Brake inspection

Brake Inspection

When checked all four wheels for brake inspection, it was disc brake with callipers, the front were non vented the back was vented disc type.
The Brake pads had enough treat left on it but the rear brakes were worn unevenly and the inside of the disc had a few chips in it.
Carrier plates need replacing or servicing

30mins to 1 hour is enough to do a full brake service, maybe 90mins if you are new to it.

3 Different drum brakes

Servo:  Its not connected at the bottom. The brake servo unit intensifies the force of the driver’s foot on the brake pedal. If the driver starts braking, the connecting rod moves left, pressing the seal of the double valve against the valve seat, thereby closing the connection between the two chambers

Simplex:  the Simplex drum brake has the trailing shoe to the right and the leading shoe to the left. The shoe is called leading, if a certain point of the rotating drum passes the spreading mechanism (in this case the wheel cylinder) before passing the anchor-pin side. This creates a wedging effect, which produces a relatively large braking force in spite of only little pressure on the brake (self enhancement). With the trailing shoe the effect is the opposite.

Duplex: The Duplex brake has two leading shoes in the roll direction (i.e. on the left). Reversing however, causes these to wear.

Brake Pads, Disc and Piston

Brake pads should be replaced every now and then, the minimum your pad can be is 1mm, so have to keep a look out for that. You don't want it to completely ware off and damage your brake disc.

BRAKE DISC
The brake disc is the disc component of a disc brake against which the brake pads are applied. The weight and power of the vehicle determines the need for ventilated discs, The "ventilated" disc design helps to disperse the generated heat for faster cooling. Discs are usually damaged in one of four ways, scarring, cracking, warping or excessive rusting.

RUN OUT and THICKNESS OF DISC
The Run out is measured using a DTI gauge, once its installed right, spin the disc and measure the maximum and minimum run out, if its out of the manufactures range then it can be machined.

Thickness of disc can be measured by using a micro meter, you need to measure the inner thickness and the outer thickness, and if the difference is too much then it can be grinded down. 

SLIDES and THE PISTON

The movement of the pistons is controlled by a hydraulic system. When hydraulic pressure is applied by pressing the brake pedal, the piston is pushed forward to press the inner pad against the rotor while the housing is pushed in the opposite direction to press the outer pad against the rotor, hence generating a hydraulic clamp around the rotor. For the fixed (non-floating) caliper type of disc brake system, each piston presses the brake pad against its respective side of the brake rubbing surface, as shown in Figure 

THE BRAKING SYSTEM

GENERAL PRINCIPLE

1. Kinetic to heat energy

2. Force of brake pedal

3. Forces the push rod in the brake booster which in turn forces the primary piston in the master cylinder forward, the fluid pressure pushes the secondary piston

4. The brake pipes carry fluid pressure to proportioning valve then to the brake callipers

5. the piston forces the brake pad against the disc rotor  

6. The friction reduces the rotor speed.

7. The wheel being attached to the rotor is therefore slowed down.

Most modern cars have disc brakes on the front wheels, and some have disc brakes on all four wheels. This is the part of the brake system that does the actual work of stopping the car.the most common type of disc brake on modern cars is the single-piston floating calliper.

 

How disc brakes work!   VIDEO

How to Bleed brakes!

1. Clean out reservoir
2. Top up with new fluid
3. Select DOT
4. Open bleeder nipple
5. Put block under brake pedals
6. Pump 6 times, hold down
7. Open nipple and close again
8. Pump 6 times and hold down
9. Open nipple and close again

Why do we bleed?

To replace old fluid, or if you are replacing a brake park, if there is air in there you have to bleed it.

Drum Brakes

Brake shoes, with linings attached, are situated inside brake drums. These drums revolve with the wheel. When pressure is applied to the brake pedal, hydraulic fluid in the braking system forces the brake shoes outward until the linings come into contact with the inside of the drum and force it to stop.

