Auto Repair & Maintenance Articles


Brake IQ
Detecting Bad Hoses

Tune Ups

Shocks & Struts

Oxygen Sensors 


Check Your Brake I.Q.


How long is one second? About as long as it took to read the last sentence; exactly how long it takes to cover an 88 foot stretch of highway at 60 miles an hour.  Imagine, at that speed, encountering a panic situation that demands immediate braking. You may need another second or two-using up at least 100 feet-to react to get your foot to the brake pedal.  Then, all going well, a few hundred feet further down the road your car will come to a stop. 


Depending on the reaction time, the type of vehicle and several other factors, including the mechanical condition of your car, you hay have traveled several hundred feet from the time you first encountered the situation until you're safely stopped.

A frightening scenario! In fact, a national survey of motorists discloses that loss of braking would be the worst possible mechanical crisis a driver could imagine.

Not surprisingly, says the Car Care Council, brake failure is the leading mechanical cause of highway accidents. To heighten consumer awareness about the vital vehicle system, the Council offers this multiple choice brake safety quiz.


1. You feel the brake pedal pulsate as you come to a stop. The reason may be:
a. worn brake pads.
b. overheated brake fluid.
c. warped front rotors.
2. Your car steers to the right when you apply the brakes. The reason could be:
a. a sticking left front brake aliper.
b. low fluid in the master cylinder.
c. a defective parking brake pulley.
3. What is ABS?
a. Air Bag System.
b. Anti-Lock Brake System.
c. A computer system acronym.

4. Your brake warning light goes on. The most common trouble:
a. a leak in the hydraulic system.
b. a leak in the vacuum system.
c. worn brake pads or linings.
5. A common early warning sign of brake trouble is:
a. a harsh scraping or grinding sound when brakes are applied.
b. the pedal falls to the floor when brakes are applied.
c. the wheels lock when the car is driven in reverse.


1. (c) is correct. The wobbling surface of a warped brake rotor will cause an uneven or pulsating action as you stop.
2. (a) is correct. The faulty action of the left brake causes stronger braking on the right side. The result, your car wants to dart in that direction.
3. (b) is correct. ABS is an acronym for anti-lock braking system. Anti-lock brakes are designed to prevent skidding and help drivers maintain steering control during an emergency stopping situation.
Determine if your car has an anti-lock braking system by noting whether an ABS light flashes on your dashboard during ignition, checking your owner's manual, or asking your dealer.
4. (a) is correct. When you see your brake warning light go on, go directly to a technician to find out what's wrong and have it fixed.
5. (a) and (b) are correct. The harsh noise indicates excessive wear, leading to damaged drums or rotors and eventual brake failure. The falling pedal means a problem in the hydraulic system; you're about to lose your brakes.

Questions like these are contained in the 90-page Car Care Quiz Book. Published by the Car Care Council, the illustrated book has informative text plus 110 questions and detailed answers covering the car from bumper to bumper. It's available for $5.95 from the Car Care Council, Dept. BOOK, 42 Park Drive, Port Clinton, OH 43452.


Tune-Ups...High Tech TLC For Your Car


When the family car gets sick you probably worry about it. You're anxious to get Old Faithful into the shop, where you'll find a technician trained to diagnose its symptoms. His diagnostic equipment may look like the props from a science fiction movie but that's often what it takes to locate the trouble in today's complex, computer controlled vehicles, says the Car Care Council.

High-tech methods not with-standing the human element still must prevail. The service personnel generally do their best to maintain a high level of customer confidence, to treat every vehicle as if it were their own.
Performance problems in a late model car can be like human malfunctions except the car has several "brains," about a mile of wire and a complex system of sensors. Computers may play a role in numerous functions, including starting, steering, braking, climbing a hill, changing the inside comfort level and on and on. Micro-processors can turn on the lights, tune the radio, report how many miles until the gas tank is empty and, in some cases, lead the driver to his destination.

When any of the above functions and others fail, your technician turns to a computer to diagnose and correct the problem. Eventually he or she may tackle the repair with hand tools (special, of course) and the repair generally isn't likely to be a speedy one because of the crowded conditions under the hood.

Today's vehicles, despite their complexity, require far less maintenance and repair than their forefathers, says the Council. Unfortunately, as in the case of high-tech medical care, training and equipment don't come cheap.
Our cars not only are thinking for us, in some cases they can diagnose their own problems. With the help of computerized test equipment, trained technicians can locate and correct most driveability problems that, only a few years ago, would have eluded the best of them.

