how to: front brake pad replacement

[noss]

how to change your brake pads in the u12
[author]tas.rx

[noss]

Replacing the front brake pads on your U12 Pintara

Please note…
If you are not confident in doing this, SIMPLY DON’T!  ANY FAULTS IN YOUR BRAKING SYSTEM CAN BE FATAL.  The money you save by replacing the pads yourself is not worth risking yours or someone else's life for.  If you don't have a very good mechanical aptitude and lack basic skills I suggest you leave this job to the proffessionals.

IF YOU THINK YOU MAY HAVE MADE A MISTAKE WHILE REPLACING THE PADS, HAVE A QUALIFIED MECHANIC LOOK OVER THE BRAKES TO MAKE SURE THEY ARE SAFE, AND IF NOT RECTIFY THE PROBLEM.


What you Need:
•   New Front brake pads
•   Brake Fluid
         - Make sure it’s Dot 4
•   10mm ring spanner for brake bleed nipple
•   14mm ring spanner or socket for caliper bolts
•   Trolley jack or similar
•   Jack stands
•   Wheel chocks (or bricks) for back wheels
•   Torque wrench + 14mm socket
•   Clean rags
•   G- Clamp
•   Small block of wood for between G- Clamp and piston
•   Container for brake fluid
•   Thin clear tubing suitable for bleeding brakes
        -   You can buy special one man brake bleeders from spare parts stores/Big W for around $10, they make brake bleeding easy                    when you’re on your own.



1.   Place your wheel chocks/bricks/wood blocks under the back wheels
2.   Release the tension from the wheel nuts
3.   Raise the car with your jack
4.   Place jack stands under the car in the positions shown below
5.   Remove the jack so that the car is resting on the jack stands
6.   Make sure the car is stable and the jack stands are correctly placed


7.   Remove both front wheels

8.   Remove the bottom caliper pin bolt and release the tension from the top pin bolt

9.   Swing the cylinder body upwards

10.   Remove old pads and inner and outer shims






You now need to retract the caliper piston back into the caliper body.  To do this you need a G –Clamp and a block of wood big enough to cover the piston face, but small enough not to touch on the caliper body. I was lucky enough to have a round piece of wood lying around that was the perfect size.  You can make one of these yourself by cutting a 60mm hole in a block of wood with a hole saw, however it is not necessary.

11.   Place your clamp and wood in the caliper body as pictured below

12.   Force the piston with the clamp into the cylinder until it is even with the rest of the caliper body.
13.   Remove clamp and wood.

14.   Take the the inner and outer shims off the old pads and place them onto the new pads

-   Check the shims for damage/bends if there is any, replace them with new shims.  Mine were fine, apart from cosmetic damage, which isn’t an issue.
15.   Place the new pads with shims into the caliper

16.   Swing the caliper body back into position
17.   Refit the lower caliper pin bolt
18.   Tension the upper and lower caliper pin bolts with a torque wrench to 31 and 41 Nm.

Bleeding/Replacing the brake fluid

It is not totally necessary to bleed the brakes after this procedure.  However if you suspect that there is air in the sytem you need to bleed them. Also, you should completely flush and bleed the brake system at least every two years.  If the fluid is a dark colour and due for replacement soon replace it and bleed the brakes while you are working on them.

Bleeding the hydraulic system should only be necessary when some portion of the hydraulic system has been disconnected or fluid has been drained, allowing air to enter the system.

There are four points in the system where bleeder valves are installed, one on each front caliper and one on each rear wheel cylinder or rear caliper.

1.    Fill the fluid reservoir with clean hydraulic brake fluid and maintain at least one third full throughout the entire operation.
2     Attach a clear hose to the bleeder valve on the left rear caliper and immerse the other end of the hose in a small amount of clean brake fluid contained in a clean glass jar held higher than the bleeder valve.

NOTE:  If you choose to use a one man brake bleeding kit just attach the open end of the tubing to the bleeder valve, fit the safety strap over the bleeder valve (to stop the tube coming off) let the one way valve hang and place a tray under neath the brakes to catch any brake fluid.

3.    Unscrew the bleeder valve one complete turn.

4.    Have an assistant depress the brake pedal slowly to the full extent of its travel.  Close the bleeder valve and allow the brake pedal to return without assistance. 

NOTE:  If using a one man brake bleeding kit, pump the brake pedal in and out until there are no air bubbles in the fluid in the tubing, pump the pedal a couple more times just to be sure and then close the bleeder valve and remove the tubing. (The one way valve on the end of the tube will not let any air in to the system it will only let air and fluid out)

5.   Repeat items 3 and 4 until a constant stream of fluid, without any air bubbles, is being discharged into the glass jar, hold the brake pedal down and tighten the bleeder valve.

NOTE:  If changing the brake fluid, continue bleeding the system until clean new fluid flows from the bleeder hose.  Do not allow the fluid level in the reservoir to fall below one third full level at any time during the operation or air will enter the system and a fresh start will have to be made.  Always use new brake fluid when topping up the reservoir.

6.   When the left rear brake is bled correctly perform the operation on the right front, right rear and left front brake in that order.
7.   Replenish the reservoir with the specified brake fluid to the indicated level and install the reservoir cap.


Bedding in your new pads
Once you have installed your new pads and are sure everything is fitted correctly, you need to bed the new pads in.  Bedding them in will help burn off any residue from the manufacturing process and set the pads into the caliper properly.  This will maximise the performance of your new pads.

Here are instructions for bedding in brake pads, they are off the side of the Bendix brake pad box, but the basic rules apply to most pads, you will most likely get bedding in instructions with your new brake pads. 

1.   Accelerate vehicle to 50km/h
2.   Apply brakes using moderate to firm pedal effort reducing speed to 5km/h
3.   Drive 100m-200m accelerating to 50km/h
4.   Repeat steps 1 to 3 between 8-10 times

Following the above procedure will optimise the performance of your new brake pads and ensure maximum pad life and braking performance.

WARNING

-   DO NOT EXCEED 50km/h FOR BEDDING IN PROCEDURE
-   NEVER DRIVE VEHICLE WITH BRAKES CONTINUALLY APPLIED    DURING THE BEDDING IN PROCEDURE
        These actions will cause excessive heat to be generated, resins to be burnt and loss of braking efficiency.

Not all pads use the same mix of fibres and other ingredients, so there may be a specific bedding in procedure for different pads.  If you get instructions with your pads (either on or in the box)  go by those instructions.

[KatieSmurf]

*giggles*

All I could see from the front page was re: changing bra...
And I thought to myself 'That should be a tech article, then more guys would figure out how to get them off chicks ' Couldn't help but wonder where noss got enough experience to know how You sly dog you

I'm in a silly mood, can you tell?

[MAG86]

wtf???

I CONT SEE ANY PICS WHATSOEVER!
I need to do this tomorrow, can anyone help me get the pics loaded???

[Jtas]

Not sure what's happened to the pictures.  I know longer have them on my computer, thinking that they were on the antrx server I got rid of them.


but, given the detailed instructions, if you can't do the job without pictures you probably shouldn't be doing it.

[Budgie]

Indeed, its pretty bloody easy Mag.