a fan clutch goes bad, it may not engage properly or at all. As a result, it will disable the fans or prevent them from working at maximum efficiency, which will lead to the engine overheating and more severe issues if left unattended.
What controls the fan clutch?
The air temperature passing through the radiator is sensed by the bi-metal thermal spring on the front of the thermal fan clutch. It expands and contracts with the change in air temperature operating a valve inside of the clutch.
How does a fan clutch affect AC?
A locked up fan clutch will not reduce A/C cooling efficiency. Reduced airflow across the condenser generally affects the ability of the condenser to cool the refrigerant, resulting in higher temperatures and pressures in both sides of the A/C system.
Can fan clutch cause overheating?
Overheating engine is the most common symptom of a bad or failing fan clutch. It controls the operation of the cooling fans. These cooling fans will disable/not work at maximum efficiency as the bad clutch will not engage properly. This result in overheating which may lead to serious issues if not timely attended.
How do you adjust a clutch fan?
2:465:05Adjusting temperature on viscous fan clutch - YouTubeYouTubeStart of suggested clipEnd of suggested clipThis little it's going to try to rotate this little hub in there counter clockwise. So more counterMoreThis little it's going to try to rotate this little hub in there counter clockwise. So more counter clockwise that. It goes then the more open it is which means your fan turns on more.
At what temp does a clutch fan engage?
At what temperatures do fan clutches engage? Answer: Most fan clutches engage at about 170°F air temperature (about 180-190°F engine temperature). They reduce the temperature about 20°F before disengaging.
What is the difference in fan clutches?
The primary difference between them is in the “Working Area”. As a fan clutch spins, it creates heat. The larger the working area the easier the heat is dissipated. Due to the larger working area, the Severe Duty fan clutch runs cooler providing a longer life expectancy.
What is the difference between a thermal and non thermal fan clutch?
A non-thermal fan clutch is nothing more than a thermal fan clutch always partly engaged. It provides adequate cooling when needed, however, it does not save you money by disengaging (operating at a lower RPM) when additional cooling is not needed.
Are electric fans better than Clutchfans?
Flex fans don't use a clutch and therefore operate at 100 percent of water pump speed, making them more efficient than clutch fans. Considered a step up from clutch fans, these fans are typically lighter than clutch fans and often feature blades that flatten out at higher rpms for greater efficiency.
How much is a fan clutch replacement?
If the fan clutch isn't working properly, your fan won't spin at the proper speed to provide the necessary cooling for your car. Depending on your vehicle's make, model, and year, a fan clutch replacement might cost you anywhere from $200 to $400.
How does the fan drive viscous coupling work?
Its rotor is connected to the crankshaft pulley using a belt drive. A disc with an impeller is connected to the rotor through the working fluid. Wh...
How to understand that the viscous coupling is faulty?
The only sign of a faulty viscous coupling is overheating of the motor, and the fan does not spin. In this case, the gel may leak out, the coupling...
What is the viscous coupling for?
The viscous clutch is designed to temporarily connect one set of discs to a master set. The viscous coupling of the cooling fan provides cooling of...
What is a fan clutch?
Depending on the temperature of the coolant in the engine, it changes the fan speed. When it heats up, the clutch increases the fan speed.
What happens if a viscous fan is off?
On the other hand, if the viscous fan connection fails in the off position, it will not allow air to pass through the radiator. This, in turn, will lead to overheating of the engine when the cooling process stops.
What is a viscous fan coupling?
The viscous fan coupling is one of the lesser known components of the engine cooling system.
Where is the viscous fan clutch located?
The viscous fan clutch is located between the pump pulley and the radiator and performs the following functions:
What can a faulty viscous coupling lead to?
A faulty viscous fan clutch can remain stuck in the engaged position, which means it will always run at 80% of engine speed. This can lead to breakdown with high levels of noise and vibration, creating a loud vortex sound as the engine rpm increases and fuel consumption increases.
Why are long haul trucks using a viscous fan?
Here are five reasons why: 1. Viscous fan drives deliver only the amount of cooling needed – nothing more, nothing less.
Why are viscous drives good for cars?
But by holding oil in the reservoir when the engine isn’t running, viscous drives can help vehicles start up faster in cold weather.
What is a viscous clutch?
A viscous fan clutch can cool a truck, tractor, construction machine, power generator or mine hauler’s engine with a similar amount of flexibility. Viscous drives control how fast an engine fan spins with remarkable accuracy.
What does it mean when a fan drive is lower?
3. The lower a fan drive runs, the less noise it creates. That means a more comfortable experience for an operator. But it also means complying with noise regulations that continue to tighten as the world’s population becomes more urban.
Can you replace a viscous drive?
On-offs are also simple to replace, although viscous drives have a long shelf life too, with many coming maintenance-free.
Is a viscous fan better for the environment?
Viscous fan drives are just plain better for the environment. Every time an internal combustion engine runs, particulate matter is created as a biproduct of the engine cycle. But proper cooling can limit it and thus significantly decrease carbon emissions.
What is viscous coupled fan?
The viscous-coupled fan makes use of a natural property of fluids which is that a liquid has only a limited tendency to stick to itself, a tendency which is greater in proportion to the thickness of the liquid.
How to remove a viscous fan?
After slackening the fan belt to relieve the strain on the system, the fan and its viscous-coupling can be removed by undoing this single bolt . Depending on the amount of clearance present you may have to remove the radiator first. If the bolt seems unusually tight, try turning it clockwise; the bolt may be on a left hand thread to prevent it from being thrown loose by the running of the engine. On re-assembly it is a good idea to apply a little locking fluid to the bolt to prevent it vibrating loose. Having removed the whole unit, the coupling can be separated from the fan blades by undoing a ring of bolts which join the two components. Replacement is the simple reversal of the dismantling procedure.
How to remove a fan from a radiator?
When small engines are fitted into large engine bays there is often a cowling to duct the air through the radiator and on to the fan. This is generally a simple, light device located by small bolts or self-tapping screws to the radiator surround or nearby bodywork and can be removed fairly easily. The next step is to slacken off the fan belt. The bolts locating the fan blades hold the fan pulley in place as well, so slackening the belt reduces the strain on them. Then remove the blades, but remember which way round they go for when it comes to replacement. In common use was a nylon version of the simple fan. It was generally moulded in a single, multi-bladed unit, and was slightly flexible to make it less prone to damage from flying objects. It was fastened and removed in a similar fashion to the metal unit.
What type of fan is used in a classic car?
There are four principal types of fan that will concern the owner of a classic car. The most widely used on post-war cars was the simple belt-driven fan which operated whenever the engine was running. There are two basic modifications of this design. One incorporated a viscous coupling, while the other was controlled electro-magnetically. These both had the advantage of operating only at slow engine speeds. The fourth type of fan was the electrically-driven fan operated when necessary by a thermostatic switch.
How does an electro-magnetic fan work?
The electro-magnetic fan performs the same function as the viscous-coupled fan but in a more complex way. It is operated by a temperature-sensitive switch which is located in the base of the radiator. Above a certain temperature it switches current through a carbon brush touching the back of the water pump pulley. This brush bears lightly on a coil of wire and with current flowing through it, it becomes an electro-magnet. The fan, in front of this pulley, is pulled by the magnet and clamps to the pulley and begins turning with it. With the fan in operation the water temperature obviously drops. When it reaches a certain point the thermo-switch is turned off, the electromagnet cuts out and the fan separates from the pulley and freewheels to a halt. Being rather complex there is quite a lot that can go wrong with this system.
How does a water pump fan work?
Generally it is bolted directly to the exterior of the water pump and driven by the same belt which also drives the generator or alternator . This classically simple arrangement was used for decades because it was simple, cheap and relatively trouble-free. The major cause of problems with this set-up was a loose or broken fan belt. The V-belt drove the fan through a pulley system by friction, consequently, as the belt stretched through wear, it could start to slip. Tell-tale signs were overheating in traffic, as the fan and water pump were not turning at the correct speed. If the belt also drove the generator a final warning would, on older cars, be a red ignition light coming on indicating a failure to charge the system, but the belt may have been loose for some time by then.
What does it mean when a fan fails to turn?
If the fan still fails to turn, it indicates that the fault is in the fan motor. The electric motor will be held firmly in a frame and shrouded by a cowl. You should first disconnect the battery then remove as much of the covering as necessary to remove the electric motor.
How does a thermal fan clutch work?
A thermal fan clutch reacts to temperature of the air rushing over it from the radiator. As the radiator heats up, the air passing through it also heats up. This heats up a small bi-metallic coil in the face of the fan clutch, releasing an internal valve.
Why is a fan clutch important?
A properly-functioning fan clutch is critical to engine reliability, as it works to maintain a safe temperature range. A failing fan clutch could leave you stranded with expensive repair bills, so pay attention to these symptoms. Here, you can see where the fan and fan clutch are driven by the engine. Morio / Wikimedia Commons.
What happens if a fan clutch leaks?
If it leaks out, the clutch will weaken and eventually fail. Check fan speed. You should be able to audibly detect when the fan clutch engages, with an accompanying rush of air. At idle, as engine temperature increases, a thermal fan clutch will engage at a certain temperature.
What is fan clutch?
An electronic fan clutch functions similar to thermal and torque-limiting types but isn’t modulated directly by temperature or speed. Instead, the engine control module (ECM) or fan control module uses various sensors to determine when to engage the fan clutch, such as at engine idle, low vehicle speed, air conditioning compressor engagement, or above a certain engine temperature threshold.
How many types of fan clutches are there?
There are three types of fan clutch, depending on the vehicle’s design. A small amount of resistance always keeps the fan spinning, but it’s basically free-wheeling until the fan clutch engages. When the fan clutch engages, it spins up greatly, increasing air flow through the radiator and over the engine.
What is a fan belt?
Nearly unheard of on modern cars with electric engine cooling fans, people sometimes still refer to the accessory drive belts as “fan belts.”. This term harkens to the day when cars and trucks used drive belts to drive the cooling fan or water pump. The engine cooling fan, made of plastic or metal, isn’t hard-connected to ...
Why does my fan make a loud noise?
Excess fan noise at high speed is caused by the same problem, a seized fan clutch. This can cause bearing damage, radiator damage if the blades flex too far, or even shatter a plastic fan.
What is a fan clutch?
Unsourced material may be challenged and removed. A fan clutch is a thermostatic engine cooling fan that can freewheel at low temperatures when cooling is not needed, allowing the engine to warm up faster, relieving unnecessary load on the engine. As temperatures increase, the clutch engages so that the fan is driven by engine power ...
Where is the fan clutch located?
When the engine is cool or even at normal operating temperature, the fan clutch partially disengages the engine's mechanically driven radiator cooling fan, generally located at the front of the water pump and driven by a belt and pulley connected to the engine's crankshaft. This saves power, since the engine does not have to fully drive the fan.
Do front wheel drive vehicles have a fan?
This is why electric engine-cooling fans are used virtually universally in front-wheel drive vehicles. The conversion of mechanical energy to electricity and back to mechanical rotary power with a fan motor is less efficient than a direct mechanical connection, but this is more than compensated by greater control of an electric fan through electronic thermostatic controls which can turn the fan completely off when the engine temperature is below the setpoint.