Urging motorists to recognize and act on signs of pending car trouble, Car Care Council offers a pamphlet entitled, "The Eight Most Common Signs Your Car Needs a Tune-Up." For a free copy, send a stamped, self-addressed envelope to Car Care Council, Dept. T, 42 Park Drive, Port Clinton, OH 43452.


Give a Good Squeeze To Detect A Bad Hose


Until recently, the most common method of checking engine coolant hose was to visually inspect its outside cover for signs of wear, or "ballooning" under pressure. This method is no longer considered completely reliable in light of research that proves most hoses fail from the inside out.

Damage starts inside

During four years of field tests on fleet vehicles, engineers for The Gates Rubber Company identified the primary cause of coolant hose failure as an electrochemical attack on the tube compound inside the hose.

The phenomenon, known as electrochemical degradation, or ECD, produces fine cracks, or striations, in the tube wall. These fine cracks extend from the inside to the outside of the hose tube, near one or both ends of the hose. The coolant seeps through these cracks and attacks the hose reinforcement as it wicks along the length of the hose. The condition eventually results in a pinhole leak or a burst of hose at failure.

ECD is not peculiar to any one automotive manufacturer, but is evident in almost all cooling system hoses. The most severe damage occurs where the temperature is hottest and air is present with the coolant, which is why upper radiator hoses tend to fail first.

Like oxidation, ECD is accelerated by driving habits that increase the heat history of the coolant hose. Therefore, engine hoses that are subjected to any extended amount of stop-and-go, or engine idle, show earlier and more severe electrochemical damage.

The "squeeze test"

The best way to check coolant hose for the effects of ECD is to squeeze the hose near the clamps or connectors using the following procedures recommended by Gates:

1. Make sure the engine is cool.
2. Use fingers and thumb to check for weakness, not the whole hand.
3. Squeeze near the connectors. ECD occurs within two inches of the ends of the hose-- not in the middle.
4. Check for any difference in the feel between the middle and ends of the hose. "Gaps," or "channels," can be felt along the length of the hose tube where it has been weakened by ECD.
5. If the ends are soft and feel mushy, chances are the hose is under attack by ECD. To avoid breakdowns, replacement is recommended.

Replace four-year-old hoses

A replacement interval of four years for all coolant carrying hoses--especially the upper radiator, bypass and heater hoses--can help prevent unexpected failure from ECD. The incidence of hose failure increases sharply after four years for most vehicles.

Earlier hose replacement is recommended for fleet vehicles such as taxis, police cars and delivery vans that are subject to significant stop-and-go driving and the resulting high engine and coolant temperatures.
Electrochemically resistant (ECR) hose has been developed by Gates engineers that resists the destructive effects of ECD. This stock, which is expected to evolve into the industry standard, carries the ECD-resistant properties of silicone hose, without the susceptibility to punctures and tears.

In fleet tests in the toughest applications, ECR hoses have gone 200,000 miles and are still going with no electrochemical damage. Standard hoses reveal damage and failures as early as 20,000 miles in the same fleet tests.



Shock & Struts
More Than Just A Comfortable Ride


What Shocks & Struts Do:  Shock absorbers and struts do more than just provide a comfortable ride. Their most important function is to influence the control and handling characteristics of your vehicle. Without them, a vehicle would continually bounce and bound down the road, making driving extremely difficult. Shocks and struts are designed to help keep your tires on the road. They control the action of the spring to resist bottoming out . . . like when you hit a pothole . . . and keep the movement of the springs under control when they rebound.


How Shocks & Struts Work


According to the experts at Gabriel Ride Control, shocks provide resistance by forcing hydraulic fluid (oil) through valves in the piston as it moves up and down. Because the oil cannot be compressed, only a certain amount of fluid can be forced through these valves, which creates resistance to the vehicle movement. Premium shocks and struts are superior to regular hydraulic shocks because air in the shock is replaced by pressurized nitrogen gas. This advancement in technology prevents bubbles from forming in the hydraulic fluid. These bubbles, called foaming, reduces the ability of shocks to provide resistance and prevent bounce. Gas shocks also quicken the response of a shock's movement thereby increasing comfort and control under all conditions.


