Just changed the brake pads, all was ok before changing the pads except pads were down to almost metal. Anyway just put new pads in and the lever is spongy. Wasn't brilliantly firm before hand but easy one finger use. Now I have to use three as two fingers are in the way with the lever coming almost back to the bar. Is it just the heat or have I missed something? I'm not new to doing brakes and would just bleed them if I had had the system open, but I haven't . If anything I would have thought the brakes would be firmer due to the new pads. Or is it just because it is a hot day. Or is it just time to change the fluid?
Brakes spongy
- Thread starter Skudd
- Start date
Changing fluid is always a good idea, but pads also take time to bed in.
You did clean the discs too ?
Sent from my SM-G925F using Tapatalk
You did clean the discs too ?
Sent from my SM-G925F using Tapatalk
Put the bike on its side stand, turn the bars so the brake lever is at its highest.........cable tie the lever as tight as you can to the bar and leave over night.......see does it improve things.
Sent from a U11
Sent from a U11
This is what I have already done and playing the waiting game.
Operate the lever whilst observing the disk(s) very closely. Do the disk(s) flex sideways or stay centred?
An age old problem caused by pads having to travel a different distance either side of the disk before 'clamping' it, hence increased lever travel. EG inner pad is dominant, outer pad is lazy and has to travel further.
Usually evident with sticking pistons after a pad change, witnessed by the disk flexing sideways with excessive lever travel.
To solve it, jam a screwdriver between closer pad and disk face then pump brake lever to push furthest pad closer to disk. Once both pads are the same distance from the disk, you should find a firm lever with little travel to achieve clamping/braking effort.
I hope that makes sense.
An age old problem caused by pads having to travel a different distance either side of the disk before 'clamping' it, hence increased lever travel. EG inner pad is dominant, outer pad is lazy and has to travel further.
Usually evident with sticking pistons after a pad change, witnessed by the disk flexing sideways with excessive lever travel.
To solve it, jam a screwdriver between closer pad and disk face then pump brake lever to push furthest pad closer to disk. Once both pads are the same distance from the disk, you should find a firm lever with little travel to achieve clamping/braking effort.
I hope that makes sense.
NicD
Registered user
The symptom you describe sounds like air in the system. Could it have got in while changing pads?
btw when you cable tie the lever to grip, you don't need to apply a huge amount of pressure for it to be effective.
Personally I would bleed the system and see if any air came out of calipers or m/c. If so then would think problem will be fixed. If not, would revisit possible causes
btw when you cable tie the lever to grip, you don't need to apply a huge amount of pressure for it to be effective.
Personally I would bleed the system and see if any air came out of calipers or m/c. If so then would think problem will be fixed. If not, would revisit possible causes
He has only replaced the pads, not disturbed the hydraulics.
NicD
Registered user
That might be better formulated as a question.
If fluid not changed recently and pads run close to back plate, reservoir may have been very low - just one possibility.
In my view makes sense to eliminate most obvious cause of spongy lever. But that's just my view, and it is based on very limited info
It sounds more like the pistons may have been dirty and not cleaned before pushing them back in to make room for the new pads.
I would drop your calipers off their mount after removing the new pads. Then pump out the pistons a bit to clean them up before pushing them back in to refit. They could just be sticking in the calipers. Is there any drag on the pads when you spin the wheel on the stand.
I would drop your calipers off their mount after removing the new pads. Then pump out the pistons a bit to clean them up before pushing them back in to refit. They could just be sticking in the calipers. Is there any drag on the pads when you spin the wheel on the stand.
You say your old pads were neatly down to the metal .. in which case I suspect your discs are also worn. The new pads have a flat surface and your discs don’t. The contact area on the new pads won’t be as much as you’d pads, as on the old pads the two surfaces were worn together. You have to wait until the new pads have bedded in against the worn disc surface. Until then they’ll feel squashy/spongy as the pad material gets “squidged” 
Have done the cable tie thing and they have improved, but I think a piston clean and new fluid will be in order on my next day off. The bike stops well, just not as sharp as I like them.
As Steptoe has suggested, maybe they need time to bed into the discs which makes sense,
How many miles have you ridden on the new pads so far?
we don't know that ? if you push back 4 very worn pads to a fully topped up master cycling you have pushed far to much fluid back, so it may spill... or let it out elsewhere
heavily worn disc and cheap nasty pads will 1 ) take an age to bed in impacting lever feel, 2) naff pads will always give a nasty feel, 3) new fluid every few years is a good idea. When BM bleed the brakes it gets a very firm lever. I've swapped out the ABS11 module twice and tried to get all the air out but they seem to manage it better than I do.
Similar threads
