Brakes maintenance

Inspecting of brake systems

Checking and maintaining your car brakes is a very easy job and it does not require technical knowledge. Maintaining car brakes involves three basic procedures:

1. Inspecting them for damage and wear
2. Replacing linings
3. If required complete overhaul or replacing of a part that fails.

Every car owner should inspect his brakes to see that the linings do not wear out prematurely. Most brake problems develop gradually and can be detected by inspecting the brake system. Most lining replacement simply involve removing of a few mechanical parts replacing the worn out brake shoes or pads and reassembling them. Replacing a leaking brake hose or hydraulic cylinder is a straight nut and bolt job. Bleeding the brakes afterwards to expel the air from the system is usually a two-man job but not at all difficult. The power boost brakes either work or fail completely. If the vacuum or hydraulic systems that produce the power are connected and not leaking, repair is a matter of removing the power booster and exchanging it for a new or re-built part and reinstalling it.

It makes sense to remove the brake drum and check the shoes, at least once a year. Such inspections make it easy to tell how much useful life is left before it requires replacement.

When it is possible, the car may be placed on top of a repair ramp to take a close look at the brakes from under the vehicle. Check for leaks on or around the brake parts. This can range from the brake fluid to the axle wheel. The brake shoes should be free of oil and grease contamination.

Now jack up the wheels one at a time and remove the wheel for inspection. If your car has disc brakes, examine the pads to see if they are worn out and require replacing. The face of the pad should show even wear. If not so, there may be a problem with the brake caliper. It is now advisable that you consult your mechanic.

On drum brakes it will be necessary to remove the wheel drum to see the brake shoes. If you ever drive through mud or water, it is a good idea to wash out the brakes with water so as to flush away any dirt or sand. It is also a good practice to replace brake fluid once in two years to avoid master cylinder corrosion caused by condensation of water vapour in the brake fluid.

Top    

Tyre Wear

As the face is the index of the mind, the condition of the tyre is an indication of the condition of the car and of the way you drive. If one can read tyres, then the future of the car can be predicted. To take it further, the treads are like the lines in one's hands and a good palmist can soon predict the Doomsday.

THE WAY YOU DRIVE

Application of common sense will tell that sudden brakes and high acceleration will in turn apply brakes in the effectiveness of the tyre and accelerate the tyre wear. A sudden brake might cause a flat spot in the tyre. This will happen when the wheels lock and the car is dragged like this for some distance.

Sometimes, when constantly driven at high speeds, the rubber of the tyres might soften due to the heat generated at that speed. This might result in parts of the treads being flung away from the tyre. What this means is that the tyre is not fit for high speeds or rough handling. Then there is always our friendly neighbourhood Indian road. They will assist in bringing about a swift end to tyre. So stick to the maxim right tyres for the right roads and extend the life of your tyre.

CONDITION OF THE CAR

Pressure not only affects humans. It also affects the tyres. It is a common belief that reduced pressure improves the road holding. But on the contrary, it doesn't really help in rainy days, when the danger of hydroplaning increases. On the other side, increase in air pressure causes wear in the middle of the tyre. Therefore having the right pressure is always good for the life of the tyre. When checking the air pressure, check when the car has not run too much, like in the morning. If the car is well run, then it will show a higher value than actually is.

If run constantly with incorrect air pressure, it will result in uneven wear. Under inflated tyre will wear off the edges, while over inflated tyres will reduce the centre tread down to its bones.

If extra wear occurs in several places, then check the brakes. They might not be correctly adjusted. If extra wear happens in one spot of the tread, then the wheels might be badly balanced. Bad wheel balance or even a fault in the suspension, steering gear or bearing will cause uneven wear.

Anything that is stuck to the tyre or that has pierced the tyre like a nail, should be removed immediately and appropriate steps has to be taken to lessen the damage that the foreign object can cause.

Finally check the air pressure regularly; at least once a week, for even a tubeless tyre will lose air.

Top      

Wipers and Washer

Wipers keep the windshield clear in bad weather and are essential for safe driving. For the wipers to work efficiently keep both the windshields and wipers clean by washing them once a week. Clean the inside of the windshield as well to maintain good visibility.

The squeegees are that part of the wiper system that actually cleans the windshield. They are made of rubber. Air pollution time and weather affect this rubberized portion and hence they should be replaced every six to twelve months.

To test the squeegees wash the windshield and the squeegees with mild and warm soap water. Rinse thoroughly and wet the windshield again. Now run the wipers through a complete circle. If they skip or skid, replace the squeegees with new ones.