How to Tell if Shocks & Struts Need Replacement


Under normal conditions, shocks & struts wear out gradually. However, many factors can affect how much wear is actually occuring and at what rate it is occuring. For example, 2 people buy the same vehicle new off the dealer lot, one lives in the city close to the office, and drives mostly on straight roads. The other lives in the country, 45 miles from the office and must travel 10 of those miles on a winding, often muddy gravel road. Because shocks operate in extremely hostile under-vehicle environment, where anything from gravel to ice, and snow to grit can affect the life of the product, it is a good bet that driver #2 will need to replace his shocks long before driver #1. The piston rod can easily be nicked or damaged by flying gravel allowing grit and dirt to damage the piston seal. When this occurs, fluid begins to leak from the piston seal and eventually the shock will lose its ability to function properly.

Worn shocks and struts not only affect the ride comfort and control of your vehicle, but can affect its braking effectiveness, too.  Here is a good self test to check for signs of worn shocks or struts:


Do you experience excessive bounce (3 or more bounces) when crossing an intersection or dip?
When stopping quickly, does your vehicle rock back and forth several times?
While applying your brakes firmly at higher speeds, does your vehicle have a tendency to drift left or right?
When changing lanes quickly does your vehicle rock or sway from side to side?
On a tight curve like a freeway ramp, does your vehicle lean and sway giving it an uneasy and disconnected feeling?


Many components contribute to the handling characteristics of your vehicle. Having your vehicle inspected if you experience any of the above signs is good preventive maintenance and can help parts wear less and last longer.


When inspecting shocks and struts, your service technician will look for:

  • a badly leaking shock or strut. The unit is losing fluid and can't provide the resistance it was originally designed for. 

  • Shiny Spots at the contact point of the safety bumper, and marks between the coils of the spring called "coil clash". They are the result of topping and bottoming caused by excessive suspension travel.

  • Tire cupping around the circumference of the tire can be caused by worn or ineffective shocks & struts.

  • Broken or loose shock or strut mount. The product is not solidly connected at both ends and cannot function properly.

  • Broken or damaged piston rod. The product cannot function properly and should be replaced.

    Oxygen Sensors 
    A Key Component Of Your Vehicle's Performance
    by Robert Bosch Corporation


    With the sophistication of today's increasingly computerized auto-mobile engines, it's become difficult for the do-it-yourselfer to service or tune-up the engine on his own vehicle. And along with this computerization come new parts that are crucial, both for optimal engine performance and also to stay within the bounds of environmental laws regarding engine emissions.


    The oxygen sensor is one of those crucial components. They're roughly the size of clothes pins, yet many people don't even know they exist. But they play a pivotal role in monitoring engine exhaust, one of the most common causes of air pollution.

    The first oxygen sensor was introduced into automotive engines in 1976 (on a Volvo 240) by The Robert Bosch Corporation.

    The oxygen sensor is a measuring probe for determining the amount of oxygen in the exhaust. It continually monitors exhaust gases and signals the engine computer to adjust the air/fuel ratio to ensure that gasoline combustion is as complete as possible, thus reducing harmful emissions while also improving engine performance and fuel efficiency.

    In fact, replacing a degraded oxygen sensor with a new one will increase fuel efficiency by 10 to 15 percent.
    Oxygen sensors also play a key role in ensuring that vehicles pass the new emissions inspection programs that will be required in many states due to the Federal Clean Air Act.

    "Studies show that two thirds of all vehicle emissions test failures are a result of worn out oxygen sensors," explained Chuck Ruth, Bosch general product manager. "Those numbers are staggering when you consider that oxygen sensors are easy enough to replace and that the vast majority of them are also inexpensive, costing roughly $20 to $50."

    "Even if you're not a do-it-yourselfer, it's a good idea to have a professional service technician check your oxygen sensor on a regular basis: every 30,000 to 50,000 miles for an "unheated" 1 or 2 wire sensor or every 60-100,000 miles for a "heated" 3 or 4 wire sensor. When the oxygen sensor is degraded, you can very quickly recoup its low replacement cost from the fuel savings of up to $100 a year resulting from complete combustion and a smoother running engine."

    How can you tell if you need a new oxygen sensor? Common symptoms of a worn out sensor include excessive fuel consumption, high emissions, engine surging or hesitation, or premature failure of the catalytic converter. When examining the sensor, a shiny deposit on the sensor's heat shield or any gummy deposits indicate it's time to check and/or replace the sensor.

Local:  (603) 692-4848     Toll-Free:  (800) 692-4849     Fax: (603) 692-2886
20 Main Street, Somersworth, New Hampshire  03878