Mitsubishi Braking System Servicing and Repair
Mitsubishi Brakes can last for 50,000 to 100,000 miles depending on use and regular service. Modern braking systems use hydraulic links to transfer stopping power. The brake pedal is attached the Master Cylinder; a fluid filled hydraulic piston. Braking increases hydraulic brake fluid pressure. The hydraulic brake fluid is a non-compressible liquid so braking pressure is transferred via the brake pipes to the wheels and operates a slave cylinder piston that forces the brake pads against a brake drum or brake disc. The enforced contact between the brake pads and brake drum or brake disc increases friction to slow down or stop the vehicle.
- Inspect ABS warning light for correct operation
- Assess Mitsubishi brake pipes for corrosion and general condition
- Examine Mitsubishi brake pad movement and level of brake wear
- Inspect for deep scratches in case of imminent failure by scoring and system damage due to particle contamination
- Check auxiliary handbrake shoes where appropriate
- Check and adjust Mitsubishi handbrake travel
- Replace hydraulic brake fluid
- Inspect brake calliper condition
- Check brake calliper operation and inspect for leaking brake fluid
- Assess wheel cylinder condition
- Check wheel cylinder operation and Inspect for brake fluid leaking
- Check braking system for early signs of possible fatigue cracking
- Handbrake operation and handbrake travel
- Top up Mitsubishi Brake and clutch fluid levels if needed
- Hand brake linkages Check condition, clean and lubricate
- Brake drum condition
Mitsubishi Disc Brake and Drum Brake Systems
Drum Brakes are usually found on vehicle rear wheels. They are an older system than disc brakes and use two half moon shaped brake shoes that move outwards during use. They apply force against the inside of a brake drum. In contrast, the modern disc brakes have a pair of brake pads mounted either side of a brake disc. Braking pressure operates a slave cylinder. This forces a brake calliper to press the brake pads against the disc to apply the necessary stopping force.
Mitsubishi Power Assisted Braking
A vacuum or hydraulic system magnifies the force applied to the brake pedal during braking and helps slow or stop the vehicle. The brake pedal activates a valve to start the Power Assisted Breaking. An electronic sensing system checks the breaking power to create uniform breaking without the wheels locking and loss of control. If the engine stops or stalls suddenly then power assisted breaking will cease. If the hydraulic seals are intact then braking can be achieved by increasing the pressure on the foot-brake.
The Mitsubishi Engine Lubrication System
The primary system to protect the moving parts of your vehicle is the lubrication system. It may seem obvious but a motor vehicle is designed as a shell that uses engine power to move its contents from a starting point to a destination. This can be carried out efficiently using the minimum fuel energy or not. Imagine driving a car with rusty wheel bearings, the handbrake stuck and the brake pads seized onto the discs. What would happen? You would have to keep your foot on the accelerator, use loads of fuel and hope you got to your destination before the whole system tore itself apart. And where would all that excess fuel energy go? Heat The energy would be needed to overcome the friction caused by having solid surfaces in close contact. The oil is present to keep moving parts separate and reduce friction. It also contains anti-oxidants to help prevent corrosion. If the oil is too thin i.e. low viscosity it will not be able to fully separate the moving parts and be, literally, squeezed out of the gap by the bearing pressure. Similarly, if the oil is too thick i.e. high viscosity then the moving parts will be moving as if through treacle and need to use more energy to overcome the visco-elastic drag of the oil. Oil Change regularly with the correct grade oil to ensure maximum engine life for your Mitsubishi , acceleration and mileage. Oil viscosity will vary with temperature and not all moving parts are moving at the same speed or need the same viscosity oil. A compromise is necessary hence the need for Multigrade oils that can cope with a range of conditions. By using a reliable garage to change your oil you can be sure that while your vehicle is up on the lift, they will be visually checking the pipes, brakes, joints and suspension for any tell-tale signs of wear and tear.
Mitsubishi Oil Change Frequency
The old rule of thumb used to be every 3000 miles but many vehicle manufacturers indicate 5000 to 7000 miles. Initially, follow the manufacturers recommended oil change guidelines to ensure you validate your warranty.
