Installing Galfer rotors and rebuilding front calipers

[ssevy]

One of several winter projects was upgrading the brakes on my Tiger. I had changed the fluid regularly since first purchasing it used, but had never disassembled the calipers and rebuilt them with new seals. Having done this job on my Legend last year (during which I discovered the miracle of red rubber grease), I had made this a priority on this winter's "to do" list. Here are some photos and descriptions to add to the knowledge base here (there are already some great brake threads in the "stickies", but I always like to read as many different threads as possible before tackling a new job which I have never previously experienced, so maybe someone will find an additional tip here that may help).

I keep a brass wire brush on an old electric motor, and use this to clean up parts for most of the work I do. Road crews in upstate New York are very generous with sand and salt throughout the winter, and unfortunately, there are often patches of this stuff around long after winter has ended, so suspension and brake and drivetrain components are usually caked with some type of nasty material or corrosion. This is also the reason that I use Never Seize whenever I can, as it makes things so much easier to disassemble the next time around. I mention these points because you will see both the wire wheel and the Never Seize later on in the photos.

My photos begin at the point where I am prepping the wheel to mount the new brake rotors. I actually held up the wheel to wire brush the bolt posts where the discs are attached, but this required both hands, so no photo of that :icon_wink:
By the way, I had the wheels off to seal them to run as tubeless, and that job turned out very well (another thread on that).

Here I am using my wire wheel to clean up all of the hex bolts that hold the rotors in place:


Using a brass bore brush to clean out the old blue thread locker in each bolt hole:


Bolting the new Galfer disc in position (these are one part number for both left and right, as they are a symmetrical design):


Letting the blue Loctite spread around the bolt evenly before inserting it:



Before removing both calipers from the front, I used the fluid in the system to get one set of pistons out to where I could easily wiggle them out by hand. To do this, I used a piece of scrap aluminum with a hole drilled in like this (a piece of thin wood would work as well):


The screw allows me to hang the plate in the other caliper to keep those pistons from popping out:


Pumping the brake lever moves each pair of pistons outward. Depending on the nastiness of the funk on each piston, some may come out faster than others. The plate on the one caliper will stop the two pistons on that side from dropping out, but you will want to watch the other side and use another plate or screwdriver to block one piston if the other is sluggish. You want both as far out as possible without them actually popping out.
Once you have done that, remove the banjo bolt and let the fluid drain into a glass jar. Meanwhile, loosen up all of the other hex heads and other bolts so that you can turn them by hand once the caliper is off the bike (While you can use a vise for that, it is difficult to hold an irregularly shaped object such as these calipers without slipping or possibly damaging it, so save yourself the potential and do it on the bike). Once you have everything loose, go ahead and loosen the remaining two caliper mounting bolts and take the caliper itself to the bench, being careful not to spill any brake fluid. Dump any fluid into another jar or a cloth, and then disassemble all of the parts and lay them on a towel or newspaper (If your memory is shite or you may have to leave this job and come back a few days later, take some pictures before removing pieces, so that you can easily reassemble). I use a dental pick to carefully pry out the old seals in the cylinders, and very gently remove the two rubber pieces that cover the two shafts of the moving caliper piece. It takes a careful hand not to tear these, so go slowly and spray some lube between the rubber and the metal tube it passes through if necessary. I turned the entire rubber piece a few revolutions to be sure it wasn't sticking to the metal, and then pulled it out, closed end first.

Here is what the inside of the cylinders looked like:


The brown mung was congealed on the downhill side of each piston:


Here's the stainless spring that applies tension to the pads:


Here are the pistons. Left is as it came out and right is after wire brushing. Fortunately, I had no pitting. If you do find pitting, replace them:


Here is the spring clip getting cleaned up on the wire brush. Vise grips work great to hold small parts for wire brushing:


Our calipers were used on a bunch of bikes, and I find it easier to get Honda parts locally, since I have no Triumph dealer around me. Here is the Honda part number for one set of seals, which do just one piston (you'll need four sets for the entire front end):


Here are the two grooves for the seals in the cylinders. Wider seal on bottom and skinnier one on top:


In addition to wire brushing on the large brass wire wheel, I also used a plumber's copper cleaning brush with some steel wool to clean the inside of the cylinders with my drill. Brake cleaner and compressed air finished the job, with the final results looking like this:


Here's a good view of those clean grooves where the new seals will be installed:


Wire brush all of the other metal parts, and then place everything on a clean towel or paper to begin reassembly. I discovered red rubber grease last year when overhauling my Legend calipers, and was shocked at the improvement in braking when I was finished. Red rubber grease is specifically made to not harm brake fluid as it does come in contact with it, and besides making the pistons move so much more freely and smooth, it also helps prevent corrosion and grime buildup in those grooves that hold the seals. They are a perfect location for moisture to collect, and the red rubber grease helps prevent that.
I also use some thick clear grease designed for swimming pool use on those two shafts that are covered by the rubber covers. Since pool chemicals are corrosive, I think this grease is a great choice for those shafts which may get some road salt or other road chemical on them.
Finally, I used some Boeshield T9 spray on the inside on the inside of the pistons (not the outside where it touches the cylinder). Spray some inside, then turn the piston until the sides are all coated. Dump out the excess and let them dry. This step is to help prevent corrosion inside the piston cups, which are exposed to the weather.

