brake caliper rebuild on the cheap?

[Jonzilla]

I went on a 20 mile ride yesterday on my still new to me 82 GS1100G. When I got home I noticed some oil splatters on the brake side of the rear tire. Upon closer inspections I could see it was leaking from the caliper. Dang.

Anyway so I looked online for a "rebuild kit" and found one for the rear that cost about 25-30 bucks. Then when I looked around again I saw that if I purchase the boot and piston seal individually it will only cost about 14 bucks.

In the experience of you who are more experienced than I, should these be the crucial parts that fix my leak? It seems that way to me. Though I've never rebuilt any calipers before.
Also I assume the pads are saturated with oil. Which is kind of a relief since I know this thing could probably stop better than it does right now. My front pads are soaked with fork oil and my rear is soaked with brake fluid. They are only barely used organic pads so if there's any method to cleaning that would be appreciated as well. I already tried brake cleaner, btw.

[hikermikem]

IMHO, use an OEM rebuild kit for th calipers. Those aftermarket ones (K&L) are not the best quality & may still leak...

The rear caliper has a small seal between the two halves of the caliper assy, perhaps that's the only thing leaking (if your lucky).

Good time to dis-assemble the entire rear brake system & clean it out while you are rebuilding the caliper - might want to rebuild the rear master cylinder too while you're there.

[Jonzilla]

Are you talking about the small o ring type piece? So I'm assuming the fluid has a port to flow between the 2 sides and that little seal it what holds it in. Right?

Can anyone point me to where to buy an OEM rebuild kit? I found places that sell the individual parts that claim to be OEM but searching for "rebuild kits" gets me a bunch of aftermarket stuff.

BTW if I still buy each part individually (2 boots, 2 piston seals and 1 little o ring seal) they are still a few bucks cheaper than the aftermarket "rebuild kits" I found.

[spyug]

The British have a saying , "Penny wise but pound foolish" which means scrimping on something to save money is not always the wisest move. In the case of brakes it definitely is not the wisest thing. Do not fool around with brakes. Find and use the OEM kits, your local suzuki dealer should be able to get them.

Pads cannot be salvaged once impregnated with oil junk them and replace when the calipers are rebuilt and your front fork seals replaced.Also be sure to clean off the disks with a grease cutting detergent and water.

I shuddered when I read that your front brakes are covered with fork oil too. You must have the stopping power of a bulk oil tanker. Definitely unsafe to the nth degree.

At this point, I would be rebuilding all calipers and master cyclinders as it sounds like they've never been serviced. Again don't take chances with brakes.....you never know when you will really need them.

Good luck .
spyug

[bwringer]

The OEM kits include a new piston, which you will need. Believe me, you will be astounded by the amount of crud and corrosion in there, and it's rare that a 25 year old brake caliper piston is something you'd want to use.

The aftermarket kits are shoddy junk and do not include a piston, and they are usually about the same price as the OEM kits. No contest, really.

Check online fiches at http://partshark.com and similar sites, or order through your friendly local Suzuki dealer.

[Jonzilla]

The British have a saying , "Penny wise but pound foolish" which means scrimping on something to save money is not always the wisest move. In the case of brakes it definitely is not the wisest thing. Do not fool around with brakes. Find and use the OEM kits, your local suzuki dealer should be able to get them.

Pads cannot be salvaged once impregnated with oil junk them and replace when the calipers are rebuilt and your front fork seals replaced.Also be sure to clean off the disks with a grease cutting detergent and water.

I shuddered when I read that your front brakes are covered with fork oil too. You must have the stopping power of a bulk oil tanker. Definitely unsafe to the nth degree.

At this point, I would be rebuilding all calipers and master cyclinders as it sounds like they've never been serviced. Again don't take chances with brakes.....you never know when you will really need them.

Good luck .
spyug

I'm all for not using aftermarket parts but I have only found indivual OEM parts and not the whole kit. That's why I'm asking about the individual




parts because they ARE OEM.

And yes, definitely scary with lack of stopping power. However, the only thing leaking up front is the fork seals. So after replacing them I will replace the front pads at the same time. Otherwise the new pads would get soaked too.

I only have had this bike for a week and I've ridden it 28 miles total all backroads. It actually does have the ability to stop but probably only 60% of what it should or could be.

Since I've located the parts that are OEM can someone confirm these are the correct seals? Parts 3,4, and 5:

[bwringer]

Yoicks -- it looks like part #1, the kit, is NLA.

#3, 4, and 5 are the seals you'll need.

If the pistons aren't re-usable, perhaps you can post in "parts wanted" for a rear caliper in somewhat better shape.

Is there an aftermarket source for brake caliper pistons?

[spyug]

Yup those are correct. I think, as our buddy says, you will also likely need pistons. It is highly likely, as he says that they are corroded and or even frozen in the bore. In the case of my Kat project, one of the rear pistons was frozen in place and I could not remove it and had to have a machine shop get it out. The bore was good but the piston was trash and needed replacing.