The blade assembly should distribute pressure evenly along the entire length of the squeegees. If the mental is bent or the swivel joints are corroded, then the wipers may miss sweeping some areas of the glass and may need replacement. Wiper arms contain tension springs that exert the correct pressure on the blade. In case the spring is damaged or broken, the arms must be replaced.

The common windshield wiper problems are smearing, chattering and water beads.

Washers: To clean the windshield adequately, not only wipers but also the washers must be in good operating condition. Basically all windshield water systems contain a reservoir to hold the washing solution, a pump operated either by an electric motor or rarely by foot, nozzles to deliver the spray to the windshield, and the tubing to connect the nozzle and the pump.

If very little or no washing solution is delivered to the shield when operated then first check if the reservoir contains enough solution. Sometimes washer failure is caused by kinks in the tubing or when dirt clogs the system. Straighten the kinks and clean the system thoroughly. But in case the pump becomes unserviceable, replace the entire system with another pump.

Before taking off on a long drive or trip, be sure to check both the wipers and the washer - both should function well enough to render your shield clean and clear.

Top    

Clutch

A clutch is a devise, which disengages the engine from the transmission when the clutch is depressed so that the gears in the manual transmission can be shifted smoothly. Part of the clutch is attached to the engine flywheel and part to the transmissions input shaft. When the clutch pedal is released, both the potions of the clutch join together and the flywheel and input shaft rotate as one piece.

The clutch pedals are seen in only manual transmission vehicles. In automatic transmission cars it may be noted that no clutch pedals are provided, as there is no requirement for them.

CLUTCH PEDAL FREE PLAY

In cars where clutches are provided you need to ascertain the clutch pedal free travel periodically. As the clutch wears from normal use the free play travel is used. If not adjusted, regularly there is a possibility of partial disengagement and this results in slippage and premature clutch failure. Hence the periodic adjustment is required. If the clutch starts to disengage, when stepping on it, then it should be adjusted to give free travel (which is the distance from the top of the pedal as you step on it to the point where it starts to disengage the clutch.) This distance should be somewhere around 18-22 mm.

However there are two types of clutches. They are

Cable operated clutch linkages ii. Rod-operated clutches.

In the cable operated clutches adjustments are made by screwing adjusting nut in or out of a threaded fitting at on end of the cable. There are locking devices holding the adjustments. Adjusters may also be found at the pedal or clutch-operating fork. Rear drive cars must be rained to get at fork adjusters on clutch housing. Front drive cars can be adjusted from under the hood as can rear drive cars with adjusters.

In the rod-operated clutches push-on levers instead of pulling-on cables to remove the clutch fork is utilized. This system is usually found on the larger and older cars that require strong linkage. All common rod linkages adjust by a threaded rod that is secured by in one or two adjusting or locking nuts. The adjustment is made at clutch housing under the car on the drivers side. First measure the free play at the pedal if it is insufficient, raise the front end of the car and support it safely. Spray locking and adjusting nuts with penetrating oil and clean off the dirt before attempting to make adjustments. When the clearance is correct, lock the adjuster.

Top      

Differential Transmission and Transfer Case Fluid

Every six moths or so, the level in manual transmission should be checked and oil added if necessary. There is a dipstick in automatic transmissions, but in manual you will have to remove a metal or rubber filler plug and check the level with your finger. Always use the oil that is recommended by your user manual.

Checking oil in differential should be carried out every six months and in case of necessity oil can be added. The procedure is essentially the same as for manual transmission. In a front wheel drive car, the differential is housed with the transmission in a unit called transaxle. In manual transmission the manual requires only one lubricant and has only one filler hole. The transaxle in automatic transmission is lubricated separately. Most carmakers do not recommend any oil change in the differential unless the car has been subjected to unusually heavy use. Always use the recommended lubricant as specified in the manual. Special lubricants are used in limited slip differentials so you must first confirm whether or not your car has a differential of that type.

Only when you know what to look for can you check the condition of your differential transmission (and transfer gears in case of four-wheeled drive) i.e., what is more important is the condition of the fluid and not the level. On most of these drive trains, the fluid is checked at the plughole half way up the differential housing or cover plate. The oil level is just to the bottom of the hole. Stick your finger in it and get enough on it to see if there are any metal particles in the oil. If so, it can cause the bearings to fail and seals to leak.

Timely repair can save a lot of money as well as avoid a major breakdown. The metal particles are probably from the gears put under a heavy load. Hence it is prudent to completely change the oil.

