My GSX1400 Restoration

[Hooli]

Tip for you before you take them apart.

Take the pads out & pump the lever till all the pistons are nearly touching the discs. It makes the pistons so much easier to remove, even if you've got the fancy 'internal grip' piston pilers.

[SA14]

Thanks! I was JUST wondering about that! Manual says to use compressed air which I don't have. That's a great tip. I was hoping to not have to use too much force to remove the pistons. I was going to wrap my pliers with masking tape or cloth or both.

The manual is also heavy on warning to not reuse any O-rings or seals. I wonder if the O-ring is a standard size I might find at Repco. But given it's not leaking I'm really hoping it won't be cracked.

It also says to rebuild while soaking the pistons in brake fluid. So at what point does the grease come into play? Do the grease and brake fluid "play nice" together? Or should the rubberware be dry before being smeared (lightly I presume?) with the rubber grease?

Presume I know nothing and have little common sense about this because I've never rebuilt brake parts in my life. Going to start right after breakfast. Can't wait now. You've all got me all pumped up! <— see what I did there?

[SA14]

Just thought of a few other things. Cleaning and paint.

Manual the Mexican says to not use petrol or harsh solvents to clean the calipers. I have brake cleaner in spray cans. I'm assuming there are some channels that should be cleaned or blown out. Is it ok to use brake cleaner to shoot through any passages and generally clean then soak it all in brake fluid for assembly? Do I need to go out and buy a little cheap compressor?

Also, when it comes to polishing the cylinders; is it ok to use a fine abrasive like wet 2,000 or 3,000 grit? I have both.

Paint. Sure would be nice to make them all purdy. Don't want to use the wrong colour gold or will general gold caliper paint be close enough? I could always go and get a colour matched gold later but it seems obvious that now is the time for paint. Can't yavr you all pointing and laughing at the noob with fluro green calipers!

This is going to be a great Saturday! I hope for success. Wish I had a tripod for my phone and enough memory to film the whole thing. I'm sure it'd help others but I have neither of those things. I know "it's only brake calipers dude" but I have a mild form of straight faced excitement brewing!

[Hooli]

The idea of smearing them with brake fluid is they don't stick to the pistons & get twisted or pulled out of their seats.

I smear them with red rubber grease & put the pistons in dry. I prefer that way as if water gets in behind the seals & heats up with the brakefluid you get a white crustyness that pushes the seals out & makes the pistons stick. Probably less of an issue down there in convictshire. The reason for red grease is it doesn't make the rubbers (which aren't rubber but neoprene) swell unlike normal grease. It mixes fine with brakefluid if a bit gets behind the pistons.

I've reused all the seals & O-rings etc many times, just check they aren't damaged before putting them back. The O-ring is an off square one, but I found a standard one the right size works when I managed to lose an original one.

There aren't any particularly small passages, they are all obvious too. The only one between the sides has that square section O-ring on, then one between each piston pot. 

Oh & get a big syringe. The brakes are an utter sod to bleed the normal way from dry, but crack the bleed nipple right open & squeeze brake fluid in from there & they fill up no problem. Put a load in each side (closing the nipple on the other side each time) and eventually you'll see it appear in the master cylinder, at that point bleed them as normal to ensure all air is out.

Have fun.

[steve porter]

For what they achieve, you'll be surprised how simple they are inside

[steve porter]

Use a scotchbrite pad with WD 40 on the pistons rather than wet and dry if necessary and then clean  them with brake cleaner

[SA14]

The idea of smearing them with brake fluid is they don't stick to the pistons & get twisted or pulled out of their seats. I smear them with red rubber grease & put the pistons in dry.

So with the o-rings and seals I'll use both brake fluid AND the rubber brake grease or one or the other? Slightly confused about this. The way I read it the manual's telling me everything should be dripping with brake fluid during re-assembly.

I've reused all the seals & O-rings etc many times, just check they aren't damaged before putting them back.

Good to know!

Oh & get a big syringe. The brakes are an utter sod to bleed the normal way from dry, but crack the bleed nipple right open & squeeze brake fluid in from there & they fill up no problem.

Just as well I bought 100 gallons last time! I don't have a large syringe but I do have a small one from when I had to squirt my dogs ears. I can persist with that but the "other bleed nipple" comment lowered then raised my eyebrows a bit. When I remove the banjo bolt I'm presuming all the brake fluid in the system will run out so I'll be starting with an entirely dead dry system - correct?

I was going to try and plug it somehow so as not to lose the fluid entirely. I was thinking to wrap some cloth the electrical tape it tight but from what you're saying it'll all run out and will need refilling in it's entirety and that I should squirt so much in through the bleed nipple that it'll actually pressure it so much it'll come back up through the master cylinder or even go over to the other side and squirt out the other side even? Better get a big syringe then. Pharmacy?