The pistons are hard chromed to resist corrosion but over the years if the fluids are not changed regularly, water remains in the system and rust starts to form. If the chrome cracks or deteriorates the rust can spread and if the piston doesn't move it can, over time, jam the piston in place.

When you pull the piston, you will find crap in the bores and maybe even damage to the bore walls. A small wire brush can ususally sort this. If the piston shows any cracking or pits in the chromed area it needs replacing. Do not reuse them as they can rust up again very quickly.

Over the last 7 years I've cleaned and rebuilt 15 calipers on bikes from the 70's and 80's. I have found crud in everyone and at least 6 with pistons that had to be junked. It is now SOP for me to tear down the brakes on any new to me bike. I just don't trust them being in good shape.

Once you clean and rebuild your brakes ( including master cyclinders don't forget) you need to get in the habit of changing the brake fluid regularly. Most manuals call for a change out every 2 years or so but I do mine at the end of each season prior to winter hibernation. If you get a Mity vacuum pump its a simple 10 minute job. Well worth it for peace of mind.

Good luck on the project.
Spyug

[Nessism]

If the rear is corroded and leaking it's likely the front has seen similar neglect. And while you are refreshing the system it's advisable to replace the brake lines at the same time (Suzuki calls for replacing them every two years).

[hikermikem]

Yoicks -- it looks like part #1, the kit, is NLA.

#3, 4, and 5 are the seals you'll need.

If the pistons aren't re-usable, perhaps you can post in "parts wanted" for a rear caliper in somewhat better shape.

Is there an aftermarket source for brake caliper pistons?

The OEM rebuild kit is still available for these rear calipers for around $30, and includes 2 pistons, 2 piston seals, 2 dust caps, 1 seal for the two caliper halves and a bleeder cap:

OEM PISTON SET - Suzuki P/N - 69100-34851

I get mine from PartShark, great prices but not the fastest shipping.

[hikermikem]

Are you talking about the small o ring type piece? So I'm assuming the fluid has a port to flow between the 2 sides and that little seal it what holds it in. Right?

you are correct...

[Nessism]

you are correct...

That seal is bullet proof and very unlikely to leak. It's nothing more than a flat O-ring trapped between the two caliper half's.

[hampshirehog]

As above buy original rubber bits - some of the pattern stuff is made of a substance more akin to party jelly than rubber.

For the pistons don't buy original; they rust, get pitted and leak. Buy stainless steel replacements. GSXR / RGV or pattern stainless all work. No need to fit the boots either. Some pistons don't have provision for boots - just replaced these on a GSX1100ET:

[Jonzilla]

I really like the idea of brand new parts. Somebody earlier said they discontinued the piston. It shows up on partshark as 30 bucks for 2 pistons. I sure hope they are still available!

I'm not sure which ones I would need. When I look up the parts for the 82 GS1100G it calls out 2 parts numbers for the piston set:
1-1PISTON SET
69100-34851 (replaces 69100-34810) 1$36.44$29.07 1-2PISTON SET
69100-34851 (replaces 69100-34820) 1$36.44$29.07

Edit^^ nevermind I clearly read that incorrectly.


Does that mean that either would work or what?

I still am going to wait to look at the piston before ordering, just wishful thinking. Make for sure I need them. I only need the rears right now too, btw. The front is functioning properly besides being lubed up real good by fork oil. I plan to change the fork seals and brake pads up there at the same time. And do the brake piston job in the rear and pads at the same time. The guy I bought the bike from (long time friend) flushed the brake lines just back in spring. But never got around to rebuilding the leaky forks or rear brake. They are downright dangerous how they are now. Plus the fluid that leaks drips on the tire. Nobody needs to oil their tire

[hikermikem]

I really like the idea of brand new parts. Somebody earlier said they discontinued the piston. It shows up on partshark as 30 bucks for 2 pistons. I sure hope they are still available!

I'm not sure which ones I would need. When I look up the parts for the 82 GS1100G it calls out 2 parts numbers for the piston set:
1-1PISTON SET
69100-34851 (replaces 69100-34810) 1$36.44$29.07 1-2PISTON SET
69100-34851 (replaces 69100-34820) 1$36.44$29.07

Edit^^ nevermind I clearly read that incorrectly.


Does that mean that either would work or what?

See post #10 - the piston sets are the same, Suzuki uses them on loads of their GS rear calipers...

In fact, I am in the process of using the same set on my '81 GS1100E. I initially re-used the pistons & seals when i took it all apart to clean thinking everything looked very good...however, I have now discovered it's leaking & like yours is depositing brake fluid on my tire sidewall & pads.

Even though the pistons looked good, I should have replaced all the componets when it was apart - I'll not make that mistake again.