Here is the red rubber grease, which I could only find on ebay here in the US:


This is the swimming pool grease for the caliper pins. I think bulb grease is pretty similar:


With everything clean and at hand, lube up the new seals with red rubber grease and install them. I find it easiest to stuff the big one in first, and then slide it back towards the outside until it slips into the groove. Follow with the skinny one, then carefully push the piston into the cylinder until it bottoms out. Using the grease, I find these slide in effortlessly.

Here are the two pistons back in place. You can just make out a little red rubber grease along the seam at the top lip of each piston, and note the golden color of the inside of each exposed piston from the T9:


Push the spring clip into place. This photo shows the correct orientation if you forgot to take a photo :icon_wink::


Carefully insert the two rubber pieces. Again, the long one is fed open end first into the metal collar where it goes. Lube both shafts of the floating arm with Jack's grease, and insert the shafts. If the shafts bottom out but then push back out a bit, you have some air in behind the grease. Use a small pick to successively open up each rubber collar as you bottom out the shaft to burp the air out. Combined with a good piston rebuild at the lever end, this nicely sealed system will not only apply the brakes pads perfectly when squeezing the lever, but the vacuum action of the fluid returning towards the master cylinder will pull that pad back away from the rotor and prevent rubbing and excessive wear. You will be shocked at how much better your brakes work!

Here's a shot to show the floating arm in place:


The two slide pins receive the brunt of the corrosive action, as you can see from this photo. Note even the polished one isn't perfect:


Depending on how bad they are, you may need to replace them. While it is tempting to cover them with grease, I think you will attract a lot of debris by doing so, so after polishing the shafts, I sprayed them with the Boeshield T9, and then used Never Seize on the threaded part, as this can't shed onto the pads. Don't overdo the Never Seize to be sure it doesn't come into contact with the pads (It would become Never Brake ).

Here is the new inner pad pushed into place and ready for the slide pins to be installed:


Here are the slide pins peeking through ready for the outer pad to now be installed:


Here are both pads in place (I used Carbone Lorraine pads this time, and will report back with a review in a separate thread once I have some miles on them.):


Initially, I install the old bleed screws, as I refill the system from the caliper end with a syringe. Once the system is all refilled and has no air in it, I replace the old bleed screws with Speedbleeders, but I keep the old ones in case I need to refill the system again in the future.

You are now ready to reinstall. I do everything as tight as I can on the bench not using a vise, and then check all of the torques once it is mounted back on the fork. Don't forget to wire brush those two caliper mounting bolts as well. I use Never Seize on those too. By the way, you can use either a hex bit or a star bit on those caliper mounting bolts. Having tried both, I think the Star bit gives you better purchase with less threat of rounding out the shoulders.

Now, the other caliper is done the same way, except once you have loosened the fasteners and removed it from the fork, you'll need to leave the bleeding screw tight and use compressed air to pop the pistons the rest of the way out if they won't wiggle out. Use that stop plate again, wrapping the whole thing in a rag, and then apply quick taps of air into the banjo bolt hole with a rubber tipped nozzle that is leak proof.

Here is the result:


The larger center hole is where the compressed air goes in:


Just a couple of important reminders:

1- Be sure both washers are in place on the banjo bolts.

2- Double check all of your torque values once you have the calipers remounted on the forks.

3- Refill the system with Dot 4 fluid using whatever technique you prefer (if you have never done this, I recommend using a syringe. See my post in the Stickies).

Go ahead and install the new Speedbleeders in the calipers and check for any air. Even though they have a factory applied sealer on the threads, I always use some Teflon tape as well. Just be careful not to get it where it might plug the outlet hole. Here's the part#:


Good luck!

[nickjtc]

Well done, that man!!

[Timbox2]

Very good report , but one question, why didnt you use the red rubber grease on the slide pins? I have no idea what swimming pool grease is but if its not compatible with rubber it may swell the boots.

Be interesting too to find out your thoughts on the Carbonne Lorraine pads, I used them on one of my previous BM's and was very impressed.

[Sin_Tiger]

I have no idea what swimming pool grease is but if its not compatible with rubber it may swell the boots.

So long as it's not "Mineral" based it'll be fine.

[ssevy]

Very good report , but one question, why didnt you use the red rubber grease on the slide pins? I have no idea what swimming pool grease is but if its not compatible with rubber it may swell the boots.

Thank you for the great question! Jack's is made to coat the rubber o-rings themselves in all of the union joints in a pool's piping system, so I knew it was rubber safe. It is much thicker and more clingy than the red rubber grease, and so should remain in place better. Lastly, the temperature range is extremely wide, and so caliper performance should not be affected by weather or hard braking.

[Timbox2]

Thank you for the great question! Jack's is made to coat the rubber o-rings themselves in all of the union joints in a pool's piping system, so I knew it was rubber safe. It is much thicker and more clingy than the red rubber grease, and so should remain in place better. Lastly, the temperature range is extremely wide, and so caliper performance should not be affected by weather or hard braking.

Fair enough, wonder if it can be got in the UK, sounds good stuff. Im guessing its Silicone based maybe?

[ssevy]

It feels and looks just like the little packets of bulb grease, which I think is dielectric grease? Probably silicone based.

[ssevy]

Update:  The pads were not very impressive. I went back to HH.

[Beernard]

Ssevy, that was great. I admire your attention to detail in your work and your reporting. Fantastic.
Regards, Bern.