Topic: Front brake piston stuck.... any tips?

[SDmtnbkr]

The bike was having some serious braking issues and the front brake would lock up when the bike was turned off. So I pulled everything apart and it was a mess!! It was a bear getting the damn pad out, nor the piston is just dead stuck in there. Blasted the hell out of it with brake cleaner and wd-40 but it won't budge. Don't wanna try to grab it with pliers cause I'm sure it will ruin it. Anyone have any tips on how to get it out??

[SDmtnbkr]

 Never mind.  I just pump the break up really hard and it  shot out. Made a huge mess but at least it's out haha

[754]

Grease gun with adapter. Gets them out usually.. I made my own.
 You might be able to buy a bolt and thread. The head for a grease nipple
 Sometimes the greasegun with tip unscrewed fits pretty good with Teflon tape.

My buddy tried to pump one out last week and burst the brake line..

[SDmtnbkr]

Grease gun with adapter. Gets them out usually.. I made my own.
 You might be able to buy a bolt and thread. The head for a grease nipple
 Sometimes the greasegun with tip unscrewed fits pretty good with Teflon tape.

My buddy tried to pump one out last week and burst the brake line..

Thanks for the tip, I'll try that next time. ...was definitely worried about the brake line, but it held.

[PeWe]

use of compressed air in to the hose connection  will say POP!  you'll need to find where the piston landed.. 
....how do I know ?

[strynboen]

a mess to find your fingers tips.... after the POP...

[ekpent]

  You have probably found your problem but if the pads were locking up while you were riding and or using the front brake also make sure the return hole on the master cylinder is clear.  Also when you clean the caliper be sure to remove the rubber piston seal (cheap to replace with new) and make sure you get all of the white residue build up out of the groove. A Dremel with a soft wire brush makes quick work of it. Sure other will chime in with other tips.

[DaveBarbier]

  You have probably found your problem but if the pads were locking up while you were riding and or using the front brake also make sure the return hole on the master cylinder is clear.  Also when you clean the caliper be sure to remove the rubber piston seal (cheap to replace with new) and make sure you get all of the white residue build up out of the groove. A Dremel with a soft wire brush makes quick work of it. Sure other will chime in with other tips.

Brass wire wheel on a dremel and a dental mirror is the greatest pair of tools for cleaning that groove out! Makes quick work of it, doesn't harm the aluminum and you can get every last speck out.

I'll also recommend a phenolic piston from Godffery's Garage. Won't ever corrode and a great heat insulator.

[Phinn]

+1 on the phenolic. And a new seal isn't just for holding fluid in. It's an integral, functioning part of the braking system. If it doesn't grip the piston, deform under pressure and then return to normal shape when released, the brake won't work properly. A fresh seal in a clean groove will provide the needed elasticity.

Also, if your piston is frozen, the caliper arm is also probably stuck. Take it off, pull the pivot pin out and re-grease it. The arm must swing freely left and right on that pivot pin on order for the system to work, but the pin gets rusty so easily, being rarely moved and located so close to the ground.

[el pachuco]

a mess to find your fingers tips.... after the POP...

Turn the caliper half, face down on the work bench while applying the air.

[SDmtnbkr]

  You have probably found your problem but if the pads were locking up while you were riding and or using the front brake also make sure the return hole on the master cylinder is clear.  Also when you clean the caliper be sure to remove the rubber piston seal (cheap to replace with new) and make sure you get all of the white residue build up out of the groove. A Dremel with a soft wire brush makes quick work of it. Sure other will chime in with other tips.

Thanks for the tips everyone! Yeah I got it all apart yesterday and cleaned everything really good. I did pull the rubber seal and cleaned the groove but not to the level everyone is recommending so I will pick up a brass wheel tonight and make sure all the white residue is gone before rebuilding the caliper. My issue was that the piston was just corroded into place. Do I need to grease everything up when I put it back together?

I was definitely planning on getting a new rubber seal, but was wondering where you all get your OEM replacement parts? I also need a new bleed valve (old one is extremely corroded), new pads and some good grease.

[Phinn]

If the piston is corroded, it definitely needs to be replaced.  They corrode right at the spot where the seal grabs it, and that's the spot that needs to be smooth in order for the piston to move the tiny distance back and forth, to brake and release. 

4into1 sells OEM seals, I believe, through its own store and the [large online auction website] shop. Lots of places do. VinMoto and Power Barn sell the phenolic pistons.

I didn't grease mine up, and it works great.  The piston should be a tight but smooth dry-fit.  Some people suggest lubing the seal with brake fluid when assembling, but I don't see the point. 

And the pads should be free-moving when dry-fitted into place.  I had to sand the metal edge of the pad until it was smooth (and paint-free) to get it to fit properly, without binding.

[DaveBarbier]

Do I need to grease everything up when I put it back together?

Read this topic, but specifically the post by Two Tired that is directly linked. http://forums.sohc4.net/index.php/topic,104349.msg1215995.html#msg1215995

Brakes are very important and you want to do it right from the beginning.

-Edit-

As far as getting OEM parts: What I do is look my bike up on CMSNL.com and check the microfiche for the parts in looking for. It'll list the part number and then I copy and paste the number into eBay with "Honda" in front of it. "Honda xxx-xxx-xxx" for example. Then buy the cheapest one from what seems a reputable place

[SDmtnbkr]

Do I need to grease everything up when I put it back together?

Read this topic, but specifically the post by Two Tired that is directly linked. http://forums.sohc4.net/index.php/topic,104349.msg1215995.html#msg1215995

Brakes are very important and you want to do it right from the beginning.

-Edit-

As far as getting OEM parts: What I do is look my bike up on CMSNL.com and check the microfiche for the parts in looking for. It'll list the part number and then I copy and paste the number into eBay with "Honda" in front of it. "Honda xxx-xxx-xxx" for example. Then buy the cheapest one from what seems a reputable place

Oh wow, thanks a ton for that link to grease discussion, I didn't realize the process was so specific! Looks like I'll be ordering some Dow Corning grease. My poor wallet never gets a break, these easy jobs always seem to nickel & dime me. I'll definitely try out your parts acquiring method as well.

[DaveBarbier]

Glad to help. Member Two Tired doesn't show his face around here anymore, but there's some great info he's posted on all types of topics. I have probably a dozen links bookmarked from him that I refer to regularly, haha.

Good luck

[brewsky]

a mess to find your fingers tips.... after the POP...

+1
Part of mine were still on the (dual piston) caliper after it dropped!
I guess was holding the wrong piston!
Grease gun is the safe way to go and NO DRAMA!
A grease fitting will fit right in the bleeder hole, and a bolt in the inlet hole.

[strynboen]

yes ..on dual piston calipers..you must take it piece for piece..hold one piston ,,press aut .and block it and thange to the other...to get them so far aut they can be" lirked" aut