"An ounce of prevention is better than a pound of cure," runs an old adage, and nowhere is this truer than in the case of studiously maintaining a car or truck such that it continues to run day in and day out -- minus the headaches of a vehicle breakdown when it is most inconvenient (and expensive) to the owner.
And, contrary to what some believe, maintaining a vehicle in good working condition isn't that all hard, really. All it takes is a little common sense, a little vigilance for the "out-of-the-ordinary" signs or symptoms, and, perhaps, a little of the "do-it-yourself" (DIYs) spirit that each of us seem to possess (especially if - God forbid - one gets stranded in the middle of nowhere with no mechanic or gas station in sight !).
The tips I enumerate below are my own, culled from years of automotive experience (and some mis-adventures not worth mentioning!). If they don't work for you, sorry (!) but DO TELL ME, and I'll try to make amends somehow by referring you to some experts who can help you (guys like Mang Bitoy at: http://www.kotse.com/newkotse/read.php3#101). Fair 'nuf ? ... So, just click on any of the topics below...
Check the tire pressures (including the spare tire) every 2 weeks at a gas station equipped with an pre-setting air pressure gauge. When air-filling , do avoid dispensing with a tire gauge 'ala jeepney driver style' or because the gas attendant's too lazy to use one (most big stations also have a 'pencil-type' tire gauge somewhere, just ask). Or, buy your own tire gauge from an auto parts store and keep it handy in the glove compartment of your car (together with a flashlight, a must for night travel).
Tires are checked for pressure when cold, a tough act to follow when you get into a gas station from Manila's heavy traffic. Best way is to wait for the tires to cool off (when you're gassing up or in the john, whatever).
Before driving off from your garage, visually inspect tires for uneven or unusual wear - a sure sign of misalignment or mechanical looseness/wear, if not over-/under-infla- tion. After making certain the tires are properly inflated, you still notice a "banging" or whistling sound underneath, a "wandering" of the steering control, a wheel shimmy (uncont- rollable wiggle) at certain speeds - it's time to see your friendly underchassis mechanic/ wheel balancer guy.
Tire makers recommend a tire rotation every 10,000 kms. (either front-to-back pattern or cross-diagonal) so that the normal wear-and-tear is evenly distributed along the tire's rolling surface or tread, thereby prolonging its useful life. Tires with the thicker/better treads should be on the front (i.e.,steering) positions, for safety's sake.
When carrying a full-load of passengers plus luggage, one may add 5-7% more air pressure to the tires for the duration of the trip, but keep your speed below 70 KPH. Tires do become hot and automatically increase their pressures, so watch out. Better yet, don't overload !
Equally as bad as overinflated are underinflated tires, as heat damage can occur almost immediately on the sidewall ('soft') portion of the tire. Be alert for 'hard-steering' feel and uncharacteristic tilt of the vehicle (also, a loud thud when hitting a low hump or shallow pothole at slow drive). Unlike bloated tires, you cannot ignore a flat tire for long. For power-steering assist vehicles, the driver may not even notice the flat tire until he's "run it to destruc- tion" first (or when other motorists frantically signal you with vigorous hand-waving or finger-pointing, bless them!). The best way to avoid a flat is to do a "go-around-the-car" check prior to driving, particularly paying attention to the tires' condition. (Note: Somewhere in this Section I have included a 'Daily Vehicle Inspection Guidelist' for the car owner).
Lastly, don't mix tire sizes (and even brands, as much as possible) as it can affect your steering and therefore down-right dangerous. Well, you know the saying of the optimist driver : "Better you can't brake, as long as you can steer." Cheers !
What's an air-conditioner? An air-conditioner or "aircon" is that un-ubiquitous piece of equipment placed in your typical car, that keeps the occupants cool (relatively-speaking) even when it's sweltering hot outside. The cooling process starts when warm air inside the car's interior is drawn out by the evaporator unit's fan located under the dashboard and is circulated around its cooling coils filled with a refrigerant (known as 'freon' or R-12)*.
A while back, the driver switched on the air-con knob that electrically activated the air-con compressor(and the evaporator fan, too) found under the engine hood, to start 'compressing' the refrigerant within the system (initially a gas) . Freon has a special physical property in that it liquefies easily under pressure, in going out of the compressor and into the condenser (a series of metal narrow tubes with fins mounted in front of the vehicle, usually beside the car radiator).
(*Note: An ozone-friendly, non-CFC refrigerant known as 'R-134a' has now replaced freon R-12).
This change of state (from gas to liquid) of the compressed freon rapidly occuring within the condenser (while the latter is being cooled by a high-speed fan ) results in a drastic drop of temperature, enabling the 'cooled' freon to accumulate temporarily in a 'liquid tank' or receiver, also known as a filter-drier. There, the liquified freon is de-humidified (water removed) by a dessicant material, prior to entering the evaporator coils via an expansion valve. A blower fan keeps the interior air circulating around the cool coils of the evaporator, progressively transferring heat from the interior air to the freon, heating it once more. The heated freon once again turns into gas and enters the compressor to complete the cycle. The compressor, of course, is mechanically powered by the car's engine via a rubber belt, or aircon belt.
Finally, the cooled interior air gives up its water content at the evaporator pan, thereby accounting for that copious volume of water that otherwise has to be drained via a small hose going thru the floor of the car..