Disc Brakes

These operate on a similar principle, except that the brake consists of a stationary caliper, with a disc revolving with the wheel. When the pedal is pressed down, hydraulic pressure forces pads in the caliper to clamp on the disc, much like the operation of a bicycle brake. Most late model cars have disc brakes or a combination of front disc and rear drum brakes.

Brakes are sensitive to heat, water and moisture, and the pads and linings wear every time you put your foot on the brake pedal.

Transmissin and Drivelines

                                                   CLUTCH

A clutch is two metal plates in the engine. When you press the clutch pedal down the plates come apart separating the engine from the drive wheels allowing you to change gear. Bringing the pedal back up re-engages the plates which in turn connect the engine to the drive wheels. As your car engine is constantly running, a clutch is needed to separate the engine from the drive wheels when you stop the car. Pressing the clutch down just before you stop does just this, otherwise the car would stall.

 

 

 

GEARBOX

Front Wheel gearbox

Rear Wheel gearbox 

Automatic Gearbox

Transaxle Gearbox

In the automotive field, a transaxle is a major mechanical component that combines the functionality of the transmission, the differential, and associated components of the driven axle into one integrated assembly.

Synchroniser: it is a toothed ring between the gears of a manual transmission that helps bring the 2 sets of gears to the same speed so they mesh easily during a shift.

Circlip: A circlip (a combination of 'circle' and 'clip', and pronounced thus), also known as a C-Clip, snap ring or Jesus clip, is a type of fastener consisting of a semi-flexible metal ring with open ends which can be snapped into place, into a machined groove on a dowel pin or other part to permit rotation but to prevent lateral movement. There are two basic types: internal and external, referring to whether they are fitted into a bore or over a shaft. Circlips are often used to secure pinned connections.

Bell housing: is a colloquial/slang term for the portion of the transmission that covers the flywheel and the clutch or torque converter of the transmission on vehicles powered by internal combustion engines.

Torque converter: The torque converter normally takes the place of a mechanical clutch in a vehicle with an automatic transmission, allowing the load to be separated from the power source. It is usually located between the engine's flex plate and the transmission.

Fuel and Fuel system

                                   Fuel and fuel system

INJECTORS

To test your injectors, you have different ways, u can use noid light, multi meter or use a screw driver to hear the injectors moving or spraying.

The primary difference between carburetors and fuel injection is that fuel injection atomizes the fuel by forcibly pumping it through a small nozzle under high pressure, while a carburetor relies on suction created by intake air rushing through to draw the fuel into the airstream.

Reflection

When using the Noid light, you need to disconnect the sensor wire and plug the noid light in, if it keeps flashing then its defiantly working. And need to check the sensor wire, it should be around 5v. Injectors also need to spray equally, if its blocked up then you need to replace it.

Testing Emissions

Catalytic converter

The catalytic converter is a device placed in the exhaust pipe, which converts hydrocarbons, carbon monoxide, and NO_x into less harmful gases by using a combination of platinum, palladium and rhodium as catalyst.

Exhaust Gas Recirculation

Exhaust neither burns nor supports combustion, so it dilutes the air/fuel charge to reduce peak combustion chamber temperatures. This, in turn, reduces the formation of Nitro oxide

Fuel Pump

A fuel pump is a frequently (but not always) essential component on a car or other internal combustion engine device. Many engines (older motorcycle engines in particular) do not require any fuel pump at all, requiring only gravity to feed fuel from the fuel tank through a line or hose to the engine. But in non-gravity feed designs, fuel has to be pumped from the fuel tank to the engine and delivered under low pressure to the carburetor or under high pressure to the fuel injection system. Often, carbureted engines use low pressure mechanical pumps that are mounted outside the fuel tank, whereas fuel injected engines often use electric fuel pumps that are mounted inside the fuel tank (and some fuel injected engines have two fuel pumps: one low pressure/high volume supply pump in the tank and one high pressure/low volume pump on or near the engine).

Diesel Glow Plug

Glow plugs can be tested by, taking the glow plug out and putting 12volts on it. And if it is working well it should get bright red within 10 seconds.

