DISMANTLING OF MY ORIGINAL BRAKE MASTER CYLINDER
After failing every attempt so far to fix my car's current spongy brake pedal feel problem over the last 2 months or so, It was time for me to take a big step back on further diagnosing the problem and instead I now wanted to alter my focus on trying to increase my mechanical experience, knowledge and understanding of the individual components within the braking system. I hope that this exploratory new process I am about to undertake, will eventually lead me to find the problem part that has been causing me to be unable to bleed all of the air out of my braking system.
Targeting a single mechanical part at a time, I want to learn how to disassemble each part down to its most basic components as much as I can, from there figure out and learn how that specific mechanical part functions inside and out. Once I understand how that part works, I can then know if the part is faulty and how that part can be repaired in the future. Once I have solved the spongy brake pedal problem using this new learning experience, I can then expand my learning process to include other systems on the car such as the power steering system and maybe some electrical components as well.
Starting off this new process, will me the disassembly of my original factory brake master cylinder which was present on my car when I brought it back in 2006 and then I replaced it with a 2000spec later model variant in 2011. The original BMC was then reinstalled back onto the car during the last time I attempted to do a brake caliper and rotor change on my car back in 2017 where my Dad assumed that the later model BMC was faulty. Dismantling this BMC and inspecting the 2 internal pistons and the bore of the cylinder will help me to verify whether or not this brake master cylinder is either good or bad.
https://i.postimg.cc/jjCNP71t/1-Before-Photo-2.jpg
https://i.postimg.cc/YSjgYWPt/1-Before-Photo-3.jpg
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The first step is to remove the primary and secondary pistons found inside the master cylinder. I mounted my BMC into a vice and then removed the snap ring cover cap found at the end of the bore section on the cylinder.
https://i.postimg.cc/N0VX40hy/2b-Piston-Removal-Rear-Cover-Plate-Removal-using-Pick.jpg
https://i.postimg.cc/nL5mkL8K/2c-Piston-Removal-Rear-Cover-Plate-Removed.jpg
Using a pick, I gently pried on the lip of the primary piston located at the end of the bore until it had come out far enough, so that I could pull the piston out by hand the rest of the way.
https://i.postimg.cc/cJj3mJqQ/2d-Piston-Removal-Rear-Piston-Removal-Using-Pick.jpg
https://i.postimg.cc/nrfQywhs/3b-Front-Piston-After-Removal.jpg
https://i.postimg.cc/xCzzFSn1/3b-Front-Piston-After-Removal-Close-Up.jpg
One down and one to go but the secondary piston was going to require a little bit more effort from me to be able to remove it as it was still located deep down inside the bore of the master cylinder and there was no way I was going to be able to pry it out using the same method I had done for the primary piston. I initially tried using a magnetic pickup tool to try and connect to and pull the piston out from the bore of the cylinder but no matter what I did, the magnetic on the pickup tool just wasn't strong enough to be able to hold onto back end of the piston with enough force to allow me to pull the piston out from inside the master cylinder.
So using the information I had researched on several YouTube videos about how to disassemble a brake master cylinder, I switched over to using compressed air to try and push the secondary piston out of the bore of the cylinder.
https://i.postimg.cc/g05hD09t/2f-Piston-Removal-Front-Piston-Removal-Using-Blow-Gun-From-Compressor.jpg
Using a blowgun at the outlet valve port for the rear brakes on the BMC, I shot compressed air into the bore of the master cylinder and in no time at all the secondary piston had popped out from the bore of the cylinder.
https://i.postimg.cc/3w6GBwMn/2f-Piston-Removal-Front-Piston-Removal-Piston-Popped-Out.jpg
All that was left to do was to pull the secondary piston out the rest of the way by hand.
https://i.postimg.cc/bJttFj8L/3a-Rear-Piston-After-Removal.jpg
With the primary and secondary pistons now free of the master cylinder, I thoroughly inspected the rubber seals on both pistons to look for signs of tears in the rubber O-ring seals and or deformities. But from what I could see, both the primary and secondary pistons and all of the rubber O-ring seals attached to each piston were in perfect condition and there were no signs of any kind of damage to the pistons or seals of any kind.
https://i.postimg.cc/yxhSsXDc/3b-Piston-Layout-Inside-The-Cylinder.jpg
I was hoping from there to remove the reservoir bottle on the top of the bore of the cylinder but after several pulling and prying attempts to dislodge it off of the 2 rubber grommets holding the reservoir to the cylinder with no signs of movement from the reservoir, I decided to just leave it in place otherwise I could damage the plastic reservoir tank trying more aggressive removal methods.
So now that I had reached the level of disassembly I was willing to go to with this brake master cylinder, I wanted to thoroughly clean out the entire unit so that I could inspect the bore of the cylinder for signs of damage.
I placed the BMC into a suitable sized container and filled it with a degreasing cleaning solution and place it into my ultrasonic cleaning machine and put it through a 30 minute 60 degree cycle to remove all of the remaining old brake fluid residue found inside the bore and reservoir of the BMC after its disassembly.
https://i.postimg.cc/mk3FBNP5/4a-Cleaning-Ultrasonic-amp-Simple-Green-HD-Cleaner.jpg
After its cleaning cycle in the ultra sonic machine, I then blow dried the BMC thoroughly to leave me with a spotlessly clean almost brand new looking brake master cylinder.
https://i.postimg.cc/Pf1DWhS8/4b-Cleaning-Ultrasonic-amp-Simple-Green-HD-Cleaner.jpg
https://i.postimg.cc/XN95f3s2/4d-Cleaning-Ultrasonic-amp-Simple-Green-HD-Cleaner.jpg
With the BMC clean and dry, I inspected the bore of the cylinder to find it as well in perfect condition with no marks, scuffs or damage present.
https://i.postimg.cc/8kLvRDZB/4c-Cleaning-Ultrasonic-amp-Simple-Green-HD-Cleaner.jpg
The only thing I noticed after the cleaning process was this metal disc cover on the end of the cylinder that faces the front of the car, began to start coming off the adhesive that attached it to the body of the master cylinder.
https://i.postimg.cc/tCyxDfcv/5a-Front-Disc-Cover-Falling-Off.jpg
Once I removed the cover completely, there was a female hex headed bolt behind the cover.
https://i.postimg.cc/xTYzg7Zw/5b-Front-Disc-Cover-amp-Adhesive-Removed.jpg
And with all of that now done, I can safely assume that this brake master cylinder is in perfect working condition and there is no indications that it is faulty in any way. There is no damage to the internal bore of the cylinder and the components of the primary and secondary pistons are also in good condition.
I was definitely very happy with the outcome of my first disassembly process on one of the components of my car's braking system. I set myself a reasonable goal to achieve and using the information I had gathered from my research to effectively perform the task required to disassemble the unit down as much as I was happy with and once disassembled I was able to clean and confirm that my original BMC is not faulty and was not the cause of my car's inability to bleed all of the air out of the braking system.
My new plan was definitely working as i intended it to and I couldn't wait to continue to pull apart more parts and learn more about my car then I had ever done be before and thought possible.
By
DJ_Party_Favor ·
black with camoflague front about 11 15 today large rear spoiler