Be very careful about the oil used on the transfer case - some vehicles of foreign make use ATF (Automatic Transmission Fluid) while others use heavier oil. If transfer case oil is low and transmission is overfilled, internal is indicated and you should consult your technician soon

Top      

Fuses

Commandos do a job similar to that of a fuse, protect or die trying. The Fuses used in automobiles are made of a glass-enclosed strip of having a low melting point alloy metal. If the fuse "blows" or self-destructs, a circuit overload is usually the reason; the protection of the wiring and the components it serves is guaranteed as it does allow the excess current to touch it. Each electrical system, in newer automobiles, has its individual electrical circuit (e.g. for the headlights, parking lights, wipers, audio, cigarette lighter, etc). A series of exclusive fuses usually, is the best bet to protection from shorting or overload of the main fuse link. Five to twenty five Amperes is the range of these fuses.

WHAT TO DO WHEN A FUSE BLOWS: -

Properly clean the fuse holder if fuse is still serviceable.
Ignition switch and other switches must be turned off.

REPLACING: -

The fuse must be replaced with one of the same value (for convenience specific color codes are present for specific ampere values or the fuse rating of each fuse is specified on it). If this new fuse also fails as soon as it is fitted, short-circuiting may be the reason so check again the wiring of the components. To find the point of fault it is necessary to switch on other accessory switches and see which one blows, then replacing it. The wiring or accessory parts may be faulty so need to be closely investigated.

OTHER REASONS FOR FAILURE:-

There may be corrosion, it may be unclean or may have been displaced by the motion of the automobile. The holder may be tightened or the fuse may be cleaned well to restore the circuit.

Substitutions for fuses are both unsafe and unreliable and should be avoided as much as possible. Some use silver paper around a match or a blown fuse, but if there is even a slight fault in the wiring of the circuit or component, there could be disastrous complications.

Top      

King Pins and Wheel Bearings

The wheel of a car is normally made of stamped steel parts that are welded together. However wire wheels and one piece cast or forged aluminum wheels are also available as an option on many cars. The wheel is made up of two parts called the rim and the centre. The wheel centre is offset to one side to make room for suspension and brake components. It is attached to the hub by bolts with conical heads called lugs. The mounting holes in the wheel centre are also conical so that the lugs or lug nuts can position the wheel accurately. Ventilating holes in the wheels help to keep the brakes cool. The wheel hub is fitted over a ball or roller bearing on which the wheel rotates. It serves as a mounting plate for the wheel itself and for the brake disc or drum. The roller or ball bearings reduce friction so that the wheels on a car turn freely. Tapered roller bearings replace ball bearings in wheel hubs because rollers can handle heavier loads and higher speeds. However improved ball bearings are again replacing the rollers in modern hubs.

To check the kingpins and bearings in any vehicle, the front and rear of the vehicle should be raised up by jacking. When the front wheels are jacked up, tightly hold the top and bottom of the wheels with both the hands and try pushing or pulling it. If the wheel moves it may indicate some wear and tear in the king pins or steering knuckle. It is also possible that the wheel bearings are loose. Now rotate the wheel to check for noise. Disc brakes may show some drag because they rely on wheel wobble to move the pad away from the rotor. However in a drum brake type, the wheel should rotate smoothly without noise. In case you hear something suspicious, consult your mechanic

Top      

Maintaining Door Hinges

When I was just a sweet little boy my grandma tied my shaky tooth to the door of our car and slammed it shut. Imagine the agony! Since then I have had many a door slammed in my face by a number of good lookers and they have only aggravated my hostility towards doors in general.

Door hinges require periodic lubrication to keep them operating properly. As I unwillingly discovered, the operation of doors is not as simple as it may seem and to get a grasp of the same, one need to know the various parts of he door.

Each door has two hinge assemblies: one on the top, called the upper hinge (brilliant man was he who named that...) and one on the bottom, called the lower hinge.

Each hinge assembly has two basic parts: one attached to the body and one attached to the door. Most hinges are bolted to the door and body (kindly bear with the boring details). The bolt holes may be slotted to allow the door to be moved slightly for proper alignment. A round pin called a hinge pin is solidly attached to one side of the hinge assembly. This pin fits into holes in the other side of the hinge assembly.

When the door is opened or closed, the hinge assemblies rotate on the hinge pin.

Here's something practical for you to do...lubricate the space between the hinge pin and the hole that it rides in, for the hinge to move smoothly.