[steve porter]

assemble with rubber grease, much less messy, brake fluid if you don`t have any

[SA14]

Use a scotchbrite pad rather than wet and dry if necessary

A used 2,000 paper will produce very shiny metal. I used it to polish the pad locating pins. I'm guessing it provide a more polish surface than scotch brite but is the idea to make them highly polished or matt finish?

I also presume that any pitting at all on any pistons means I need a new piston? I really hope I find something to suggest the pistons were actually sticking otherwise all this probably wasn't necessary.

I have soft jaws in my vice but I'm guessing it's best to crack the caliper body bolts while it's still mounted on the bike? Also, after I remove the pads and pull the lever to force the pistons out (a bit) am I expecting them to all push out evenly? Or will that be an opportunity to see if any come out slowly to show me that they were the stuck pistons?

[SA14]

assemble with rubber grease, much less messy, brake fluid if you don`t have any

Got it. Thanks for the clarification. I bought that brake rubber assembly grease in the picture I posted a few posts back. I'll use that. They were just kind of washed on the outside anyway so there's no junk and grime present anyway that could get in the way. I'm guessing that a pristine re-assembly is important. I have my stainless roasting dish ready for assembly.

[steve porter]

Use a scotchbrite pad rather than wet and dry if necessary

A used 2,000 paper will produce very shiny metal. I used it to polish the pad locating pins. I'm guessing it provide a more polish surface than scotch brite but is the idea to make them highly polished or matt finish?

I also presume that any pitting at all on any pistons means I need a new piston? I really hope I find something to suggest the pistons were actually sticking otherwise all this probably wasn't necessary.

I have soft jaws in my vice but I'm guessing it's best to crack the caliper body bolts while it's still mounted on the bike? Also, after I remove the pads and pull the lever to force the pistons out (a bit) am I expecting them to all push out evenly? Or will that be an opportunity to see if any come out slowly to show me that they were the stuck pistons?

you will still need to bed the pads in, so  don`t be disappointed if it seems the same at first, personally I would have done that before rebuilding the callipers, but it`s your call, do it in the vice as you will end up with brake fluid on everything if done on the bike, pistons never seem to come out evenly, even after rebuilding.

[SA14]

you will still need to bed the pads in, so  don`t be disappointed if it seems the same at first, personally I would have done that before rebuilding the callipers, but it`s your call, do it in the vice as you will end up with brake fluid on everything if done on the bike, pistons never seem to come out evenly, even after rebuilding.

I was tempted Steve but that shuddering on a hard stop (which was a new phenomenon) plus the grabbing on wheel spin raised my concerns enough to give this deeper clean a go and really have a good look at what's going on with those pistons. It's not really a full proper rebuild as I don't have the seal kit or new pistons. It could be that I was giving the "big hard brake test" a little early without letting that loose pad (which still really baffles me) bed in properly. But a large part of my riding confidence came from having awesome and massive brakes that behaved well on low speed (60 km/h) hard braking tests. I think I'm playing my "best be sure" card today.

All this help from you guys is invaluable. No way I'd touch them with you having my back.  Oh and the only thing I'm going to do on the bike is crack the body bolts and push the pistons out ever so slightly and carefully. I'm curious to see if any one of them stays put but from what you're saying I should expect all 6 of them to push out evenly - right? As long as they come out enough for me to grab them on the bench I'll be happy.

[SA14]

Just found these videos which really helped a lot. What surprised me was how easy the front wheel spun in this first video! Very very different to how my wheel doesn't spin at the moment.

Fast forward to 7:05 to see how easily the wheel spins.

How to Rebuild 6 pot Tokico Calipers
Includes a really cool neat trick for how to remove a stuck piston at 3:35 that I would have never thought of.

How to Prime an Empty Hydraulic System using Gravity

[SA14]

Can't get any pistons out. I can get them to turn using the offset socket method above but one small piston won't budge or turn. I've now damaged that small piston trying to get it out.

Oh well, at least I tried.

[SA14]

Also, all pistons were almost impossible to pull out and really hard to rotate. I was swearing quite a lot. Obviously going to need a full set of new pistons so throwing care to the wind and not concerned about damaging pistons anymore I've managed to get all three pistons out of one half just grabbing them with vice grips and they were REALLY hard to get out. I'm guessing they're all almost seized and one definitely is. Might explain a few things.

Next step a full rebuild kit plus pistons and hopefully I can put them all back together without further incidents. I'll have to order them in from interstate so the bike sits idle for a while. Spewin' because Sunday was a perfect riding day.