Front brake callipers - rebuild or replace?

[ManOfKent]

Hi,

I'm resurrecting a very low mileage '99 SV650 which stood idle for many, many years and have hit a snag with the front brakes. Once the seized pad retaining pins were out (blowtorch and Knippex pliers..) I could see the pistons were scabby with rust and the seals on some of them were protruding slightly and looking a little frayed. I'm guessing it was locked away wet and salty after it's first winter and not used again. Oh and it did spend a year or two under a cover behind a bloke's house - by the seaside if the state of the fasteners is anything to go by.

Anyhoo, connecting the callipers to a M/C I found they wouldn't come out any further and neither would they push back in. Now I'm sure I can get the pistons out, even if I have to heat them up and weld a strap across their mouths, but given that'll take me some time I haven't really got, plus I'm worried about the state of the bores, I wonder if there's suitable modern callipers I can buy off the shelf.

Any advice on the best purchase/home rebuild/send-away-for-rebuild route?
Thanks In Advance
Richard

[garynortheast]

I'd be inclined say rebuild them. New seals and stainless pistons and pins will do the job. The bores are likely to be fine, it'll be the bits exposed to the atmosphere that will be scabby. The standard calipers are more than up to the job of stopping the bike quickly as long as they are properly serviced. Stick some braided hoses on there while you're at it.

[Ruffy]

I'm with Gary - home rebuild is probably all you need. Decent pattern parts are plentiful and not stupidly expensive on ebay etc. (I've used Powerhouse in the past for seals and stainless pistons.)

Caliper bodies are alloy and seals usually keep corrosion to outside of the bores, so personally I'd be pretty confident that they'd be OK, needing just a deep clean once the pistons are out.

Alternatively, SV calipers are reasonably plentiful on secondhand market too (pointy are same as curvy) - though probably any secondhand purchase would warrant a service/strip & rebuild for confidence's sake.

AFAIK, calipers from different bikes generally require adapter plates or other mods, and would likely be a more expensive solution, so I'd be starting with OEM first if time is in short supply.

[Bibio]

if you dont feel confident then there are caliper rebuild services on the bay (for instance https://www.ebay.co.uk/itm/325324695...Bk9SR-DWmLzyYQ) that do it for £40-50 per calliper depending on state of pistons.

[admin]

I found the best way to get stuck pistons out of calipers is to blow them out with compressed air. I've even used a foot pump for this. I've seen some videos of people using a grease gun for really stubborn pistons.

Sent from my SM-T510 using Tapatalk

[mister c]

I agree with everybody else, rebuild is the way to go.
I had the scabbiest calipers I'd ever seen on my project & thought that I'd try compressed air, which failed, so then used a grease gun. I'd never tried this method before, but had heard that it was very successful, so thought why not? It worked brilliantly, the only issue I had was trying to get both of the pistons out at the same time as 1 moved faster than the other. I then cleaned the grease out of the calipers, cleaned them up & replaced the seals as the pistons weren't too bad at all.