Topic: front caliper rebuild cb500

[tennesseebreeze]

I'm about to put together my rebuilt brake caliper and master cylinder. Anybody have any tips on how to put it together without damaging the rubber parts? I'm afraid if I put it together dry it might scrape up the rubber parts. Do you coat the seals with anything to make it easier?

[tennesseebreeze]

Oh, I also need to replace my brake lines with braided. There are a lot of sources, but I haven't seen affordable ones that include a lower brake line with the fitting that goes into the standard hard line before the caliper. Any sources for this kind of thing?

[DaveBarbier]

Either use brake fluid or brake assembly fluid.

Slingshot-cycles.com

He's a member here and has great products. Forum members get a discount.


---
1978 Honda CB550K

[tennesseebreeze]

Awesome, thanks.

[DaveBarbier]

Hmm, they seems to be away at the moment. I'm pretty sure his username is Pampadori, maybe you can shoot him a PM. He might be able to give you an ETA of the site.


---
1978 Honda CB550K

[tennesseebreeze]

Hmm, they seems to be away at the moment. I'm pretty sure his username is Pampadori, maybe you can shoot him a PM. He might be able to give you an ETA of the site.


---
1978 Honda CB550K

Yeah I saw they were closed. I'm going to hit him up soon for those braided lines. In the meantime, I'm going to run the OEM lines and upgrade later. I'm anxious to get this thing on the road.

[flybox1]

read this before you assemble anything...

http://forums.sohc4.net/index.php/topic,56544.0.html

This thread has gotten very confused.  Lets' review.
There are four products needed to restore a caliper.
1. Brake cleaner
2. Brake parts assembly lube for the caliper seal only.
3. Dow corning High vacuum grease.
4. Brake fluid

Each has it own specific application and needs for the task to be performed.

#1 is used to get everything clean.  (given the confusion, it had to be said)
#2 is used ONLY on the seal and must be compatible with #4, as some of it will invade the brake fluid chamber.
#3 is NOT used on the seal, as that would put silicone inside the brake fluid chamber.  This is a bad thing as the compounds are incompatible.  It is used behind the brake pads and a thin coat is used on the parts of the calipers and piston that are exposed to the elements and subject to water ingression.  The Dow Grease will not mix with ANYTHING.  It is a simple barrier with the very important property that it will NOT melt when the parts get hot and then run/creep into the brake pad friction material and provide lubrication between pad and disk rotor.
#4 is what makes the hydraulic part of the brake function. (I hope that part is clear.)

The "Permatex® Counterman’s Choice® Ultra Disc Brake Lube" I have NOT used.
It is NOT to be used in the #2 application (directly on the caliper seal, as that would put some inside the brake fluid vessel and is clearly NOT it's intended application).

Depending on it actual composition, it may be suitable for the #3 task, IF and I stress the IF part, it will not melt/run into the brake pads.  The brake pads/rotor interface are where you WANT fiction!

Previous discussions in this forum were regarding Syl-Glyde, which I have personally tested and can pretty much guarantee that it will run/creep into the pad to rotor interface.  It only contains silicone as a minor ingredient.  The rest of this (Syl-Glyde) compound cannot take the 500F plus heat that the Dow corning grease can without doing a phase change.

The remaining question is whether Permatex® Counterman’s Choice® Ultra Disc Brake Lube will run/creep into the brake pads/rotor, especially when it gets hot, in this application on the Honda brake caliper.
I don't have any, I haven't tested it, you use it at your own risk.  I do know the Dow corning silicone grease DOES work properly and certainly appears to be the same stuff Honda used during production assembly.
I admit I am skeptical.  The last time a counterman recommended a product for #3 application, it was Syl-Glyde which, if he were still working behind the counter, I'd be tempted to make him eat.

[tennesseebreeze]

read this before you assemble anything...

http://forums.sohc4.net/index.php/topic,56544.0.html

This thread has gotten very confused.  Lets' review.
There are four products needed to restore a caliper.
1. Brake cleaner
2. Brake parts assembly lube for the caliper seal only.
3. Dow corning High vacuum grease.
4. Brake fluid

Each has it own specific application and needs for the task to be performed.

#1 is used to get everything clean.  (given the confusion, it had to be said)
#2 is used ONLY on the seal and must be compatible with #4, as some of it will invade the brake fluid chamber.
#3 is NOT used on the seal, as that would put silicone inside the brake fluid chamber.  This is a bad thing as the compounds are incompatible.  It is used behind the brake pads and a thin coat is used on the parts of the calipers and piston that are exposed to the elements and subject to water ingression.  The Dow Grease will not mix with ANYTHING.  It is a simple barrier with the very important property that it will NOT melt when the parts get hot and then run/creep into the brake pad friction material and provide lubrication between pad and disk rotor.
#4 is what makes the hydraulic part of the brake function. (I hope that part is clear.)

