Trucks travel the highways transporting goods and other merchandise. In order for this large vehicle to stop safely, it is of great essence that the brakes function properly. The most common brake system found in this large vehicle is the compressed air brake system. Let us take a look at a simple truck repair, in this case, replacing a brake on a huge truck at home.
The replacement of drum brakes is not that difficult however, it requires special tools and of course, caution. As a result, you will save on the hefty auto mechanic bills. This video describes to you the general process, but it will still be advisable for you to consult the manual for your own vehicle’s parts. However, if you are a hands on person who likes to get their hands dirty or save on cost you can actually perform a home truck repair.
Truck Repair At Home
The work will involve getting into contact with finely-ground brake dust or asbestos dust, and having it in your breathing airway can be extremely hazardous to your health. For this, you will have to acquire a mask that is designed for the job of filtering asbestos. If there are kids and pets are around, you will have to send them away; you do not want them anywhere near this project, for their own safety.
First, you will have to remove the hubcap and loosen the lug nuts with your spanner. Before moving on with the process, you will have to block the front wheel with wheel chocks. Complete the removal of the nuts and finish off with the tire. This is a basic concept in truck repair.
The hub of the wheel then requires spraying with a penetrating oil, for instance the PB blaster. There are other types of oil which you should be cautioned of that are not penetrating.
You can then grab the brake drum by the edges and pull it off. Wiggling it can assist you to remove. It may also be important to back off the brake adjuster to remove the drum. This you can achieve through the brake adjustment hole in the drum or on the backing plate using a brake adjuster tool to turn the adjuster to loosen the brakes enough to remove the drum.
You should reface or replace if it is scored. The drum brakes have a bunch of springs and levers for the self-adjuster and parking brake. Using a bolt joint clamp can be hit to remove the bolt, alternatively, heat can be applied on the bolt to loosen it which tends to work most of the time. Knocking out the bolt with an air hammer can leave the covering of the bolt still intact on the joint, but this can be removed using an air chisel. The chisel tip is specifically designed with its sharp spear-like edge to remove any bolt residuals. The break drum is fastened to the wheel hub.
The inside of the drum should always be smooth, not rough or have any foreign material.
The brake lining always forced to move or pivot upon applying the brakes. There should be adequate friction to be able to stop the tires from moving.
The brake lining is connected to a metal surface known as the shoe. The lining and shoe are fastened together by rivets. There are always two brake shoes at each drum. The brake shoes and lining are held in place by the spider cast. This particular casting should not be loose or cracked. One end of the break shoe is held by anchor pins which provide a pivot for the brake shoe when brakes are applied.
The anchor pins can at times rust. This is not good as it can freeze the brake shoe. Return springs are also important as they facilitate the application of brakes. These return springs are highly stressed and can fail due to corrosion.
Get the roller out, in normal cases, the brakes are put on over because most of the time they are usually rusted.
Important Tips To Note During Truck Repair
Although this process tends to leave a mess where the bolt was use a file to smoothen it up. Then, new rollers are put in place of the old one. These are easy to place due to the presence of a split on one side that allows them to be placed without much effort.
The drums are then hooked up together after placing a new pin in the 4-inch hole. The rollers are attached to the drums as well before placing it back on the wheel area. The brake drum is cleaned to remove the greasy oil that is present. It is then inserted to its position, followed by tightening of the brake fuse before placing the tire on.
The whole brake mechanism should be placed in a container and sprayed with a brake cleaner. If you do this in a container, it will help keep the dust from becoming to airborne. There are several key things you need to ensure are done. These are;
- Make sure the brake shoes are the same width, then dismantle the brake.
- Remove the shoe return springs.
- Detach the parking brake lever.
- Hold the shoe retaining pin from the back and remove the retainer springs.
- Spread the shoes apart from the top and disengage the shoes from the wheel cylinder pins.
- Remove both shoes and the self-adjuster as one unit.
- Lay the old shoes on the ground next to the new ones.
At times, the front and back shoes are different, depending on the vehicle. The shoe with the shorter strip of lining usually goes towards the front. One should be very keen on this during truck repair. You must be keen to tip the tops of the shoes inward to loosen the tension on the self-adjuster spring.
An inspection should be done, and cleaning of all the brake parts to be reused on the vehicle and check for signs of damage or wear and replacement to be made where needed. It is normally recommended that replacement of all the springs with a new set should be done when repairing a truck. This is because the springs tend to develop a lot of tension and rust. Then, the adjuster should be unscrewed, cleaned and lubed with an anti-seize.
When you remove the spring, you should immediately hook it onto the new shoes exactly as you removed it, to retain its helical power and tension. Again, inspect the brake wheel cylinder for any signs of leakage, or cracks and replace if needed. In the case of rebuilding a new break, the following steps should be taken:
- The brake backing plates should always be cleaned and lubed.
- Always screw the self-adjuster back in, one of the sides will be a left-hand thread.
- Ensure you place the self-adjuster on the new shoes and spread the tops apart to tighten the spring, maintain its tension.
- Make sure you put the shoes back in place and slip the retaining pins through the right holes,
- Install the shoe retainer springs.
- Attach the brake shoes to the wheel cylinder pins.
- Make a reattachment of the parking brake lever.
- Install the return springs.
- And finally, using a brake adjustment sizing tool, adjust the brakes to fit the brake drum.
Truck repair can be done with the right tools. Knowing the various parts of your truck is very important. When it comes to an emergency, and your truck needs repair, then the knowledge you acquire could be put to good use and perhaps save time and money as well.
Important To Note!
If at all you notice a bleed off, you should rebuild or get a new master cylinder.
Asbestos is harmful, it is a natural fire retardant and can handle heat quite well.
Always bleed the brakes until the fluid can run clear and you can no longer observe air bubbles, but with the engine off.
The above listed cautions are some of the truck repair notes that are crucial during the repair operation.