Oil does not perform forever
Oil is composed of hundreds, if not thousands of individual chemicals and some of these will react chemically or break down with the extreme conditions they have to endure, changing the lubrication properties. Also, the anti-oxidants are sacrificed to protect your engine and will be used up first, removing the anti-corrosion properties of the oil. There are also moisture scavengers, detergents and acidity regulators that remove the effects water, particle, and fuel combustion residue contamination can have on performance and corrosion. Once they have absorbed the maximum amount of water and other contaminants they can handle then this also increases the risk of corrosion and failure. Modern synthetic oils can last longer because they have a more balanced molecular structure and fewer natural impurities that increase oil breakdown compared to the cheaper refined oils.
Mitsubishi Oil Change Recommendation
Keep a small amount of the oil used to lubricate your vehicle in a sealed container. When you check your dipstick for oil level compare the lubricity or feel of the oil with your reference sample of fresh oil. If the oil in your engine seems thin in comparison then it may be time to replace it. The cost of a new oil filter and oil change is negligible compare to the cost of an Engine Rebuild. Regular preventative maintenance and routine servicing work outs cheaper in the long run.
Oil Pressure Gauge or Mitsubishi Oil Light Warning
If you have an Mitsubishi oil-light, ensure it lights before you start the car and extinguishes immediately after. If not, you may have a faulty connection or sensor. Oil pressure gauges normally start at zero rising to normal shortly after start-up. If your oil light is on or the gauge reads zero while the engine is running then chances are that the engine is running without lubrication and should be switched off and checked immediately or it will overheat and seize. Ensure you don't have an oil leak. Check to confirm if the dipstick measurement is low then top-up as normal and make sure the new level does not drop rapidly after a few minutes. If the oil gauge reads normal and the oil-light goes off then this may be your problem. If you feel confident to drive and all is well, monitor your dipstick measurements and make sure you aren't losing oil before assuming the all-clear.
The Cooling System - Mitsubishi Radiator Failure and Repair
The cooling system is designed to prevent overheating by transferring and dissipating the heat generated by fuel combustion in the engine. This is achieved by creating and circulating a water jacket around cylinders and head, passing the excess heat from engine to water and finally removing it by passing a current of air over a huge surface area created by a set of thin metal fins of a radiator (Incidentally the heat is transferred mainly by convection not radiation) Radiators are usually filled with a mixture of water and a glycol-based anti-freeze. Most cooling system failures can be attributed to poor radiator maintenance and could be prevented with regular maintenance and occasional professional inspection.
Common Mitsubishi radiator problems
Leaking fittings or seams Parts age, corrode and wear with the normal regular daily use of your Mitsubishi so the polymer or rubber hoses, hose clamps, bonded seams, and secondary system fittings such as an automatic transmission oil cooler will eventually fail. Check for heavily corroded or rusted clamps, for splitting or leaking seams where the cores join the tanks, and nipped, split or brittle and cracking hoses.
Radiator Fin Corrosion Damage
The thin metal radiator fins are continuously exposed to road salt, water and dirt. At the very least; dirt build up will dramatically reduce the cooling efficiency of your radiator by forming an insulating film on the fins reducing air flow and heat transfer. Also, the particles of dirt and salt can form corrosion points by a process of electrolysis where a microscopic battery forms. Once initiated this type of corrosion can eat rapidly through the radiator wall and cause pin-hole leaking. Mechanical damage caused by bending the radiator fins, stone impact etc can also initiate micro-cracks in the metal surface. Salt, water and the presence of any dis-similar metal or particle can then cause rapid corrosion and crack propagation.
Radiator Bond Failure
Radiator cores can be bonded to the primary tank using solder or epoxy and create common points of corrosion or stress failure in radiators. The radiator undergoes extremes of temperature every time the vehicle is used. This causes rapid expansion and contraction of the radiator material and will tend to fail at any weak point where the expansion-contraction forces are magnified.
Electrolysis Failure
Dirt in the radiator fluid or the use of water high in dissolved minerals - especially transition metals can eventually cause scaling and sediment build-up inside the radiator. This build up occurs by electrolysis where the radiator forms a giant wet-cell battery. Specially designed chemical radiator cleaners can be used to remove this build-up but cannot replace the metal removed from the radiator by electrolysis.