The "Permatex® Counterman’s Choice® Ultra Disc Brake Lube" I have NOT used.
It is NOT to be used in the #2 application (directly on the caliper seal, as that would put some inside the brake fluid vessel and is clearly NOT it's intended application).

Depending on it actual composition, it may be suitable for the #3 task, IF and I stress the IF part, it will not melt/run into the brake pads.  The brake pads/rotor interface are where you WANT fiction!

Previous discussions in this forum were regarding Syl-Glyde, which I have personally tested and can pretty much guarantee that it will run/creep into the pad to rotor interface.  It only contains silicone as a minor ingredient.  The rest of this (Syl-Glyde) compound cannot take the 500F plus heat that the Dow corning grease can without doing a phase change.

The remaining question is whether Permatex® Counterman’s Choice® Ultra Disc Brake Lube will run/creep into the brake pads/rotor, especially when it gets hot, in this application on the Honda brake caliper.
I don't have any, I haven't tested it, you use it at your own risk.  I do know the Dow corning silicone grease DOES work properly and certainly appears to be the same stuff Honda used during production assembly.
I admit I am skeptical.  The last time a counterman recommended a product for #3 application, it was Syl-Glyde which, if he were still working behind the counter, I'd be tempted to make him eat.

Great information. Thank you.

I've got another query- I'm replacing the the stock piston (steel with chrome coating that was totally rusted) with a machined stainless steel one. The original was solid and the new on is hollow with one side open. I'm assuming I face the open end toward the inside of the caliper and the closed end toward the pad. The pad has a convex surface on the back that I assume is so it has some self-adjusting play in it, preventing one side of the pad wearing faster than another. I wonder if the hollow piston will give me any trouble besides the amount of fluid needed in the system.

[flybox1]

open end goes OUT, towards the brake pad.

[tennesseebreeze]

open end goes OUT, towards the brake pad.

Okay, glad I asked that one!

[flybox1]

If you keep your stationary pad properly gapped, the pads should wear evenly.

[tennesseebreeze]

Well here is a little update about my front brake rebuild. I got the whole system together after rebuilding the master cylinder and caliper. I had the most trouble putting together the caliper. I assembled it with a new piston, seal, speed bleeder, and hard line. Trying to get the piston in was a #$%*. After greasing the seal with some dot-3 it still would not go in. The c-clamp would push the piston crooked in the caliper and it would get stuck- no matter how careful I was. I tried hammering it in with a wood block, and it would not go. It would just bounce against the seal and come out again. I took a wooden axe handle and pressed my weight on it, rocking it back and forth. This seamed like the best method and finally the piston went in. However, after getting it together and putting the fluid in and bleeding it, the caliper began to leak. I took it apart again and this was what i found- I had torn the seal trying to get it in. How the hell do you get this together without tearing it up?

[tennesseebreeze]

And another thing- the newly rebuilt master cylinder may be leaking a little. I won't know for sure until I fill it again. The dude at my local shop said master cylinder rebuilds fail 9 out of 10 times. Is that how they usually fail? Leaks?

[heyitsrama]

And another thing- the newly rebuilt master cylinder may be leaking a little. I won't know for sure until I fill it again. The dude at my local shop said master cylinder rebuilds fail 9 out of 10 times. Is that how they usually fail? Leaks?

i heard that 60% of the time they work overtime. but man i hope it does not fail. I would be so upset.

read this before you assemble anything...

http://forums.sohc4.net/index.php/topic,56544.0.html

This thread has gotten very confused.  Lets' review.
There are four products needed to restore a caliper.
1. Brake cleaner
2. Brake parts assembly lube for the caliper seal only.
3. Dow corning High vacuum grease.
4. Brake fluid

Each has it own specific application and needs for the task to be performed.

#1 is used to get everything clean.  (given the confusion, it had to be said)
#2 is used ONLY on the seal and must be compatible with #4, as some of it will invade the brake fluid chamber.
#3 is NOT used on the seal, as that would put silicone inside the brake fluid chamber.  This is a bad thing as the compounds are incompatible.  It is used behind the brake pads and a thin coat is used on the parts of the calipers and piston that are exposed to the elements and subject to water ingression.  The Dow Grease will not mix with ANYTHING.  It is a simple barrier with the very important property that it will NOT melt when the parts get hot and then run/creep into the brake pad friction material and provide lubrication between pad and disk rotor.
#4 is what makes the hydraulic part of the brake function. (I hope that part is clear.)

