Ok guys, since I was going to rebuild, clean and change the seals in my brake calipers, I thought I'd make this tutorial.

Everyone has his own way but this is mine and I'm sticking to it.

It might come in handy for those who never done it or are having problems with their brakes.

It might be a sticking piston, a leaking seal or a sticking floating button and without digging in you can never know.

In my case I had a sticking piston on the left caliper that was causing some vibration and unbalance when coming to a stop.

This is specifically for the F4i but all opposed pistons calipers will be pretty much the same.


*Old tooth brush
*T45 Torx key
*8mm for bleeder nipple
*12mm wrench for caliper bracket bolt
*14mm for banjo bolt
*Torque wrench
* Allen key to remove brake pads/dust shields
*Precision screwdriver or similar,preferably plastic
*Wire brush

Consumables

*Rubber gloves
*2 Small Plastic bags
*2 pieces of corrugated cardboard
*Rags
*Brake fluid
*Brake Cleaner Spray
*Silicone paste/Rubber grease
*Loctite for bolts
*Seals if replacing (f4i part# 06451-MCJ-405/06451-MBW-405)

 

Ready?

Ok, the first thing you want to do is to remove the pins that hold the dust shields from the calipers.




At this point, I slightly unscrew the banjo bolts at the caliper but leave it tight.

Also, with the Torx key, slacken the 4 calliper bolts that hold the halves together, cuz' it’s much easier to do while attached to the forks than on a work bench. Not all the way out, just enough to brake the seal that has formed

Unbolt the bracket bolts and grab the caliper



Put a piece of corrugated cardboard in the middle of the caliper between the pistons



Grab the front brake and pump it until the pistons grab the cardboard and stay there tight. I do it like this cuz' it's easyer to pull the pistons out when you split the caliper halves.

Now, grab one bag and put it around the caliper



Unbolt the banjo bolts completely, remove the caliper and leave the bag wrapped around the line, catching all the brake fluid

Repeat on the other side.
Now, take your caliper to the work bench it's cleaning time.

 

Take your calipers to the work bench and completely remove the 4 bolts
Watch out for the small seal between the 2 halves



Depending on how bad your pistons are, they might come out with your hand, sometimes I’ve had to use pliers.

If you need to do this, use electrical tape to tape around the teeth a few times so as not to damage them and also wrap a cloth around the pistons and pliers.
Try to grab as little as you can on the piston.
Hold the calliper half and use the pliers to grip the piston and rotate it in the calliper whilst pulling at the same time. It can take a while, but it will eventually come out.
Repeat the process for the other pistons.

When you see the seals, remove them very carefully and bin them if you have new ones.

Cleaning time

With some brake fluid and the toothbrush, soak the calipers and clean them, especially the seal gooves



Clean seals if you are reusing them

Clean the pistons thoroughly



Also, clean the calliper bolts with a wire brush



Clean bleed nipples

Rinse everything with hot water

This is what it should like after cleaned



After all is cleaned, grab your brake cleaner spray and give it a blast on the calipers to remove anything that might have been left behind. It also helps to remove any moisture and water.

If you have access to an air supply, now it's a good time to blow on them

Pack the seal grooves with some rubber grease and fit the seals.



Remove any excess grease

Once they are all cleaned, dip a finger into the old brake fluid and coat the piston chamber and seals in the calliper halves, then dip the piston into the fluid and coat them before refitting to the piston chambers. This will help them slip past the seals with ease.

Refit the small calliper half seals, again coating the seals in the brake fluid

Apply some Loctite to the threads



Make sure the seals are seated correctly before joining the calliper halves.
Screw the halves together, but don’t over tighten.

I leave the torqueing for after they're fitted to the bike, it's much easyer.


That's it, you now have fresh brakes! Just install in reverse order.



At this time I usually clean and oil up my floating rotor buttons, cuz'if they start to stick you might warp your rotors.

 

Thanks for the write up on how this is done .... nice pics and great walk along instructions ...

 

Your welcome man, it's nice to retribute.

Somebody once told me that knowledge means nothing if you don't share it. So, I'm sharing

 

Wow! Very smooth, I've done this before, but this would have taken a lot of the "hmmm" factor out. Very nice documentation. Thanks for sharing.
Ern

 

awesome work and thanks for the pix. Looking to do this on my calipers to powdercoat them. bookmarked!

 

If you're powdercoating them be sure to seal off the working parts really good, you do not want paint in there.

I was thinking of that too but my brother can't do it now so it will stay for another time. Shows us the the result after, bro.

 

Hey Slick,

What kind of rubber grease are you using? Also, how long after applying the Loctite do I have before torquing down the bolts? I assume I can't let it sit for a week or two before reinstalling them?

Edit: Is there a difference between 06451-MCJ-405 and 06451-MCJ-751, besides the price? RonAyers has both listed for the same seal, but it looks like it's going to be somewhere between $80 - $150 to redo all three brake calipers, depending on which seals are acceptable.

 

The grease is regular silicone/rubber which comes in a tube. I don't think you have the same brands over there.
Maybe some other user can chime in on brands...?

Regarding the Loctite, it should be used immediately before assembly and you do have the chance to torque it after a while but I wouldn't recommend that long. 48h tops.

I had the same question as you, it seems the seals are listed as being the same but they're actually not.
Talked to a friend that work for Honda dealer and unfortunately, the cheaper ones are for the F4 up to 2000. He just doesn't know what the differences are but he thinks that Honda revised the thickness of the rubber The costier are the ones you want for the F4i.

You can do the same as I did.
Remove all seals and dispose of the dust seals. Clean and inspect the oil seals and if they look ok, not ripped or streched, it'll be safe to reuse them. But at least get the dust seals, those are the ones that get "abused". The ones closer to the out side of the caliper.

Hope it helps...