DIY Brake Master Cylinder rebuild
Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!
Aim: to stop your brake pedal from creaping to the floor. ( help make your car stop )
Required:
- OEM Brake master cylinder rebuild kit ( from your local Honda dealer )
- 500ml Brake fluid
- cir clip pliers
- allen key set
- 10mm spanner
- 12mm spanner
Do you have a Honda that has a dodgey brake pedal ?
does your pedal creap to the floor when you press the pedal ?
is it wors on hot days/weather ?
if so, then your brake master cylinder is rooted. You can try to bleed the brakes, but if the brakes are ok most of the times and sometimes it does the above symptoms you will have to replace or rebuild it.
a rebuild kit will cost you about 90 to 100 bucks, a new master cylinder will set you back about $250 to $280 depending on your car.
you will most definantly have to replace your master cylinder if it bore is badly scorred causing bypass, but 9 times out of 10 its due to wear on the seals on the two pistons.
Caution; During any part of DIY make sure you do not spill brake fluid on your paint work. It will get damaged from the brake fluid.
Steps: 1
suck out the brake fluid from the master cylinder resivour
http://ecu-man.com/diy/bb6-bmc/BB6100.jpg
Steps: 2
undo the two brake lines using your 10mm spanner (red circles bellow). Be carefull not to round the nuts. if you do carefully use vice grips.
http://ecu-man.com/diy/bb6-bmc/BB6102.jpg
STEP: 3
undo the master cylinder mounting bolts that hold it to the booster. ( blue arrows above and bellow pic )
http://ecu-man.com/diy/bb6-bmc/BB6103.jpg
STEP: 4
remove the seal from the booster if it isnt already on your master cylinder ( red arrow bellow pic ). do not damage it as you will have to reuse it on some cars, most kits will have a replacement. aslo you do not want to do a double sealer. causes vauum leaks
http://ecu-man.com/diy/bb6-bmc/BB6111.jpg
STEP: 5
place your master cylinder on a bench, use a rag as you bench will cop some brake fluid. undo the allen key bolt in the pic bellow ( red circle ) and slide the pin out. note it has an aluminum crush washer.
http://ecu-man.com/diy/bb6-bmc/BB6114.jpg
STEP: 6
undo the cir clip at the end of the master cylinder ( red arrow pic bellow ), then pull out the 1st piston along with the sleeve.
http://ecu-man.com/diy/bb6-bmc/BB6115.jpg
http://ecu-man.com/diy/bb6-bmc/BB6116.jpg
http://ecu-man.com/diy/bb6-bmc/BB6118.jpg
STEP: 7
remove the 2nd piston from inside the master cylinder ( red arrow pic bellow ), use long nose plires, careful not to touch the bore ( blue arrow pic bellow ).
inspect the bore for sevire damage
http://ecu-man.com/diy/bb6-bmc/BB6119.jpg
http://ecu-man.com/diy/bb6-bmc/BB6120.jpg
STEP: 8
replace the pistons, start with the 2nd piston, the last one you removed. before we put it back in the master cylinder you have to lube the seals with the pink grease that comes with the kit.
apply grease to the two seals shown in the pic bellow by the 2 yellow arrows.
http://ecu-man.com/diy/bb6-bmc/BB6122.jpg
STEP: 9
reinsert the 2nd piston back into the master cylinder. Spring end in 1st. Make sure the slot in the piston lines up with the ( green arrows in the pic bellow ). Use your long nose plires to put the piston in the bore, then slide it in using a screw driver.
http://ecu-man.com/diy/bb6-bmc/BB6124.jpg
STEP: 10
change the aluminium crush washer on the long allen key bolt. red arrow bellow.
http://ecu-man.com/diy/bb6-bmc/BB6126.jpg
STEP: 11
Push the 2nd piston in compressing the spring maintain the pressure on the spring and slide in the long allen key type bolt into the master cylinder. if you have lined up the 2nd piston correcely it should slide right in. do not force it.
now tighten the allen key bolt.
STEP: 12
lube up your new 1st piston seal. ( yellow arrow pic bellow ) and slide it into your master cylinder.
http://ecu-man.com/diy/bb6-bmc/BB6125.jpg
STEP: 13
now its time to replace the seals in the sleeve. first replace the outer seal, gently remove the old one with a screw driver. apply the pink type grease on the sleeve itself then on the new o ring, then put the new O ring on the sleeve.
http://ecu-man.com/diy/bb6-bmc/BB6129.jpg
STEP: 14
now pay extra attention to the way the inner seal sits in the sleeve. take it out with with a small screw driver and apply pink grease in the channel where the seal sits. apply pink grease to the new inner seal. push the new seal into the sleeve and menuvour it with your fingers to sit in its channel the same way the old one did.
http://ecu-man.com/diy/bb6-bmc/BB6130.jpg
STEP: 15
time now to fit your lubed up sleeve to the master cylinder. lube up the shaft of the 1st piston with the pink grease.
http://ecu-man.com/diy/bb6-bmc/BB6133.jpg
http://ecu-man.com/diy/bb6-bmc/BB6131.jpg
http://ecu-man.com/diy/bb6-bmc/BB6132.jpg
http://ecu-man.com/diy/bb6-bmc/BB6135.jpg
STEP: 16
put the 1st piston in the master cylinder if you took it out to fit the sleeve. put the new cir clip on and push it down with a screw driver to make sure 100% it is seated in its channel.
http://ecu-man.com/diy/bb6-bmc/BB6136.jpg
http://ecu-man.com/diy/bb6-bmc/BB6137.jpg
STEP: 17
open up your white gease satchet and apply some to the booster seal and to the master cylinder and the shaft of the 1st piston. smear it all around
http://ecu-man.com/diy/bb6-bmc/BB6145.jpg
STEP: 18
now fit the master cylinder to the vehicle in revers from the way you took it off. do not put the brake lines on just yet.
STEP: 19
bleed the master cylinder.
- put a small plastic bag under the two holes where the lines go into the master cylinder. the idea is to catch brake fluid as you bleed the master cylinder.
- fill your master cylinder with brake fluid.
- get your helper to press down on the brake pedal then block the two holes on the master cylinder with your fingers ( to seal the holes ) then get your helper to lift the pedal. uncover the holes. press down on the master cylinder then cover the holes then up on the pedal.
repeat this untill you get a good steady stream of brake fluid coming out from both holes.
STEP: 20
refit the brake lines to the master cylinder. tighten them up nice and tight ( not superman style )
and now its time to bleed the brake as normal. bleed all four wheels.
thats it
this should take half an hour to compleate, but take your time do not rush.
let me know if you have any questions
thanks to VTEK for his help with this Job and taking happy snaps :)
Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!
