Author Topic: front caliper rebuild cb500  (Read 9016 times)

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Offline flybox1

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Re: front caliper rebuild cb500
« Reply #25 on: June 16, 2015, 10:13:25 AM »
clean its mating surface.  might be some debris in there preventing a good seal.
also, you can put a rubber cap on it
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Offline Powderman

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Re: front caliper rebuild cb500
« Reply #26 on: June 16, 2015, 10:48:25 AM »
I did install the hollow piston the correct way, but it was the lack of thorough cleaning that caused it not to fit. When I cleand it with just the wire brush it basically polished the crud in the groove, making it look like it was clean. I went in there with some dental tools and got all that crud out, then did the wire brush. It should fit now.

The other problem is the speed bleeder won't stop bleeding, even when tightened down. Anybody ever put a small o-ring in there to make it seal better, or is that just crazy talk?
The bleeder seals by butting up against the end of it. Adding an o-ring would leave it that much further off the seat and not seal.

I meant something like this:


I don't think you would be able to tighten it enough to seal.

Offline jonda500

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Re: front caliper rebuild cb500
« Reply #27 on: June 16, 2015, 10:13:21 PM »
I fixed mine by fitting a new bleeder nipple.
You could try cleaning the seat of the bleeder hole in the caliper and polishing the sealing end of the nipple
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Offline Korven

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Re: front caliper rebuild cb500
« Reply #28 on: March 19, 2019, 12:40:30 PM »
open end goes OUT, towards the brake pad.

This Side out towards the pad?


Offline jaytee-nz

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Re: front caliper rebuild cb500
« Reply #29 on: March 19, 2019, 01:27:30 PM »
No, the hollow side of the piston goes to the back of the brake pad. The solid side (shown in your picture) goes in to the caliper body first.

Offline bryanj

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Re: front caliper rebuild cb500
« Reply #30 on: March 19, 2019, 01:33:41 PM »
That is the hollow side with a cinched in cap
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Offline Korven

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Re: front caliper rebuild cb500
« Reply #31 on: March 19, 2019, 01:40:19 PM »
No, the hollow side of the piston goes to the back of the brake pad. The solid side (shown in your picture) goes in to the caliper body first.


Sorry forgive my ignorance, but too me both sides are "Hollow" and the side i linked have the bigger depression. Maybe its lost in translation.

"having a space or cavity inside; not solid; empty: a hollow sphere. having a depression or concavity: a hollow surface. sunken"

Anyways guess i have it mounted the wrong way then (i was just looking at the exploded view and it showed no such surface)
One more time just so i dont mix it up again. When i remove the pad, the side i linked should not be showing?

Offline jaytee-nz

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Re: front caliper rebuild cb500
« Reply #32 on: March 19, 2019, 02:04:38 PM »
I see your point about both sides being hollow. Referring to your picture from CMSL, the end of the piston that is visible in the picture does has a small hollow in it. If you turn the piston around, the other end of it has a large hollow in it and effectively only the outside edge or rim of this end presses against the back side of the brake pad.
Hope that makes things more clear for you.

Offline Korven

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Re: front caliper rebuild cb500
« Reply #33 on: March 19, 2019, 02:35:15 PM »
I see your point about both sides being hollow. Referring to your picture from CMSL, the end of the piston that is visible in the picture does has a small hollow in it. If you turn the piston around, the other end of it has a large hollow in it and effectively only the outside edge or rim of this end presses against the back side of the brake pad.
Hope that makes things more clear for you.

So the piston shown in this video is mounted the wrong way? Seems like the same side i linked above showing when removing the pad.

Offline Stev-o

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Re: front caliper rebuild cb500
« Reply #34 on: March 19, 2019, 02:51:58 PM »
Thats a pretty good video but...

1. It's not a brake shoe!
2. I would not put the brake pad in a tub that is getting ready to have brake fluid spilled in it.
3. Vise grips on the bleeder valve....really?!  Use the right tool!  [closed end wrench works fine]
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Offline jaytee-nz

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Re: front caliper rebuild cb500
« Reply #35 on: March 19, 2019, 03:14:59 PM »
Yes, the piston in the video is the mounted wrong way.

