This is how you change brake pads

Hardy Mutschler
Workshop tip
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N a, I don't want to kill, injure or induce anyone to do anything that could possibly put him in awkward situations. The subject of the “brake system” is therefore a particularly delicate matter.

To be very clear right at the beginning: The brake system on the car should protect the occupants and other road users and must always and under all circumstances one hundred percent function. The driver must be able to rely on the fact that he has a perfect brake in an emergency and that his vehicle will come to a standstill in an emergency. Hobby screwdrivers should therefore only work on the brake system if they really know what they are doing. Otherwise it is better to leave the job to a specialist workshop.

Since we are just at the preliminary speeches: Many thanks at this point to the people who have always given me feedback across all channels. A few comments on this. Of course, I screw without gloves - for two reasons: firstly, because there is an allergy to plasticizers (phenoxethanol) (makes ugly smallpox on the face), and secondly because it simply gives the better feeling 'without rubber'.

And yes, my stories are based on a fully equipped workshop as well as on knowledge that I gained on the road. A mixture of knowledge and improvisation, mostly with simple means and not always in compliance with all regulations.

Easily feasible for experienced screwdrivers

This issue is about changing wear parts of a run-of-the-mill disc brake system that is used in almost every vehicle (at least on the front axle). Drum brakes are often still installed on the rear axle (and on very old cars also on the front axle). In today's context, we only take care of this marginally.

The brake pad change for the disc brake system in question can be lifted with a standard jack plus fuse, common tools, copper, aluminum or ceramic paste and of course new material. You should change in good time and not just when a scraping noise indicates that the brake lining has now been completely worn off and metal is braking on metal. This is not only negligent and dangerous, it is also annoying because new brake discs are now due.

Leak? Acute troubleshooting!

Anyone who feels good in theright leg, recognizes when braking that the pressure point always comes a little later. Then it is time to check the brake pads. Another reason could be a leak in the brake system itself. This can be seen on the brake fluid reservoir: If you have to top up the fluid, you should look for the cause of the loss as quickly as possible.

Drum brake systems often have their weak point in the brake cylinders. Such damage can be seen fairly clearly in the swollen paint on the rims. Reason: The brake fluid is very aggressive. In the event of contact, it is best to clean with water, as this is ideal for neutralizing. Another problem can be leaks in brake hoses, lines or at the screw points.

In addition, wear damage to master brake cylinders is not uncommon. If liquid leaks, this can be recognized by paint stripping on the brake booster. Or it runs directly into the amplifier, then it is important to replace it. If you have to renew it, you should ask for an overhaul kit, it is usually much cheaper.

Change the brake fluid regularly

But even if there is no defect: Brake fluid is hygroscopic, so it attracts water. So the boiling point drops over the years - in the stupidest case the liquid starts to boil and the pressure drops. Means: Brakes no longer work or only works when you pump hard. To prevent this, the brake fluid should be renewed every two years.

In the case of frequent drivers, the brake pads are often worn out - it is therefore advisable to bleed and refresh the fluid as part of the brake pad renewal ensure safe stopping. And go: Jack up the box - and secure it with jack stands. Only in the desert can one make do with two tires under the sill. In any case, the car and the screwdriver must be secured against falling.

Do not let them hang

After the When dismantling the wheels, the brake piston can be carefully pressed back with a large flat-blade screwdriver. Under no circumstances should the sensitive cuff or the window be damaged with the tool. Loosen the brake calliper, but do not let it hang down so as not to strain the hose. This can be avoided with a wire or rubber that takes the load off by hanging it on the spring, for example.

The piston can be pushed back gently with large water pump pliers, also making sure that the piston sleeve is not damaged (cloth placed underneath). Use the wire brush to clean the treads on the brake caliper and apply paste to prevent it from squeaking and slipping well. If you only change the pads, you should file the treads a bit on the sides. This way they adapt to the target faster.

Pay attention to the tightening torques

The assembly allows few mistakes - if something is wrong, everything can no longer be put together. Important: Obtain manufacturer specifications for the torque of the retaining screws and please adhere to them ! Also of enormous importance after the change is pumping the brake pedal to the pressure point. Otherwise it goes straight through the wall when you brake for the first time. By resetting the piston, the pressure in the system is missing.

For bleeding a second person is required. He or she sits in the vehicle and evenly depresses the brake pedal until pressure is built up. The first person opens the vent valve when the pedal is depressed. The brake fluid should flow out until it is free of dirt and bubbles. It is suitable for collecting a transparent hose that is attached to a bottle. Only when the valve is closed can the second person release the brake pedal fth always starts at the brake furthest away from the brake fluid reservoir and ends at the next. Important: Always keep an eye on the container and refill with fresh liquid.

Block and disc customer - detect wear

Brake pads and discs are common wear parts. Depending on how and on which routes cars are moved (e.g. on the Nordschleife), the brake pads can be due after 10,000 to 20,000 kilometers. The discs last significantly longer. However, if you missed changing the pads, you have to change the brake discs completely unnecessarily, because these would then be damaged by the carrier of the block during braking. Depending on the model, you might have to pay 100 euros more than necessary in this case.

Check and appraise - this is how it works

▸ The wear on the front pads on the driver's side is usually checked first. This is where the greatest stress is due to the weight of the driver.

▸ The holes in the rims allow a good initial diagnosis to be made. However, you should definitely also check the inner linings for wear.

▸ Defective brake discs can be identified by deep grooves and an unevenly worn running surface. If in doubt, measure the thickness for wear according to the manufacturer's specifications.

▸ Shrill noises when braking indicate heavily to completely worn pads. That is life-threatening!


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