Conclusion: So, you see the car air-con is like yoiur ordinary household refrigerator in that the heat is removed from the vegetables and meat inside the ref (read: occupants inside the car) by freon-22 (freon-12 for cars) that has been cooled by compressor. The only difference is the ref's compressor is ran by electricity while the car compressor is powered by the car's engine. And, BTW. Freon is poisonous (contains chlorine) so don't make the mistake of inhaling some. And don't worry - it does not leak inside the car 'cuz it's under low pressure yet.
What could go wrong with my car air-conditioner?
There are generally 4 main things that could go wrong with the typical car air-con, namely:
1. No cooling from system; or,
2. Insufficient cooling from system; or,
3. Intermittent cooling; or,
4. Noisy system.
Although an expert air-con technician is ordinarily called for in cases like this, still it's instructive on the part of a car owner to at least be aware of the common causes of the air-con's failure to properly operate and save him/her a great deal of trouble. Knowing the causes could likewise "surprise" your mechanic into not taking advantage of your 'gullibility' and perhaps save you money. Let's take them one by one, shall we ?
No cooling
1) Blown fuse - easy to replace if you know where and how (locate the car's fuse box and read the label).
2) Broken or disconnected electrical wire - could be anywhere in the electrical connections of the switch, evaporator, compressor magnetic clutch, or the fuse box. However, the usual culprit is that wire connecting the compressor to the switch. Try a jumper connection from the battery to magnetic clutch. If the compressor "clicks," the problem lies with the compressor connection.
3) Broken or disconnected ground wire - the thermostat unit is equipped with a refrigerant pressure switch that's typically grounded; so's the blower switch, magnet clutch, aircon switch, and the condenser fan motor.
4) Magnet clutch coil or solenoid burned out or disconnected - see "2" above. Best fix: replace the coil (but not the compressor assembly, for goodness' sake !).
5) Non-operating thermostatic switch - either the contacts are worn out or the usual culprit is the sensing element which fails to open at a pre-determined temperature and de-activates the compressor. Replace rather than repair.
6) Blower motor disconnected or burned out - Immediately detected because you won't feel any air draft from the dashboard louvers. Have it checked out by a competent electrician/check the fuse box.
7) Ignition switch ground or relay burned out - Electrician's job.
8) Loose or broken drive belt - Open engine hood and inspect the compressor belt if loose, cut, or if it's still there ! Replace or tighten.
9) Compressor partially or completely frozen - Happens when you fail to check its lubrication (rarely happens, though).
10)Broken refrigerant line - resulting to leakage of freon out of system. One can detect the absence of refrigerant by running the system and observing the sightglass on top of the receiver tank. If you don't detect a liquid flow (or bubbles), chances are there's no more freon in the system. Replace line and recharge.
11)Leak in system - See "10" above. Check with your mechanic but don't always jump to this conclusion, as he wants you to believe, 'cuz there are other causes than just absence of freon.
12)Clogged receiver unit or expansion valve - Best checked by a manifold gauge, not by mechanic "feel." A clogged system manifests as an abnormally high reading of the "low" side of the aircon gauge.
13)Compressor
shaft seal leaking or damaged - Allows the escape of freon thru the shaft.
This condition may be detected by switching on the compressor
and observing
if there's a change in the engine RPM after the "click." (Note: The car tachometer,
if equipped, reads the engine speed or RPM). If the engine
RPM drops, then the compressor is okay. If not, system could be out of freon.
Insufficient cooling
1) Blower motor sluggish - The fan blades should be turning fast, otherwise it won't sufficiently cool the car interior. Hold up your palm to check this.
2) Compressor clutch slipping - Do you detect a "clicking" sound now and then ? Fix or replace coil.
3) Evaporator blower air discharge obstructed - Check the passages for dirt or crimped hoses.
4) Insufficient air circulation over evap. coils and fins - Due to dirt and algae growth (detectable by its rotten odor).
5) Insufficient refrigerant in system - A useful "do-it-yourself" prior to going to an aircon shop: Observe receiver tank sightglass for bubbles. If there are still bubbles after 5 minutes (instead of a solid flow), chances are freon's lacking. DO NOT OVERCHARGE FREON as this will damage your compressor.
6) Expansion valve unit malfunction - Clogged; use manifold gauge set to check.
7) Receiver clogged - use manifold gauge to check. Replace.
8) Air present in system/excessive moisture in system - High manifold gauge readings, plus bubbles in sightglass. Evacuate/vacuum system properly.
9) Improper adjustment of thermostat - Clutch cycling at high temp. readings. Adjust lower or replace thermostat.
Intermittent cooling
1) Compressor clutch slipping - See above.
2) Unit icing up - may be due to: excessive moisture in system, thermostat adjusted too low.
3) Thermostat non-functioning - when no change after many adjustments.
4) Clogged evaporator - Clean with soap or algae remover.
Noisy system
1) Loose or excessively worn drive belt - Screeching, or whining sound quite pronounced.
2) Compressor noise - Internal noise or clutch; also low oil level (open oil threaded cap & visually check).
3) Blower fan motor noise - Excessive wear of motor.
4) Idler pulley or bearing noise - Excessive wear detected by thumping or whistling sound.
5) Overcharged freon - Thumping sound/vibration along "high" side (compressor hot line/discharge hose, condenser); bubbles or cloudiness in sight-glass.
6) Low charge in system - See above; also, hissing sound at evaporator.
7)
Excessive moisture in system - See above; also expansion valve noisy.