Caliper problem(excessive lever travel)

One of my front calipers has a problem I can't work out. If I squeeze the lever, the pads move out as expected, but when I release the lever, they go back in again instead of staying put! This means that there's a hell of a lot of travel on the lever before the brakes bite. What might cause this? It was doing it before I replaced the seals (one reason I changed the seals) and is still doing it afterwards.

Any ideas?

Did you lube the seals before fitting the pistons? Were the pistons clean/shiny or did they show signs of pitting or corrosion that the seal might stick on?

Tim.

[rictus01]

Sounds like the middle seal on your master cylinder are shot, this will mean the fluid will be both pushed and then pulled, busters sed to do service kits, not sure if they still do ?

Cheers Mark.

Originally Posted by rictus01

Sounds like the middle seal on your master cylinder are shot, this will mean the fluid will be both pushed and then pulled

Wouldn't I see the problem on both calipers? I wondered about seal orientation - the manual shows the seals having one edge deeper than the other and needing to go outwards. Damned if I could see any difference...

Originally Posted by I'm_a_Newbie

Did you lube the seals before fitting the pistons? Were the pistons clean/shiny or did they show signs of pitting or corrosion that the seal might stick on?

Seals were lubed before fitting, pistons lubed before insertion. The nastiness on the pistons came off with a brass wire brush.

[rictus01]

Sorry though you were talking about both (should spend more time reading original post ), and it should be evident on both although the pipe setup will have an effect (bridge pipe/twin line), indeed the seals should be fitted "the right way around" although I've not had your problem before (and yes I have fitted then the wrong way once), did you do both calipers the same ? has the line to the dodgy caliper been crushed/blown or something ?

Cheers Mark.

Originally Posted by rictus01

indeed the seals should be fitted "the right way around" has the line to the dodgy caliper been crushed/blown or something ?

I couldn't see there was any difference depth-wise between the two edges of the seals, so I just bunged them in whichever way they came out of the packet. They were Suzuki genuine parts too. I haven't had an 'incident' to any of the lines or calipers - that I'm aware of. I think I'll whip the offending caliper off again tomorrow and pop the pistons out again for another look.

SV calipers are not always rebuildable in my experience, rather than waste my time trying, I have just bought brand new calipers to begin with.

[Sid Squid]

Obviously you need to ensure that the seals aren't in some way dragging on the piston/s so thay don't retract excessively, but an often overlooked problem is the pins upon which the calipers slide, or possibly in this case don't. Check that the caliper bracket is completely free to move, if it isn't the problem you describe is sometimes the result.

Originally Posted by Sid Squid

Obviously you need to ensure that the seals aren't in some way dragging on the piston/s so thay don't retract excessively, but an often overlooked problem is the pins upon which the calipers slide, or possibly in this case don't. Check that the caliper bracket is completely free to move, if it isn't the problem you describe is sometimes the result.

What I would have said