The "Permatex® Counterman’s Choice® Ultra Disc Brake Lube" I have NOT used.
It is NOT to be used in the #2 application (directly on the caliper seal, as that would put some inside the brake fluid vessel and is clearly NOT it's intended application).

Depending on it actual composition, it may be suitable for the #3 task, IF and I stress the IF part, it will not melt/run into the brake pads.  The brake pads/rotor interface are where you WANT fiction!

Previous discussions in this forum were regarding Syl-Glyde, which I have personally tested and can pretty much guarantee that it will run/creep into the pad to rotor interface.  It only contains silicone as a minor ingredient.  The rest of this (Syl-Glyde) compound cannot take the 500F plus heat that the Dow corning grease can without doing a phase change.

The remaining question is whether Permatex® Counterman’s Choice® Ultra Disc Brake Lube will run/creep into the brake pads/rotor, especially when it gets hot, in this application on the Honda brake caliper.
I don't have any, I haven't tested it, you use it at your own risk.  I do know the Dow corning silicone grease DOES work properly and certainly appears to be the same stuff Honda used during production assembly.
I admit I am skeptical.  The last time a counterman recommended a product for #3 application, it was Syl-Glyde which, if he were still working behind the counter, I'd be tempted to make him eat.

Great information. Thank you.

I've got another query- I'm replacing the the stock piston (steel with chrome coating that was totally rusted) with a machined stainless steel one. The original was solid and the new on is hollow with one side open. I'm assuming I face the open end toward the inside of the caliper and the closed end toward the pad. The pad has a convex surface on the back that I assume is so it has some self-adjusting play in it, preventing one side of the pad wearing faster than another. I wonder if the hollow piston will give me any trouble besides the amount of fluid needed in the system.

did you already get the SS piston? Doesn't SS react with aluminum? I went with a phenolic piston for that reason.

[chewbacca5000]

If the piston don't fit you must aquit!  Just kidding could not help myself.  Chances are there is crusty brake fluid in the seal grove.  It is hard to see it to get it all.  I use a bamboos stick like a large toothpick to get the crystallized fluid out.

Lube up the seal with brake fluid, fill the caliper up with brake fluid reinstall the piston.  Should go in a-ok this time.



 

[Stev-o]

I'm in process of a caliper rebuild.  After disassembly, the interior of the caliper must be spotless, especially the groove.  The piston must also be clean and not pitted (I realize you have a new one).
After both are clean, I test fit the piston in the caliper WITHOUT the seal, it should slide in with some pressure and also pull out too.

Try test fitting your ss piston, I have a feeling it is too big.

[wowbagger]

May also need to have the piston bore honed if it's in rough shape.

[tennesseebreeze]

The piston slides in fine without the seal. With a tiny bit of play. I measured the diameter with calipers and it is to spec. As far as the groove- I cleaned it pretty thoroughly with a dremel and a brass brush wheel. I'll get in there with a mirror next time. The speed bleeder not sealing is kind of a mystery though.

[Powderman]

You should be able to push the piston in past the well lubed seal with nothing more than the pressure of your 2 thumbs pushing it in.
Whether steel and aluminum are incompatible doesn't matter as nothing but the rubber seal and the back of the pad should touch the piston.
There should be no pressure to installing a piston with no seal, it should slide easily in and out.

[jamesbekman]

Yea you need to hone the caliper.  Its cheap and easy to do. 

[Powderman]

Yea you need to hone the caliper.  Its cheap and easy to do. 

If the piston slides in and out with ease why is honing necessary? There's nothing that moves against the bore to wear on it.

[flybox1]

You should be able to push the piston in last the well lubed seal with nothing more than the pressure of your 2 thumbs pushing it in.
Whether steel and aluminum are incompatible doesn't matter as nothing but the rubber seal and the back of the pad should touch the piston.
There should be no pressure to installing a piston with no seal, it should slide easily in and out.

absolutely.
with the newer, hollow pistons, i've seen some try and install these with the hollow end in the caliper bore, which is backwards.
when done this way the sharper edges of the piston edge can catch on the caliper piston seal, tearing it in the manner pictured above.
the closed end of the piston, with beveled edges needs to be inserted into the piston bore.  the beveled edges allow it to slide bast the seal quite easily, and take up all that extra fluid space in the caliper.

[tennesseebreeze]

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?

[Powderman]

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.

[tennesseebreeze]

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: