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Category: CONSUMER PRODUCTS

Published on Tuesday, 07 May 2013 14:44

Written by Super User

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ABCs of Thermostats

Purpose of a Thermostat

The thermostat has two important jobs:

• Accelerate engine warm-up: By blocking the circulation of coolant between the engine and radiator until the engine has reached its predetermined temperature

• Regulate the engine's operating temperature: By opening and closing in response to specific changes in coolant temperature to keep the engine's temperature within the desired operating range

Parts of a Thermostat 

The basic parts of a thermostat are:

• Heat motor, which includes a valve attached to a piston that is embedded in a special wax
• Flange
• Spring
• Frame

Some thermostats also have a disk at the base that closes a bypass circuit inside the engine as it opens the radiator circuit.

• The bypass circuit circulates coolant inside the engine so that hot spots can’t form when the radiator circuit is closed. 

How a Thermostat Works

• When the engine is cold, the thermostats is normally closed; restricting flow to the radiator allowing the engine to “warm up”
• As the engine warms, the increase in heat causes the wax to melt and expand, pushing against a piston inside a rubber boot
• This forces the piston outward, opening the thermostat so coolant can start to circulate between the engine and radiator
• As heat increases, the thermostat continues to open until engine cooling requirements are satisfied
• If the temperature of the circulating coolant begins to drop, the wax element contracts; allowing spring tension to close the thermostat, which decreases coolant flow through the radiator

Thermostat Temperatures

• Thermostats have a “rated” temperature such as 180F or 195F
• This is the temperature the thermostat will start to open, give or take 3 degrees
• The thermostat fully open about 15-20 degrees above its rated temperature
• Many thermostats have a “jiggle pin” or “check valve” that allows trapped air in the cooling system to pass through the thermostat and be released from the system. 
• If a Stant thermostat does not have a jiggle pin, it will have a "bleed notch” or other method of removing air from the system.

Why is a Superstat Super?

Superstat premium thermostats have:

• Heavier frames and springs
• Larger heat motors
• Patented Weir valves

The unique Weir valve provides a higher flow of coolant to the radiator than any other thermostat on the market

• The early flow of coolant minimizes the “cycling” of temperature allowing the engine to run a steady temperature, resulting in higher efficiency.

Thermostat Failures

A thermostat fails “open” if the return spring breaks or debris prevents the thermostat valve from fully seating or closing; allowing a steady flow of coolant to the radiator, overcooling the engine

• This results in poor warm up and heater performance, increased engine emissions and reduced fuel economy
• An engine should never be operated without a thermostat, even in extreme temperatures

A thermostat will fail “closed” if the wax element has been damaged by overheating (from loss of coolant, a defective electric cooling fan or fan clutch) or corrosion

• This failure prevents the flow of coolant to the radiator, possibly overheating the engine and possibly damaging the engine
• When an engine overheats, it’s a good idea to replace the thermostat because it could be possibly damaged

Can a thermostat fail safely?

There is no such thing as a thermostat that will fail in a “safe” position.

• A thermostat will fail in either a closed or open position. 

One brand claims it fails in a safe position

• This brand locks itself open when it is a full stroke open position, basically breaking the thermostat.
• It does not spring open if it fails in a closed position.

OE & Alternate Temperatures

OE recommended temperatures should be used in nearly all situations

Alternate temperature thermostats are available and can be used in some applications

• Alternate temperatures are often applicated for older, pre-1995 vehicles where they can be used without causing problems
• Alternate temperature are not applicated for most newer vehicles
• Using an alternate temperature thermostat in a newer vehicle would require changing computer setting and possible additional modifications

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Category: CONSUMER PRODUCTS

Published on Tuesday, 07 May 2013 14:34

Written by Super User

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Save a Tank of Gas Per Year

If you live in a state that has regular emission control testing, you may have noticed that part of the test procedure includes an inspection of the fuel cap for leaks. While this may seem a bit trivial, a leaking or missing fuel cap can allow up to 22 gallons of gasoline per year to evaporate into the atmosphere. This hits you in your wallet as well as in your lungs through the air you breathe. Everyone knows that gas isn’t getting any cheaper and that 22 gallons of unburned hydrocarbons per leaking fuel cap contribute greatly to our air pollution problem.

The Clean Air Act of 1990 mandates emissions testing in certain states and metropolitan areas that don’t comply with minimum clean air standards. The penalty for not complying with these standards is a loss of government funds for highway construction and maintenance. Part of the emissions test procedure is to check the fuel cap for leaks. In states where mandatory emissions tests are required, you can’t drive without a properly functioning fuel cap. If during the emissions test your fuel cap fails, you are required to purchase a replacement cap, then have your car re-tested. This not only wastes fuel, but also wastes your time searching out a replacement cap and getting back in line for re-testing.

Historically while automotive exhaust emissions has been the focal point of government emissions regulations, the fuel cap has, up until recently, been largely ignored.

In 1970, California passed legislation mandating that all light duty vehicles sold in the state be equipped with evaporative emission control systems. These systems included special fuel caps with two-way valves, a pressure valve to keep gasoline vapors in the fuel tank, and a vacuum valve to allow air into the tank as it emptied. This regulation was adopted nation-wide in 1971.

This method of controlling fuel vapors at the cap remained essentially unchanged until 1996 when a new level of government regulations took effect. These new standards resulted in emission control limits 50 times more stringent than those of the past. New on-board computers in automobiles are now checking the entire fuel system periodically for leaks. If one is discovered, the "Service Engine" or yellow MIL light will illuminate. The car owner has no choice but to take the car back to the dealer for repairs. Often times the solution is to simply to turn off the light and correctly install or replace the damaged or leaking fuel cap.

New emissions standards have also resulted in new fuel cap designs. Since the mid 70’s the plastic threaded fuel cap was the standard type of cap for most light duty vehicles. The emission related problem with this design was that it could be "partially" installed by the consumer. That is, many times the cap was threaded into the neck but not fully ratcheted to the proper torque as required to create a proper seal. This partial installation can create a leak path triggering the "service engine" light. New "quick-on" design caps have reduced this problem. These new caps snap-on after insertion in the neck. The consumer cannot install the cap half way. It is either on all the way or not installed at all. Ford, GM and Daimler Chrysler have each adopted their own quick-on type fuel cap designs.

So it does not matter whether your car is new or old or if your car is equipped with an on-board computer. If you want to do your part for cleaner air and save money, replace and correctly install your fuel cap. Then we can all breathe a little easier.

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Category: CONSUMER PRODUCTS

Published on Tuesday, 07 May 2013 14:41

Written by Super User

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Stant Fuel Cap
Functional and Safety Features

Pressure Relief Prevents fuel vapors from exiting the fuel system under normal operating conditions Allows an escape path for pressure in an impact situation where the fuel tank has collapsed Permits pressure to escape in the event of a Vapor Management System malfunction such as a plugged vent line
Vacuum Relief Prevents fuel vapors from exiting the fuel system via the fill tube under normal operating conditions Allows an alternative path for air to flow into the fuel tank in the event that there is an obstruction in the Vapor Recovery and/or Vapor Management Systems Permits fuel system to normalize during natural vacuum situations  For example, a hot fuel tank being cooled down by a drive through car wash
Lost Motion During a crash the cap handle is allowed some freedom to rotate (from 60° to 180°) while maintaining proper O-ring compression Aids in the prevention of potential fuel leakage in a crash or impact
Torque Override Aids in proper installation of fuel cap Provides audible “click” for customer Allows for proper O-ring compression
Break Away Groove Allows for O-ring to maintain proper compression during a crash or impact even is some of the cap is broken away Prevents potential fuel leakage during a crash or impact

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Category: CONSUMER PRODUCTS

Published on Tuesday, 07 May 2013 14:30

Written by Super User

Hits: 176

Evolution of the Fuel Cap

Few drivers ever give much thought to a device on their vehicles which they use again and again - the gas cap. To most, it's thought of as little more than a plug which must be removed to allow the tank to be filled, then replaced. But, there's a lot more to gas caps than meets the eye. Current designs must meet a set of complex performance specifications which are much stricter than anything ever imagined just a few years ago.

This guide provides a brief look at the history of gas cap design as well as several key developments which affect gas cap performance today. The following outline highlights the key points.

Historical Developments

From the beginning of automobile production until 1970, gas caps were generally considered simply plugs to keep rain and other contaminants out of the gas tank. In most cases, they were simple unsophisticated metal caps although some were designed with vent holes to equalize the pressure between the outside atmosphere and the inside of the tank as fuel was drawn out. But beginning in the early 1970's two significant forces have driven the evolution of gas cap design: safety and environmental concerns. Safety concerns centered on keeping the fuel in the tank to reduce fire danger. The environmental concerns centered on the growing problem of contamination from fuel vapors which were escaping from the fuel systems and contributing to ground level ozone.