The engine is unable to start, because it cannot generate and maintain enough heat for the fuel to ignite. For that reason indirect injected diesel engines are manufactured with glow-plugs in each pre chamber, and direct injected diesel engines are manufactured with glow-plugs in each combustion chamber to heat up the air.

Fuel Pressure regulator

SENSORS

Map:  The manifold absolute pressure sensor (MAP sensor) is one of the sensors used in an internal combustion engines electronic control system. Engines that use a MAP sensor are typically fuel injected. The manifold absolute pressure sensor provides instantaneous manifold pressure information to the engine's electronic control unit (ECU).

Maf: A mass air flow sensor is used to find out the mass flow rate of air entering a fuel-injected internal combustion engine. The air mass information is necessary for the engine control unit (ECU) to balance and deliver the correct fuel mass to the engine

Tps: A throttle position sensor (TPS) is a sensor used to monitor the position of the throttle in an internal combustion engine. The sensor is usually located on the butterfly spindle so that it can directly monitor the position of the throttle

Bleeding Diesel Engine

Here are the steps to take in bleeding air from a diesel fuel system:

1. Turn off fuel valve.

2. Clean outside of filter housing.

3. Install new filter element and new gaskets. A little oil on the gasket will aid a tight

seal.

4. I'd suggest that you fill a spin-on filter with clean fuel before installation.

5. Open the bleed plug on the filter closest to the fuel tank.

6. Open fuel supply valve so that the fuel is available to the filter and pump.

7. Most all equipment has a hand priming pump lever to pump fuel through the system

and replace trapped air. (Check operator's manual.) Pump several times until full

flow, without air bubbles, escapes from the bleed plug holes.

8. You may need to bleed filters, fuel pump and lines to the injectors.

9. Close bleed plugs after all air is removed from the fuel tank, filters, settlement bulb,

and fuel pump (only one at a time working through all bleed screws beginning closest

to tank and ending at nozzles if necessary).

10. Try the engine; if it doesn't start or runs poorly, you may have to bleed the injection

line.

11. Loosen injection lines at the injectors about one turn. The use of two wrenches will

prevent the binding or twisting of the steel lines. Usually, it is enough to bleed just half

of the lines at a time.

12. Crank the engine until all air is forced out and fuel is present.

13. Engine will start to pop on one or two cylinders.

14. Tighten the injector lock nut one at a time to tell by sound which cylinders are firing

properly.

15. Run the engine until it runs smoothly. This will bleed the other injectors.

Valve Clearance

Valve clearance is the distance or gap between the cam and the top of the valve.  Because the engine has a rocker arm between the cam and valve, we measure this clearance as the distance between the cam and the rocker arm pad. We adjust the clearance by turning a set screw located at the end of the rocker arm.  The bottom of this screw effectively rests on top of the valve, so turning the screw clockwise moves the rocker arm up towards the cam (less clearance), and falls away (more clearance) if we turn the screw counter clockwise.We need to occasionally check and adjust valve clearance because the these components wear slightly with use and the clearance may fall out of the specified range resulting in extra wear (not enough clearance) or lost performance and noisy engine (too much clearance). 

cylinder block

         PISTONS

This picture shows the basic function of the pistons. Basically when the air and fuel mixture is compressed
it ignites and creates a spark for the spark plug. the crank shaft makes the pistons move up and down and also in a order.

CRANKSHAFT

 Receives oscillating motion from connecting rod and gives a rotary motion to the main shaft.It also drives the camshaft which actuate the valves of the engine.

 Cam Shaft

It takes driving force from crankshaft through gear train or chain and operates the inlet valve as well as exhaust valve with the help of cam followers, push rod and rocker arms.

Inlet Valve & Exhaust Valve

Inlet valve allow the fresh charge of air-fuel mixture to enter the cylinder bore. Exhaust valve permits the burnt gases to escape from the cylinder bore at proper timing.

Carburettor

It converts petrol in fine spray and mixes with air in proper ratio as per requirement of the engine.