Tank Cracking
Sometimes caused by corrosion and sometimes Stress-Fatigue cracking. Some modern radiators have removable tanks that can be replaced.
Radiator Fan damage When there is insufficient air-flow to remove the excess heat a thermostat turns on an electric fan to increase airflow and cool the radiator. A loose or damaged fan can hit against the radiator when the car goes over a bump or changes direction.
Mitsubishi Thermostat Failure When the engine is idling and the vehicle is stationery or in slow moving traffic there is insufficient air flow to keep the engine cool. Thermostat Failure will prevent the cooling fan from being engaged and will lead to overheating. Thermostat or Fan Failure can be easily checked by letting the car warm up and stand for a few minutes it should be possible to hear and see the fan being engaged. There is also a thermostat controlling the flow of cooling fluid to the engine so that the engine can reach optimal running temperature. If this thermostat fails to let coolant flow correctly it can lead to engine overheating.
Modern ignition systems
Mechanically timed ignition
Until recently, most four-stroke engines used a mechanically timed electrical ignition system. The heart of this mechanically timed ignition system is the distributor, containing a rotating cam synchronised to the engine, a set of breaker points, a condenser, a rotor and a distributor cap. The distributor is connected to the ignition coil and the spark plugs via a highly insulated ignition wiring system. The electrical power source is the ubiquitous lead-acid battery that is charged while the engine is running by a dynamo or alternator. The rotating engine operates contact breaker points interrupting or modulating current flow to an induction or ignition coil. The ignition coil consists of the primary and secondary windings of a transformer on a common magnetic core. They form 2 separate wiring circuits and are joined together at common point that connects to the battery via a current limiting resistor. The primary coil is also connected to the points within the distributor. The secondary is connected to the spark plugs through the distributor cap and rotor. The rotating cam controls the opening and closing of the breaker points and the Primary is fed with current when the breaker points close. This induces a magnetic field to form. As the engine turns it reaches the top of its compression cycle. This is synchronised to be the point when the breaker opens, switching off the Primary circuit. The magnetic field collapses and generates a high voltage in the coil's secondary windings. A condenser capacitor holds the excess energy until it can be released causing a spark across the gap in a spark plug. A rotor, within the distributor cap, sequentially connects the coil's secondary windings to one of the engine's spark plugs.
Mitsubishi Electronic ignition
The breaker points are subject to mechanical wear through continuous rubbing against the cam during each open-close cycle. Oxidation and burning of the contact surfaces occurs with sparking across the gap. Compensating for wear, the system needs regular adjustment to maintain optimal firing performance. Electronic ignition (EI) solves these problems where the breaker points are replaced by a rotor angle sensor such as a Hall effect magnetic field sensor that triggers a switching device such as a thyristor, for shunting a large flow of current through the coil. The distributor and spark plugs remain the same as the mechanical system. The lack of moving and rubbing parts compared with the mechanical system leads to greater reliability and longer service intervals. Older cars could be retrofitted with an EI system in place of the mechanical one. Sometimes, a modern distributor will fit the older engine with no other modifications.
Engine management Systems - Mitsubishi EMS
In a modern Mitsubishi Engine Management System, electronics control virtually everything - fuel delivery, ignition timing and the firing order. The Primary sensors on the system are engine angle checking Crank Position or Top Dead Center TDC, airflow into the engine and accelerator position for fuel demand. The modern Mitsubishi electronic circuitry creates a mini-computer or Electronic Control Unit (ECU) that determines which Mitsubishi cylinder needs fuel, how much, opens the appropriate injector valve, delivers the fuel, causes a fuel ignition spark at just the right moment to burn it. Some EMS designs still use the coil, distributor and spark plug system. Now its is possible to use special spark plugs containing their own coil for Direct Ignition. Modern EMS systems even monitor other important engine efficiency parameters such as temperature, the level of free oxygen in the exhaust. This allows greater control of the engine to minimise un-burnt or partially combusted fuel and other noxious gases - the so-called SOx NOx Gases, leading to much cleaner and more fuel-efficient engines.