Brake Wheel Cylinder Parts . Toyota L Engine Guide

Brake Wheel Cylinder Parts

Wheel Cylinder Assembly

This wheel cylinder assembly has its parts that we need to understand their functions. Please follow the parts below and see if I missed something and don’t hesitate to mention in the comment box what are your ideas. Let’s learn together by sharing our knowledge concerning this essential part of the brake system.

Brake Wheel Cylinder Parts-Toyota Wheel Cylinder Assembly

Dust Boot or Cylinder End Cap

These caps protect the cylinder from being filled with dust. It is important so the piston will stay clean and smooth in its movement. When there are no caps on both ends of the cylinder either, water, dust or mud will accumulate on the piston passage and it will cause corrosion on both the cylinder and the piston resulting in the oil leakage.

Brake Wheel Cylinder Parts-Dust boot/wheel cylinder end cap

Cylinder Pistons

The cylinder pistons are responsible for pushing the cylinder cups. When the brake pedal is pushed it will also push the oil that will push the cups on both ends to give pressure to the brake linings against the brake drum.

When the return springs compress the brake shoe, the brake shoe will push the pushrod that will press the piston.

Brake Wheel Cylinder Parts-piston

Cylinder Cups

The cylinder cups are the ones that seal the brake fluid from leaking. Every time the brake is needed the cylinder cups move back and forth the cylinder. Let’s say the brake pedal is pressed then the brake fluid will be pressed inside the wheel cylinder. The oil will fill the cylinder but it will not burst out so it will press the cups outward pushing the pistons outward.

When these cups are perforated it will allow oil leakage and the brake can be less effective in halting the car.

Brake Wheel Cylinder Parts-cylinder cup

Cup Spring

The cup spring is responsible for pushing back the cups every time they are pressed. It also functions as the stabilizer of the cups so they’ll not flip inside the wheel cylinder.

Brake Wheel Cylinder Parts-cup spring

Breather Screw

The wheel cylinder breather screw is an important part of the wheel cylinder assembly. This is what you need when you fix the brake filled with air. It is not good and as effective when the brake fluid tube passages are filled with air. To remove the air inside the brake fluid tube passages, this breather screw does the job. 

To remove the air inside fluid passages you need someone to assist you. One will pump the brake pedal and press it to the floor then one will loosen this screw to breathe out air. Temporarily tighten it and let the person pump again the brake pedal then press it to the floor until this screw is loosened again to release air. Do the procedure until the brake pedal becomes stiff enough and it will not reach the floor, that means all brake fluid is inside the tube passages.

Brake Wheel Cylinder Parts-breather screw

Thank you for reading this post and I hope it gave you an idea of how this assembly works with the whole brake system.

I am happy if you would contribute your opinion regarding this discussion so we all could learn. Drop your comment on the comment box and I will be willing to respond to any questions.





4 thoughts on “Brake Wheel Cylinder Parts”

  1. Complete novices like me and for other people who does not know anything about car engines or brakes and all that this is a great post to learn from. May your mechanic have done some mistakes but learning from articles like this you might be able to point out some corrections be it gets too late, thanks for this beautiful article. I would pay more attention to my vehicles engine and try to see the what’s and what not. Maybe one day when I replace a brake wheel cylinder I would take it apart to so how this thing really is. 

    • Thanks for coming to the discussion. I am learning much from my old car for I do it myself the things I am sharing on this website. It’s really satisfying and fulfilling when you discover that it’s not so difficult to fix an issue related to the brake system.

      I am willing to share to the best I can on anything that can help our readers and interested individuals like you.

  2. Hey There! Thanks for sharing this, I like the brake wheel cylinder part as the wheel cylinders are very good quality and exact fit for my 1988 Ford F-150 (rear left). No issues with install and the work as intended. A vital part to restoring or repairing drum brakes on any vehicle. 

    • Hi! It’s good you have restored your wheel cylinder. I think that’s the best move for that model. I am also replacing the wheel cylinder of my 1977 AUV. History repeats itself in just replacing the cylinder cups. They are leaking after a year. 

      Thank you for joining the discussion.


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