Binding front brake

[solemnwarning]

Story time...

The front wheel on my GS500 has been getting squeaky for a while, last week I replaced the front disc and pads since the disc was well past its service limit. Squeak still there.

Last night I stripped the caliper down, cleaned and greased the slide pins, cleaned out the hydraulic side and assembled with new seals, now I think its binding worse than before. Also fitted a new (HEL) hose, because no idea how old the previous one was.

If I apply the front brake and then let it off, the pads remain stuck against the disc hard enough that it turns for about 3/4 of a revolution before stopping. I'm pretty sure this isn't a (just) fault on the hydraulic side as when I ran it up and down the road with the pistons pushed fully in I'm sure I still heard a slight squeak.

The GS500 caliper has one slide pin in a blind bore in the body, the other in a through hole with a rubber boot wrapped all the way around it, the latter on mine isn't central and I have no idea if thats normal.

How freely should the caliper slide? Mine offers some resistance when inserted properly, no resistance if only the blind-hole pin is inserted, with the bracket clocked around 180° or so.

I'm not sure if the seals may be incorrect or badly made - I had to resort to a G clamp to get the pistons through them, don't think I've ever had to do that before.

Any suggestions what I should look at next?

Thanks

[kgm]

Pistons should be easy to push in by hand as long as they are square with the barrel. What condition are the pistons in? Did you clean the seal groves thoroughly? (I assume you have).

Master cylinder fault perhaps?

After a rebuild I find mine rub a little but it goes away quickly after I've used them a couple.of times.

[solemnwarning]

[Commuter_Tim]

Shit in the grooves is often the problem with sticky pistons, there is little room for play when it comes to distance from grooves-to seal-to piston, game of precision.

Did you clean out the master cylinder spring n stuff when you did the caliper?

I could be wrong, but are you sure you're supposed to sand pistons?
I've mostly read you shouldn't use anything to remove marks that is more abrasive than the piston surface.
As in, wood and plastic only.
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The above post is most likely nonsensical.

I ride a Bandit 600... badly.

[solemnwarning]

Definitely the wrong seals.

Popped the pistons out, each had cut/torn one of the seals into two pieces on its way in and left what was left twisted distorted in the groove.

Seal grooves in the caliper were immaculate, no dirt in them.

Off round the dealers tomorrow to try and get some seals.

Thanks for the replies.

[solemnwarning]

Well, two more sets of seals and I'm still no closer.

Apparently even official Suzuki dealers can't find the right seals for a the caliper on a 2004-2007 GS500. I had one who couldn't find the specs for the 2004+ model and sold me the earlier seals insisting they'd fit (they didn't).

So, based on the pistons and old seals, I /think/ the seals I need are as follows:

Seal A: 34.5mm (possibly 35mm) OD, 30mm ID, 2.5mm wide
Seal B: 34mm OD, 30mm ID, 2mm wide

Any recommendations for where I can get seals like this?

Thanks

[Kickstart]

Hiya

Wemoto lists a 30mm ID seal for the later GS500.

Earlier ones had different size pistons.

All the best

Katy
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[solemnwarning]

My first set of seals was from Wemoto, OD too large

[Paulf]

Fielders part give a part number perhaps you could use that for searching the web
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Past bikes simsom mofa 1s, suzuki hustler 250 (£35 in 1973), suzuki ts125k, mz150, yamaha yb 100, honda pc50, honda vision 50, all 2 stroke - then cars - honda pcx 125 (sold) own honda fes 125 and Mrs 125 spares or repairs. Started 1972 all accidents walked away no insurAnce claims

[solemnwarning]

[Paulf]

Fowlers dam predictive text
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Past bikes simsom mofa 1s, suzuki hustler 250 (£35 in 1973), suzuki ts125k, mz150, yamaha yb 100, honda pc50, honda vision 50, all 2 stroke - then cars - honda pcx 125 (sold) own honda fes 125 and Mrs 125 spares or repairs. Started 1972 all accidents walked away no insurAnce claims

[SQL]

pics of the caliper it may be from another bike

[solemnwarning]

The caliper is manufactured by AJP, looks identical to the other ones for sale like this one.

EDIT: Fowlers are in on the "Suzuki didn't make any GS500s after 2002" conspiracy it seems

[solemnwarning]

Looks like I won't be able to get the seals for this: linky.

Gonna try a few hydraulics suppliers after the bank holiday, failing that, get a different caliper I suppose...

Is this sort of shit normal for Suzuki? Never had this much trouble getting service items for /any other bike/. Not even ones from the 70s/80s that barely exist any more.

[solemnwarning]

Right, SV650* caliper rebuilt using the "GS500" seals (perfect match) and its still binding a little bit

Not as bad as before (wheel will do a couple of revolutions when span), but still enough for an annoying squeaking when moving.

auuuugh.

* purchased from a breakers since the seals/etc are still available