CB360 Caliper

I have the classic seized caliper on my 360. I've done my research on getting these things out and plan on finding the 10mm X 1.25 pitch zerk fitting and a grease gun this afternoon when I head into the city. I've tried pushing the piston back in, to break it free, but I think it's bottomed out in the caliper.


I think it's going to be easier to get the piston out if I remove the pad first, instead of trying to push both of them with the grease.


By the way, I have already hooked it up to my master cyl. and I didn't budge.
And it has been soaking in mineral spirits for a couple of days.


My question is:


Is the piston hollow (cupped) directly behind the pad as most pistons are?


My idea is to drill through the pad, tap the steel behind the pad material, and see if I can pull/ wiggle the pad out.


You can see in the pic that I have already drilled through the pad material, and got to steel. I didn't want to drill through the piston so i stopped.


I've never seen the piston from this bike, and the schematics show it solid from the rear (brake fluid side, or inside the caliper housing), so I'm not sure if the piston is solid, or the "bottom of the cup" is inside the caliper or touching the brake pad.


I hope I didn't make this too confusing. Thanks for the help.





You can see that the pad is down there pretty good. And STUCK!

Do the zerk/grease thing before anything else. It applies much more pressure than the master cylinder.

The pad is permanently mounted to a metal plate. Then after that is a plastic washer and a solid steel piston that fits in the caliper cavity.

The pad slides back and forth only. You can't wiggle or twist it out.

The grease gun is simple and almost always pushes them out.

When you get the piston out clean it up with a brass wire brush wheel mounted in an electric drill or drill press to see if it's not too corroded to re-use.

Brake fluid is water soluble. Wear rubber gloves when messing with fluid so you skin doesnt soak it in and collect in your kidneys.

The piston is solid! I was afraid of that.

Yeah, I was hoping to tap that metal plate that's part of the pad, but off to harbor freight I guess.

I do plan on hitting it with the bernzo torch too. Maybe a little heat will help.

Struck out finding the grease fitting yesterday. They had the box for them at Ace Hardware, but it was empty. Checked all of the auto parts stores too. Probably order one from Fastenal tomorrow.

Posted my fix on your other thread bro may work for you, did fine for me.

The piston IS NOT SOLID
It has a pressed in cap.
Tapping it will probably pull the cap off without moving piston.
use grease fitting. (or, search my dangerous removal method, crazy but fun ;D )

What's that, light a fire under it and wait for w/e is in it to heat up and expand and then watch it blow 30-40 feet into the air? ;D And yes that is a joke although I did similar once with an old car caliper and a blow torch. Man dad was PISSED.

;D 8)
That's the way

PJ

crazypj said:

;D 8)
That's the way

PJ

Click to expand...

I LOL'ed so hard I about fell outa my chair. ;D

Well, Fastenal can't get the grease fitting I need. I also called around to every auto parts or industrial supply in the area, as well as looked around online.

I did have some other ideas, maybe someone who has had this thing apart can tell me if my ideas are flawed.

My idea is to drill a hole in the back center of the caliper housing.

Then either: 1. Tap the hole, thread in a long bolt and push the piston out of the housing with the bolt.

2. Tap the hole to the common 10mm x 1.00 grease fitting and push it out with grease. Then plug when done.

3. Simply tap the piston out from the back, through the hole with a big punch, then tap the hole and plug.

Like I said, I've never had one of these apart or have seen the insides, so if anyone can offer any insight that would be great.

Just PayPal me $5 for shipping and I'll send you the zerk unless you're really set on drilling and tapping something. :-X

I would really appreciate that. PM me your address.

Your grease zerk is on it's way, I sent an email earlier.

The piston will be nasty but use a brass wire brush wheel in your drill or drill press to clean it up and it will shine like new. If it's excessively pitted you'll have to replace it.

Brass is softer than steel which means a brass wire wheel won't damage/scratch the steel piston.

There will also be a rubber seal set in a groove in the caliper cavity. Use something pointed to remove it and clean the seal and the groove really good and you should be able to reuse that rubber seal. I've never had to replace one even when the piston was too far gone.

I got the grease fitting in the mail yesterday and was finally able to give it a shot. The grease fitting was not the correct thread, it was a 1.0 pitch as opposed to the correct 1.25 pitch. I wish I would have known that before, because the M10 x 1.0's are available just about anywhere, but I do appreciate the help from mitchellsk. So, using mitchellsk's advice, I just treaded it in until it began to cross thread, and went from there. I did boil the caliper for about 20min before I filled it with grease; and what do you know, it popped right out!


Ordinarilly I would not recommend intentionally cross threading anything, but if you're in this same situation, there aren't to many other alternatives. Like I said, just threading it in until it stopped threading was enough to do the trick.


All cleaned up.....





I cleaned the piston up with a brass wire wheel on the drill. You can see some pitting, but this was the worst of it. I think all in all it looks decent. At least not bad enough to spend $90 on a new one.





I ended up putting it all back together to test the whole system and it worked great. The o-ring was not in bad shape, but I will replace it for good measure next time I place an order.


Thanks for everyones advice.

Awesome, looks great man. Most stuff is easy once you know how. Help the next person with something when you get the opportunity.

kMoto said:

I got the grease fitting in the mail yesterday and was finally able to give it a shot. The grease fitting was not the correct thread, it was a 1.0 pitch as opposed to the correct 1.25 pitch. I wish I would have known that before, because the M10 x 1.0's are available just about anywhere, but I do appreciate the help from mitchellsk. So, using mitchellsk's advice, I just treaded it in until it began to cross thread, and went from there. I did boil the caliper for about 20min before I filled it with grease; and what do you know, it popped right out!


Ordinarilly I would not recommend intentionally cross threading anything, but if you're in this same situation, there aren't to many other alternatives. Like I said, just threading it in until it stopped threading was enough to do the trick.


All cleaned up.....

I cleaned the piston up with a brass wire wheel on the drill. You can see some pitting, but this was the worst of it. I think all in all it looks decent. At least not bad enough to spend $90 on a new one.

I ended up putting it all back together to test the whole system and it worked great. The o-ring was not in bad shape, but I will replace it for good measure next time I place an order.


Thanks for everyones advice.

Click to expand...

Hmm, I can't find the 1.25 pitch either. So just threading it a few threads worked?

I threaded it in until I could feel the resistance, and then just gave it a slight tweak with the wrench. Nothing more than that. My piston was pretty solid in there too. It pushed right out like it was nothing. I would recommend boiling it first though.

polish it... they look... sooo... pretty....