In road traffic, brakes are critical to your safety and the safety of others

That's why regularly checking your brake system is your best life insurance. Don't be afraid to work to remove the wheels and check the condition of the brake pads.

Caring for the brake system is not such a scary thing.

And most types of work with brakes require no more effort than removing a wing or shock absorber.

However, only take on the task if you are quite confident in your abilities.

- Cause of malfunction and method of elimination

Increased brake pedal travel:

Presence of air in the hydraulic drive system

Bleed the system, article - "Replacing brake fluid and bleeding the brake system of a Gazelle car"

- The thrust ring of the rear wheel cylinder piston has lost its elasticity and, under the action of the tension spring of the brake pads, together with the piston, moves inside the cylinder

Replace the wheel cylinder assembly

- Violation of the tightness of the brake system (fluid leakage)

Locate the location of the fluid leak and replace the parts affecting the leak.

If there is a leak in the pipeline connections, tighten the connections or replace the sealing gaskets

- Increased clearance between the head of the vacuum booster adjusting bolt and the master cylinder piston

The brake pedal moves down slowly with the force on it constant and the parking brake applied:

- Damage to the cuff

Replace the damaged cuff

The brake mechanisms of all wheels or axles are not fully released (the suspended wheels rotate tightly):

  • - Lack of clearance between the head of the vacuum booster adjusting bolt and the master cylinder piston
  • - Incomplete return of the brake pedal after braking due to incorrect installation of the brake light switch

Set a gap (8+1) mm between the plastic tip of the brake light switch and the pedal stop

- Clogging of the compensation holes of the main brake cylinder or blocking of the compensation holes with the edges of the cuffs

Remove the master cylinder reservoir and connecting sleeves.

Clean the expansion holes with soft wire 0.6 mm in diameter.

If the wire rests against the cuff, then it is necessary to disassemble the master cylinder and replace the swollen cuffs, article - "Brake master cylinder"

One brake mechanism does not release (the suspended wheel rotates tightly):

- Jamming of the guide pins at the base of the front caliper, article - “How to replace the front wheel brake caliper”

Replace or lubricate the guide pins. Replace damaged finger covers

- Pistons jamming in the brake caliper body

Remove the brake caliper housing from the base, remove dirt and traces of corrosion from the surface of the housing cylinder and lubricate the working surfaces with NG-213 liquid or castor oil

- Loss of elasticity of the brake caliper housing O-ring

Remove the brake caliper housing from the base and replace the O-ring

- Pads jamming due to severe contamination of the guide groove of the base

Remove the pads and clean the guide groove and ledges of the base from corrosion and dirt

- Weakening or breaking of the tension spring of the rear brake pads

Replace the spring

- Jamming of the rear brake pistons due to contamination or corrosion, article - “How to replace the rear pads

Disassemble the wheel cylinder, clean the parts from dirt and corrosion, wash, replace the dirt covers

- Swelling of the o-rings of the rear wheel cylinder pistons

Replace O-rings and brake fluid

- Lack of clearance between the brake lining and the rear brake drum due to incorrect installation of the automatic adjustment thrust ring

Disassemble the wheel cylinder, eliminate the distortion of the thrust ring

The car skids or pulls to the side when braking:

- Uneven air pressure in tires

Bring the tire pressure up to normal

- Oiling of the friction linings in one of the brake mechanisms

Replace the pads or wash the linings with gasoline, followed by sanding with fine sandpaper and thoroughly removing abrasive dust from the lining

- Scores or deep marks on the surface of the brake disc or drum

Repair or replace the disc or brake drum assembly with hub

- Brake fluid leak in one of the front brake mechanisms or wheel cylinders

Fix leak

- The rear wheels lock earlier than the front wheels due to a malfunction of the pressure regulator or incorrect adjustment of its drive

Adjust or replace the pressure regulator

Insufficient braking efficiency (increased force on brake pedal):

- Worn or oily brake linings

Replace or wash the brake pads

- Incomplete fit of the linings to the drum in the rear brakes

Clean up the protruding areas of the linings. If necessary, replace the pads

- Leak in the vacuum hose connection

Restore the tightness of the connection

- The vacuum brake booster filter is dirty

Wash the filter or replace it with a new one

- The diaphragm of the vacuum brake booster is torn

Replace the diaphragm

- The sealing collars of the vacuum brake booster do not provide a tight seal

Replace the cuffs and clean the cylindrical working surfaces of the valve body and connector

- Violation of tightness in the connection of the cover with the housing of the vacuum amplifier

Restore tightness

- Leakage in the connection between the vacuum booster and the master cylinder body

Replace the O-ring

- Failure of the vacuum booster as a result of brake fluid entering the cavity of the vacuum booster

Replace the master cylinder seals, remove fluid from the amplifier and replace the diaphragm

Rattling in the brake mechanisms:

- Ovality or runout of the working surface of the rear wheel brake drums

Bore the brake drums together with the hub or replace them with new ones

- Breakage of disc brake pad springs

Replace the brake pads

- Wear of the front wheel brake guide pins

Replace guide pins

- Wear of the holes for the guide pins at the base of the brake caliper

Replace base

To hold the car, a lot of force is required on the parking brake handle:

- Sticking of cables in guide shells

Disconnect the cables, clean them from dirt, lubricate the cables and their connections with Liga grease

- Oiling of rear brake linings

Wash the linings or replace the pads with linings

- Parking brake is incorrectly adjusted

Adjust the parking brake drive

Large travel of the parking brake lever handle:

- Large free play of the parking brake drive expansion link in the rear wheel brakes

Adjust the parking brake drive, article - “How to repair and adjust the parking brake

Heating of brake drums when driving without braking:

- Incorrect adjustment of the parking brake drive expansion link

Adjust the parking brake drive

  • - Reduced level of brake fluid in the reservoir of the main brake cylinder in the absence of external leakage in the hydraulic drive
  • - Wear or swelling of the outer cuff of the brake master cylinder

Remove the brake master cylinder and replace the cuff.

Drain the brake fluid from the vacuum booster cover

new

The lubrication system diagram is shown in Fig. 1. Oil pressure in the lubrication system of a warm engine at low crankshaft speed 550–650 min -1

In the article we will consider possible malfunctions of the front axle of the UAZ-3151