One of the two hinges is usually equipped with a door check. The door check is used to hold the door in an open position after the door is opened.

The door check has three basic parts: a door check cam, a door check roller, and a door check spring.

The door check roller is attached to the body side hinge. The roller fits into grooves in a cam that is attached to the door side of the hinge. When the door is opened the cam moves and the roller rolls on it until the roller fits into one of the grooves. With the roller engaged in a groove, the door is held in an open position. There are several grooves, which means there are several positions for holding the door open. The door check spring holds the cam and roller in contact with each other. The door check roller and the slots in the door check cam each require periodic lubrication for proper operation.

The door latch assembly on a car door is another area that requires periodic lubrication. The door latch assembly holds the door closed and allows it to be locked.

The parts of the door latch assembly that you see on the outside of the door are the door handle and the part the key fits in, called the door lock cylinder.Most of the door latch assembly parts are located inside the door at the opposite end from the hinges.

Operating the door handle moves a linkage rod, which in turn opens and closes the latch mechanism on the part of the door called the door jam. The latch mechanism must be strong enough to hold the door closed even if the car is involved in a collision (you wouldn't want to spill out now would you?).So play safe...

When the door is closed, the latch mechanism engages a part on the car body called the striker. The striker is mounted to the body pillar. Some strikers are a stud (like moi!!) or bolt that the latch mechanism engages like the one shown below. Speaking of nuts and bolts reminds me of a cool pick-up line I tried recently...

" You must be a spanner cause when I look at you my nuts tighten."(haaaa...worked for me)

Back to serious business... other cars use a part called a striker plate, which the latch mechanism can engage.

The door lock cylinder allows the driver to lock the door. The lock cylinder and related parts fit inside the door. When the key is inserted into the lock it slide into the lock cylinder (ooo baby!!!).

Turning the key turns a pawl at the end of the cylinder. The pawl engages a connecting link to the door latch assembly. When the lock cylinder is in the locked position, the connecting link prevents the door latch mechanism from operating: the door cannot be opened.

Lubricate, lubricate, lubricate.... The door hinge and lock mechanism should be on your list every time the car is serviced. A door hinge assembly that is not properly maintained will result in a noisy, hard-to-operate door. An improperly maintained lock mechanism will result in locking and unlocking problems

Top       

The Exhaust System

THE BASICS

The exhaust system of a car transports hot, poisonous gases from the engine out side the car where they can be released into the atmosphere without danger to the car's occupants. The system also reduces the sound of combustion, and usually contains a catalytic convertor - a chemical reaction chamber in which exhaust pollutants are converted into less harmful substances. Burned gases are released from the combustion chamber, with great force, several times a minute with high pressure. Super sonic shock waves ricochet through the exhaust manifold. The muffler breaks up or absorbs the pressure waves reducing them to legally acceptable noise level. The water and road alt eat away at the exhaust system from the outside. Water and acid vapour in the exhaust gases eat away from the inside the pipes and mufflers. A point to note is that city-driven cars used for short trips will need more frequent muffler replacement than a car used for longer trips.

TROUBLE SHOOTING

Engine faults can often be detected by observing and listening to the exhaust system. An irregular exhaust note can be caused by ignition defects or incorrect carburetor settings. Sooty exhaust smoke may indicate too rich a fuel mixture or failure of an injection system. Excessive blue smoke when the car is accelerating shows that oil is leaking past worn out valve guides and piston rings.

Other causes of smoky exhaust are brake fluid or automatic transmission fluid sucked through vacuum hoses to intake manifold from a faulty power brake booster or transmission modulator. Lastly white smoke indicates coolant leak.

Catch hold of the tailpipe of your car and shake it freely. If any mounds are loose, it may touch the body and rattle. Look over the exhaust system for loose bolts, loose mounding or cracks. Cracking around the muffler inlet or outlet is very common. Thus if any of these defects are noted in time it could save you from losing part of your exhaust system on a rough road.

Top      

Oil And Lubricants - Maintenance

The oil in your car's engine requires to be changed at intervals specified in your car's User Manual. So you should buy only oil of high quality and the type recommended for your car for the conditions under which it is driven.

It is interesting to note that motor oil does much more than lubricate engine parts and prevents destructive metal-to-metal contact. Special additives strengthen the lubricating film giving it the ability to withstand high pressures. Additives inhibit the formation of sludge, carbon and varnish deposits; they retard rust, which can result from the actions of acids and moisture that forms within the engine. Moreover, additives keep the oil from becoming too thick or too thin under extreme operating temperatures and control foaming of oil.

Nowadays synthetic oils are also available which last much longer before they need replacing.

How To Change Engine Oil :

Change the engine oil at intervals specified by the manufacturer of your car/ lubricating oil. Synthetic oil need not be changed as frequently. A clean funnel will serve to pour the oil. On cars with hard to reach filter caps, a funnel with a flexible neck may be needed.

Try to drain the oil when the engine is warm; the old oil will dry quickly and completely, and more of the contaminants that the oil holds in suspension will be removed. Be careful however of the engine parts that may be too hot. If the engine is cold, let the oil drain at least for 20-30 minutes before reinstalling the drain plug.

Changing the oil filter is part of the routine engine maintenance. Usually the oil filter is changed everytime you change the engine oil. But in any case at least twice a year it should be changed.

The Owner's Manual for your car will specify the type of filter needed. Purchase a reputable brand of filter and one that is designed for the service is essential.

Virtually all cans use a spin-on type of oil filter. When a new filter is installed make sure that the old filters' o-ring comes off with the filter and is not stuck to the filter housing. Clean off the matting surface of the filter housing and coat a new filter o-ring with clean oil. Then install the new filter following the instructions regarding tightening.

Even though many car makers allow long intervals between lubrication of suspension, steering systems, wheel bearings, transmission systems, etc. it is prudent to grease everything at least one a year.

Choose a chassis grease that contains molybdenum disulphide made by a reputable company. Most cars are equipped with nipple type grease fitting, but some have plug type fitting also. Always have some right angle nipples along with normal ones when going in for greasing of your car in a service station.

Top        

Radiator Fan

The function of the radiator fan is to help the radiator to dissipate the heat collected from the engine passages to the atmosphere and thereby bring down the temperature of the coolant/water that enters back into the engine via the water body pump. There are three types of fans used in modern cars. They are direct drive, clutch drive and electric drive.

The type used in your car depends upon the cooling requirements of the engine as well as the engine's location in relation to the radiator.

Most longitudinal engines have direct drive or clutch fans. Both types are directly located behind the radiator and bolted to the water pump pulley. If the car is equipped with air conditioning or has a large cooling system, it is probably fitted with a clutch fan. Both types can have either rigid or flexible fans. The electric fans are used in cars with transverse engines. Electric fans are bolted to the radiator shroud and powered by an electric motor. The motor is turned on and off by a thermostatic switch which is triggered by the coolant temperature.

To test the fan, hold it tightly and try moving it. If you detect any looseness, it can be due to bad water pump bearings and will require an inspection by a mechanic. Most new cars have electrically operated fans or plastic types coupled with a viscous hub. The viscous hub is a finned aluminum center that locks up the fan whenever the engine gets heated up. Therefore if you have a overheating problem in your car, you should check the viscous fan hub for leakage. If the silicone oil filled inside the hub leaks out, it results in reduced cooling power of the fan and thereby causes engine overheating. In electrically operated systems reasons for fan failure could be a blown fuse or a faulty radiator switch. In either case it is better to consult an expert.

Top        

Tyre Maintenance

When buying a car, you would have heard people say that the maintenance cost is very low or very high. But do you know that even you contribute in increasing the cost. A major chunk of money is wasted in tyres, i.e., money which could have been saved if only if you were more responsible. Anyway to be fair to you even ignorance is a culprit in this case. We at carstreet.com wish to dispel the ignorance and help you in your tyre maintenance.

THE BASIC STEPS TO BE TAKEN
The simplest and foremost step is to ensure that the air pressure matches the manufacturer recommended figure. Check the pressure at least once a week and do that in the mornings, when the car would not have run much. If a car is run for some time, then due to the heat that is built inside, the air pressure reading will not be right.

So what do we do about the tyre wear? A complication is that the wear will not be uniform. So rotation of the tyre is very important. Rotation should be done even to the spare tyre. So how is it done? It is to be between the same sides only. That is the left side rear tyre will find itself in the front in the same side. The left tyre should not be put to the right side. Another important thing is that after the rotation is done, the pressure should be corrected.

Everything starts and ends with tyre wear. Check the tyre wear and see whether it follows a set pattern. By knowing the pattern you can even rectify any other problem with the car. For example, an uneven wear may hint that something is wrong with suspension.

Also perform a regular check to see whether anything is stuck to the tyre. In addition to the usual stones that get stuck in the tyre, even a nail or a metal piece could be in the tyre.

Just performs these basic jobs and for once ignorance wont be bliss

Top