Offline Korven

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Re: front caliper rebuild cb500
« Reply #36 on: March 20, 2019, 05:50:23 AM »
And so is mine :( hope i didn't damage the seal. How does one remove a dual caliper system? First one by braking and the second with air?

Offline bryanj

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Re: front caliper rebuild cb500
« Reply #37 on: March 20, 2019, 06:15:17 AM »
On a twin piston system remove a pad and pump the master till both pistons touch the disc then remove caliper and pump till one piston pops out and hope the other moves with grips. Or did you mean the type with one pistn each side of disc?
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Offline Korven

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Re: front caliper rebuild cb500
« Reply #38 on: March 20, 2019, 06:27:03 AM »
On a twin piston system remove a pad and pump the master till both pistons touch the disc then remove caliper and pump till one piston pops out and hope the other moves with grips. Or did you mean the type with one pistn each side of disc?

It's on a cb500 and uses the original calipers. There won't be any risk of getting brakefluid splashed everywhere when pumping the piston against the disc? It will stop beforehand?
Is it really safe to use gripson the piston?


The small tube of grease one gets with a master cylinder kit is that safe to use on the the caliper (on the seal, wet side) I bought the repair kit at dss for the master cylinder.
The plastic spacer that follows the brake pads seems to be missing. What kind of function do they have? Im getting new ones from dss but want to wait until i need something else before ordering since the shipping quote is about 20euros.
« Last Edit: March 20, 2019, 10:17:25 AM by Korven »

Offline Korven

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Re: front caliper rebuild cb500
« Reply #39 on: March 23, 2019, 10:41:46 AM »
Im still a little bit confused on what way the piston should be mounted. The honda shop manual shows it the "wrong" way. Why should it not be mounted that particular way. the edges are phased down on one side.




Offline robvangulik

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Re: front caliper rebuild cb500
« Reply #40 on: March 23, 2019, 11:48:59 AM »
The smooth side goes into the caliper, the last pic shows the front which pushes the brakepad.

Offline Korven

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Re: front caliper rebuild cb500
« Reply #41 on: March 23, 2019, 02:59:10 PM »
The smooth side goes into the caliper, the last pic shows the front which pushes the brakepad.

And that is exactly the opposite to how the people above tell how its done. Does anyone know for sure what way it is suppose to mount and for what reason?

Offline bryanj

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Re: front caliper rebuild cb500
« Reply #42 on: March 23, 2019, 03:09:16 PM »
The end that is solid metal, with or without a machined dimple, is the end that goes into the caliper, in your picture the other end looks solid BUT IT ISNT the hollow cavity is closed off by a cinched in plate so the piston is lighter.

As to the question about "twin piston" i think you really mean twin disc as twin piston to most mechanics means 2 pistons in one half of the caliper like most modern sports bikes.
On the standard 500 you just pump the master with the caliper in a suitable bucket untill the piston pops out, the instructions i gave for a twin piston are correct and as long as you only grip at the very end it will be above seal area anyway, plus if the pistons are that tight 99% of the time they are corroded and need replacing anyway.
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Offline Korven

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Re: front caliper rebuild cb500
« Reply #43 on: March 24, 2019, 12:00:02 AM »
The end that is solid metal, with or without a machined dimple, is the end that goes into the caliper, in your picture the other end looks solid BUT IT ISNT the hollow cavity is closed off by a cinched in plate so the piston is lighter.

As to the question about "twin piston" i think you really mean twin disc as twin piston to most mechanics means 2 pistons in one half of the caliper like most modern sports bikes.
On the standard 500 you just pump the master with the caliper in a suitable bucket untill the piston pops out, the instructions i gave for a twin piston are correct and as long as you only grip at the very end it will be above seal area anyway, plus if the pistons are that tight 99% of the time they are corroded and need replacing anyway.

Sorry, The solid and hollow side just get me really confused.  For some reason I have trouble separating the two.

Should It be mounted as show in the shop manual? Middle picture goes into the caliper. The end with the chamfer that is.

« Last Edit: March 24, 2019, 12:02:44 AM by Korven »

Offline bryanj

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Re: front caliper rebuild cb500
« Reply #44 on: March 24, 2019, 06:46:34 AM »
Simple answer YES
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!