What on earth is going on with caliper rebuild part numbers (81' 650L)

[DrewGS]

I've been looking all over tonight for a front caliper rebuild kit, and there seems to be a lot of conflicting information out there.

Some examples that sellers are offering:
- rear kits only for my bike - no front at all (many stores)
- listing all 650 models as using the same kit (doesn't seem to agree with the fiche)
- listing a K&L kit that will work for the front *or* the rear (doesn't seem right)

Searching alpha-sports and using their cross-reference tool, I spent way too much time creating a table with various options for buying the 2 boots, the piston boot, and the piston seal. From what I can tell, all three parts are shared between my bike and 1980-1982 550L. However, when I find kits for 550L, they say they aren't compatible with my bike.

I was going to just pay the extra $ and buy the parts individually from alpha, but I got concerned that one of the part numbers was one digit off of what was listed at Partzilla. I'm more cautious after ending up with the wrong head gasket recently from what seems to have been a mid-year change during the production of the '81 model.

I'm not asking someone to look anything up for me, but I'm curious...is this just how it goes when you buy caliper kits, or am I way over-thinking?

[Nessism]

https://www.brakecrafters.com/collections/1981-suzuki-gs650gl

These guys are reputable. K&L brake system parts are a crap shoot. A lot of them are poor quality and/or not well designed.

The rear seals are still available from OEM sources like Partzilla. I'd order them there and pray that your pistons are okay, because Suzuki doesn't stock them anymore.

[DrewGS]

https://www.brakecrafters.com/collec...suzuki-gs650gl

These guys are reputable. K&L brake system parts are a crap shoot. A lot of them are poor quality and/or not well designed.

Good to know. I did find that one, but it also seems to be a listing for G (which i thought was different). I sent them a note last night since they also have a kit with just the rubber parts for a 550L which might work based on the alpha-sports tool.

Taking apart the rear caliper tonight...

[DrewGS]

https://www.brakecrafters.com/collec...suzuki-gs650gl
...pray that your pistons are okay, because Suzuki doesn't stock them anymore.

Well, the rear brakes were...interesting. Based on these photos, would you reuse or replace? The insides of the pistons are terrible, but I figured that wasn't a problem, and I planned to carefully use a dremel on those (and only on the inside). I did find one source for pistons...it's in Japan and wouldn't arrive until March. Either that, or I take a chance on used ebay calipers and hope the pistons aren't as bad or worse.

[Nessism]

As long as there isn't any pitting on the sweep area of the seal, you are good to go.

[Gorminrider]

yes, (per Nessism) but that doesn't look good. As the pads wear, corrosion moves down the piston as more of it is exposed so if you put new pads in, that corrosion might (will likely?) be pushed down to the seals... you might get away with it if the corrosion is slight and you can polish it off or maybe in desperation, get some jbweld carefully filling the pits, which is just an idea i haven't tried.

You could try emailing ebay sellers. They might send you better pictures.

Apparently there are ways to fix pitted hydraulic rams -a similar problem. You might want to explore that because I bet a piston might be hard to find or very expensive.

[sacruickshank]

I was also in brake mode today on my '83 650L. Rears needed new pistons, but I fortunately had a factory rebuild kit stashed away from a 550T project that's been on hiatus for longer than I care to admit. The 650 is in better overall condition, so it gets first dibs on the fresh parts.


I got lucky on the front. With 12k miles on the clock the pads had very little wear and the piston was unblemished at 1/2 way out point. I suspect some previous owner replaced the pads and piston earlier in it's life, so I opted to simply push it back in. I know it's a short cut, but it seemed like low risk and easily fixed later if needed.
PXL_20220219_183307533.jpg

[DrewGS]

That's good you had those factory pistons on hand! After lots of searching I eventually found new rear pistons, but they weren't cheap. My brakes were a mess overall with rusty parts, etc. Hope I can get the bike running, or I may have brake parts for sale

Now I'm alternating between wanting spring to hurry up and get here and for it to hold off, so I can finish work on the GS and get some preventative maintenance done on my 'Strom in time for riding season.