Key points:
In the early 1970's, Stant responded to fuel loss stemming from the positioning of filler necks lower on the fenders and to rear filler locations with new cap designs.

Around the same time, more attention was focused on preventing fuel loss from impact and rollover situations, protecting occupants from possible burn injuries or death.

During the next two decades, fuel cap design continued to progress and caps were developed which maintain the seal even if the crown is completely broken away.

Continual testing of cap design and construction is done at the Stant Technology Center using a variety of testing methods, including the pendulum and ball-drop to simulate crash situations.

In 1971, attention was drawn to the problem presented by the escape of hydrocarbon vapors and the first Federal requirements concerning evaporative loss were put in place.

Stant responded to the requirements with new designs which incorporated advanced pressure/vacuum valve technology.

By the mid-90's, the restrictions on evaporative loss were 50 times stricter than they were in 1971.

New designs and technology have been developed at Stant to meet the new requirements including:

• More positive attachment of the cap to the filler neck.      
• Caps that are easier to attach correctly.      
• New, more accurate venting systems.      
• Improved materials which resist deterioration from more aggressive fuels which incorporate ether, alcohol and other components.      
• Stant also developed the Prevent cap which allows pressure built up in the fuel tank on hot days to be released gradually when the cap is opened. This prevents fuel from erupting and spraying out on the motorist.

Onboard Diagnostics Systems (OBD)

As automobile makers came under increasing pressure to reduce engine emissions, they made significant advances in the ability of technology built into vehicles themselves to monitor correct operation of various engine and other related systems. These information processors, called Onboard Diagnostics (OBD) systems were first generation devices which could detect conditions which were outside of design parameters resulting in, among other things, higher than allowable emission levels.

A new generation, called OBD II, periodically checks the entire fuel system as the vehicle is operating, to ensure that inadvertent fuel vapor losses will not go undetected. That's important since poorly designed or missing caps can result in the loss of up to 30 gallons of gasoline per year. Even when a cap is mis-installed, it can cause the automobile's OBD II to trigger a "check engine" indicator light on the instrument panel notifying the driver that the vehicle needs service.

Key points:
In 1988, the state of California required OBD systems to monitor emission controls.

By 1990, the Clean Air Act amendments called for a new generation of OBD systems called OBD II.

OBD II systems test the fuel system by either pressurizing the system or applying a vacuum and measuring even slight changes which might indicate a leak and a possible loss of fuel vapors.

Gas caps are among the most critical components of the fuel system and if not correctly designed, calibrated and installed can cause the OBD II system to display a warning message to the motorist.

Stant caps have patented valve designs including special high quality, finely calibrated springs which allow the valves to open and close precisely, and meet OBD II requirements.

The "Quick-On" or 1/8th turn cap design assists the user in achieving a positive seal when installing the cap which helps avoid false readings and check engine lights during the OBD II system checks.

Specifications are so critical that non-original equipment caps are likely to fail to meet the OBD II test standard even though they may appear to be an exact replacement.

I/M 240

Another key clean air initiative has been testing vehicles to monitor their exhaust emissions levels. Those whose emission levels are over the allowable limit must be serviced and retested.

In some areas of the country, where ground level ozone levels are above allowable levels, emission testing may not be enough to lower the levels to meet Federal requirements. In those areas, a new, more stringent test procedure referred to as I/M 240 not only requires exhaust emission testing but testing of the fuel system for leaks as well. Since worn or damaged gas caps are likel

y sources of vapor emissions, the I/M 240 test process includes pressure testing the gas cap for seal integrity.

Stant offers three gas cap test devices which allow fast, accurate testing of gas caps to meet the requirements of I/M 240.

Key points: 
The Stant gas cap testers electronically compares the pressure integrity level of the cap being tested against a pre-set standard. If it meets or exceeds the standard, it is passed. If it does not, the cap must be replaced and the vehicle retested.

Fuel caps, especially those from suppliers who deal only in aftermarket caps, may appear to be direct replacements but may not meet I/M 240 test standards. That causes the vehicle to fail, in some cases even when the cap was purchased as a replacement when the original cap failed.