Brake Service - Simple Tool Tip

[barny7655]

if your careful you can suck them in using a brake sucker on the nipple, but you have two pistons , need two sets of hands, or press them in with a clamp and a piece of plate,  brake grease on calipher seals,not to much may help,a lot  forget to unscrew the bleeder nipple , never had trouble with this with genuine seals  KDM  , take your time and make sure the pistons are square

[hogpipes1]

.... after making sure there is room in the master cylinder reservoir to accept the fluid that you are pushing back up the line.   

Good time to change fluid and push all that dead crap out of the M-C .

[hogpipes1]

Disappointingly, I still have brake binding issues. My rotors are out of spec I'm sure so that's not helping I expect.
Off out to the garage to take another look. I kind of enjoy this problem solving in a perverse sort of way. I guess most of us do. All part of getting to know the bike.

Time to pull the calipers apart. The last set i did had some very hard residue on the pistons.
With 10 years on them, probably worth new seals anyway.
Not sure on the parts availability though.

[attach=0,msg1328222]

Bought a seal kit (Cycle Pro LLC 19258M) but struggling to get the pistons back in. It's incredibly tight and just binds-up. I've checked for a chamfer but there's no measurable difference. If I put them in one way or the other I reckon I can feel a lip on the inner edge as should be the case. I'm just lubing them with brake fluid but did see one YT video where the guy was using dielectric grease.

Any thoughts? Just fitted a brand new set of rotors and can't afford to have these brakes bind-up on them once they're assembled. Man, I've so many hours in this job now. You'd think it'd be straightforward.

Thanks in advance guys.

Put the pucks in the freezer for a while , might be enough to drop in.

[speedzter]

Bought a seal kit (Cycle Pro LLC 19258M) but struggling to get the pistons back in. It's incredibly tight and just binds-up. I've checked for a chamfer but there's no measurable difference. If I put them in one way or the other I reckon I can feel a lip on the inner edge as should be the case. I'm just lubing them with brake fluid but did see one YT video where the guy was using dielectric grease.

Any thoughts? Just fitted a brand new set of rotors and can't afford to have these brakes bind-up on them once they're assembled. Man, I've so many hours in this job now. You'd think it'd be straightforward.

Thanks in advance guys.

Have you tried using the old seals ?

[klammer76]

I had a bit of a struggle getting my pistons back in when I was doing a switch to 2008 Brembo calipers on my 2002 FLH. I Disassembled and cleaned them thoroughly to use dot 5.

I used very light smear of silglide around the seals and installed the pistons using a slight twisting motion. The key was having the piston straight to the bore and seals. Once you get one to go and get the feel the rest become easier.

I id not use brake fluid as the 2002 SM for the old style calipers I was removing stated not to use brake fluid. There are no instructions in the 2008 SM as to rebuilding the Brembo calipers. Guess they want you to buy new...Not.

[Molly]

never had trouble with this with genuine seals  KDM  , take your time and make sure the pistons are square

Thanks. Interestingly, these seals are available in the US for about $25 so they're pretty cheap (read, poor quality). Over here in NZ they cost me close to $120.... I dread to think what a quality set would cost.

Put the pucks in the freezer for a while , might be enough to drop in.

Nice idea but I'm still concerned that they shouldn't be so tight.

Have you tried using the old seals ?

I have them back in now in the hope that all that cleaning and a bit of dielectric grease would free them up a bit but they're still dragging.

I had a bit of a struggle getting my pistons back in when I was doing a switch to 2008 Brembo calipers on my 2002 FLH. I Disassembled and cleaned them thoroughly to use dot 5.

I used very light smear of silglide around the seals and installed the pistons using a slight twisting motion. The key was having the piston straight to the bore and seals. Once you get one to go and get the feel the rest become easier.

I id not use brake fluid as the 2002 SM for the old style calipers I was removing stated not to use brake fluid. There are no instructions in the 2008 SM as to rebuilding the Brembo calipers. Guess they want you to buy new...Not.

That's exactly what they expect you to do. Who throws away expensive calipers just because the seals need replacing?

Thanks for the advice though. I'd just be a bit concerned that if I did manage to get the pistons past these aftermarket seals that they'll still drag as they'd be incredibly tight.

Anyway, thanks so much for your advice guys. It's much appreciated.

[sfmichael]

if your careful you can suck them in using a brake sucker on the nipple, but you have two pistons , need two sets of hands, or press them in with a clamp and a piece of plate,  brake grease on calipher seals,not to much may help,a lot  forget to unscrew the bleeder nipple , never had trouble with this with genuine seals  KDM  , take your time and make sure the pistons are square

this sounds like a great idea if they're being stubborn 

[Molly]

if your careful you can suck them in using a brake sucker on the nipple, but you have two pistons , need two sets of hands, or press them in with a clamp and a piece of plate,  brake grease on calipher seals,not to much may help,a lot  forget to unscrew the bleeder nipple , never had trouble with this with genuine seals  KDM  , take your time and make sure the pistons are square

this sounds like a great idea if they're being stubborn 

Took it all apart again to give it another go. Not a chance.... The pistons are never going past those seals. I reckon the seal kit (Cycle Pro LLC 19258M) is garbage.

[klammer76]

Not sure on the parts availability though

visit your local KTM Bike shop, they use Brembos and have all the seals, o rings and pucks you need

FSG, do you by chance have any KTM part numbers for the seals, o rings and pucks or what KTM bike to use as a reference? Would like to record them for future reference.

Thanks

[Molly]

Not sure on the parts availability though

visit your local KTM Bike shop, they use Brembos and have all the seals, o rings and pucks you need

FSG, do you by chance have any KTM part numbers for the seals, o rings and pucks or what KTM bike to use as a reference? Would like to record them for future reference.

Thanks

That'd be great actually. I emailed a couple of KTM dealers but they said they couldn't help. You have to assume that the pistons and seals aren't specific to the H-D badged Brembo. The only other reference I could find was to a Honda part but, as is often the case with forums, I found further comments to say it was misinformation.

I've stripped my calipers down again and will go into Christchurch tomorrow to trawl the bike dealers and try to find a parts guy that can help.

[klammer76]

Not sure on the parts availability though

visit your local KTM Bike shop, they use Brembos and have all the seals, o rings and pucks you need

FSG, do you by chance have any KTM part numbers for the seals, o rings and pucks or what KTM bike to use as a reference? Would like to record them for future reference.

Thanks

That'd be great actually. I emailed a couple of KTM dealers but they said they couldn't help. You have to assume that the pistons and seals aren't specific to the H-D badged Brembo. The only other reference I could find was to a Honda part but, as is often the case with forums, I found further comments to say it was misinformation.

I've stripped my calipers down again and will go into Christchurch tomorrow to trawl the bike dealers and try to find a parts guy that can help.

As I mentioned, when I did mine they were difficult also. Lube the o rings lightly then the piston lightly. get as square as you can then use a slight twist action. I think I went clockwise while adding pressure.

[-deuced-]

Honda part numbers in this thread

https://harleytechtalk.com/htt/index.php/topic,109413.msg1304420.html#msg1304420

[speedzter]

The Honda part numbers listed are to suit late 80's 250cc bikes, likely Nissin calipers, interesting.