Soft front brake lever after JUST changing brake pads (didnt bleed the brakes)

[Mate021]

Hey everyone. I found myself in a bit of a mess after changing the front brake pads. Is there anyone with experience than can point me to a right direction.


Problem is i have soft front brake lever right after changing the brake pads. Didnt remove calipers, didnt bleed the brakes, didnt open the brake cylinder cover. So brakes were ok one moment, and after 10 minutes, lever feels like theres a bunch of air stuck inside. No idea how i could have introduced air in the brakes. Is there something else i should consider?


R1200RT 2006 model, i was in a bit of a hurry so i just changed worn out brake pads, without removing the brake calipers. While the old pads were on, i gently separated them with a screwdriver, to push back the pistons. Replaced the brake pads, put back the metal clip, retaining screw, and the little hairclip. Important thing i gently retracted the pistons while NOT removing the brake cylinder cover, could that have done some damage possibly to the master cylinder or something else?

Appreciate any help guys!


edit important info, if i pump the brake several times, lever feels firm, than after i release, its soft again

edit typos

[sakm]

Carefully remove the reservoir cap and make sure its not over full

[Mate021]

It was over full, i removed exess fluid but still the same soft brake. Guess i need to bleed it to be sure

[David.]

Has the bike got servo brakes, does the situation change with the ignition switched on, pre-ride check completed and engine running.

[burridge01]

Try zip tying the lever up against the handlebar and leave overnight.

[Mate021]

Has the bike got servo brakes, does the situation change with the ignition switched on, pre-ride check completed and engine running.

No the bike had the "whizzy" servo removed, after it failed. About a year ago, i lost the rear brake while riding. Wasnt pleasant to realize i had almost 0% braking force on the rear wheel, but i count my lucky stars it wasnt the front brake...

Anyway, looks like the first thing to do is to bleed the brakes, and see is anything changes.

[Mate021]

Try zip tying the lever up against the handlebar and leave overnight.

ty, i had heared of that trick many years ago, but totally forgot about it. will do a proper bleed first though

[EasyRider]

ty, i had heared of that trick many years ago, but totally forgot about it. will do a proper bleed first though

As already said. I would zip-tie it over night before bleeding the system.

What has happened is, when you pushed the pistons back the rubber gators have moved on the piston. So when you pull the lever the pistons are pushed out but the gator stays where it is. Zip-tieing it over night will keep the pistons pushed out, but the gator will slid back down the piston over night to where it is relaxed. Its the gator that is pulling the piston back to far and giving you a soft lever.

[Mate021]

As already said. I would zip-tie it over night before bleeding the system.

What has happened is, when you pushed the pistons back the rubber gators have moved on the piston. So when you pull the lever the pistons are pushed out but the gator stays where it is. Zip-tieing it over night will keep the pistons pushed out, but the gator will slid back down the piston over night to where it is relaxed. Its the gator that is pulling the piston back to far and giving you a soft lever.

hmmm never even thought of that (not that i have any mechanical experience, but still :D )
ty m8 for taking the time to help! off to zip tie my brake

[EasyRider]

When i say "Gator" i mean the "dust seal" just so you know. It just the way i talk. it is only a small amount per piston, but it adds up.

[Mate021]

When i say "Gator" i mean the "dust seal" just so you know. It just the way i talk. it is only a small amount per piston, but it adds up.

yep, thats how i understood you. brake lever is zip tied, so fingers crossed tomorrow morning :D

[Mate021]

As already said. I would zip-tie it over night before bleeding the system.

What has happened is, when you pushed the pistons back the rubber gators have moved on the piston. So when you pull the lever the pistons are pushed out but the gator stays where it is. Zip-tieing it over night will keep the pistons pushed out, but the gator will slid back down the piston over night to where it is relaxed. Its the gator that is pulling the piston back to far and giving you a soft lever.

It worked ! ! ! After about 1.5 days zip tied, the lever is back to normal. Ty man, i love you!
i still need to work in the new pads, but the brake lever is ok.

I will bleed the system on the weekend, just to try to get a bit firmer lever, but this is great.

Massive TY to anyone that replied and gave an advice

[sakm]

That to me suggests the calipers could do with a rebuild and new seals

[Mate021]

That to me suggests the calipers could do with a rebuild and new seals

hey sakm can you please explain what concerns you. Is it that seals are damaged?
if i dont see any leaking, is that a sure signal brakes are ok, or would you still do the rebuild in my shoes?

[sakm]

The fact that the brakes have not pumped up straight away suggests the seals are gripping the pistons either from dirt on the pistons or dirt behind the seals

The pistons should slide nicely and smoothly