Brake Pad Replacement

[utadventure]

I replaced tires today on my '86 and need to do brakes next.

 

This is my question. Do you replace the pads with the calipers in place or do you remove them from the mount/rotors?

 

Dave

[Dano]

Pull the calipers to change the pads, you'll need a decent size c-clamp to push the pistons back in for new pads. Check the online service book available here on how to do it.

[Keemez]

Once the pads are out, if you've got a fair amount of strength in your hands you can actually force the pistons back in by (2x)thumb pressure. You gotta push pretty hard, but they'll go back in. Mine did, anyway.

[Snaggletooth]

Pull the calipers to change the pads, you'll need a decent size c-clamp to push the pistons back in for new pads. Check the online service book available here on how to do it.

 

 

Now I've got to bring up a question. This is pretty much SOP for most all the guys I know that do their own brakes on bikes and cars.

 

BUT....... I always crack the bleeder valve to let the fluid pressure blow off on that end rather than being forced backwards into the closed system. Without opening the bleeder you are forcing old and dirty brake fluid back into the lines, proportioning valve, master cylinders and reservoirs.

 

I see several benefits to this method.

 

1. No dirty fluid is forced backwards into the system. Small ports like in the masters are less likely to become plugged.

 

2. It takes less pressure to press the pistons back into the caliper bodies.

 

3. It does not create an excess amount of fluid being forced back into the reservoirs, which is known to cause problems on the rear brake from overheating and expanding causing the brakes to drag. If you have ever added fluid after running the brake pads for a while this can be an issue when the piston is fully retracted again.

 

I mean after all, you were planning on bleeding the brakes anyway right? Just to change out the old fluid for new? Why force the dirty fluid through twice?

 

Just a practice I have had for a long time. Always worked. Or am I just retentive?

 

Mike

Edited May 20, 2012 by Snaggletooth

[Dano]

Hmmm, been doing it this way, even on cars, since the 70's. MOST systems are setup with new brakes, calipers, pads (or shoes with drums) when they are built. Systems are filled with proper amount of fluid then. If you are replacing worn out pads, all you are doing is returning the fluid in the piston cup area a SHORT ways back up into the line. When pumped to set the pads against the rotor when done you are just placing the system back to where it was when it's new.

 

NOW, if you are replacing the fluid you release when you bleed it out the bleeder, then over time you are replacing all the fluid. This is a good way to accomplish what is hard to do if you replace all the fluid at once and want to prevent air bubbles getting in there. But you MUST watch that you're not mixing the wrong types of brake fluid!!

[Snaggletooth]

Hmmm, been doing it this way, even on cars, since the 70's. MOST systems are setup with new brakes, calipers, pads (or shoes with drums) when they are built. Systems are filled with proper amount of fluid then. If you are replacing worn out pads, all you are doing is returning the fluid in the piston cup area a SHORT ways back up into the line. When pumped to set the pads against the rotor when done you are just placing the system back to where it was when it's new.

 

NOW, if you are replacing the fluid you release when you bleed it out the bleeder, then over time you are replacing all the fluid. This is a good way to accomplish what is hard to do if you replace all the fluid at once and want to prevent air bubbles getting in there. But you MUST watch that you're not mixing the wrong types of brake fluid!!

 

 

I hear ya Dan. Old method done for a long time. It works, and it does save some effort in the long run. I was just wondering about the way I have been doing it.

 

In my case I drain out the master reservoirs every time I change pads and fill with new brake fluid through the system. At the same time I do the clutch system.

 

Ya know, you could have just said "You're retentive!" Saved some typing.

Later

 

Mike

[Dano]

Ya know, you could have just said "You're retentive!" Saved some typing.

 

 

:sign yeah that::sign yeah that::sign yeah that:

[greg_in_london]

Hmmmm.... "Wrong type of brake fluid" - this seems to be something that you all worry about over there, but we use the same stuff (or higher spec - some of you still use DOT3 for preference??) and have no problems assuming that it all mixes. I'm not sure if it's a legal requirement that they should all mix, a requirement of the standards or just something all the manufacturers say, but except for the silicon stuff some French cars use, it's all interchangeable. DOT3 just absorbs more water and boils at a lower temperature.

 

When I want to bleed brakes I often push the pistons back to help clear air out of the lines, but I wouldn't bother bleeding the brakes just to change the pads. That might be because I have to change the pads more often than once per year and the fluid does not age much in that time - and I use higher quality fluid than DOT3, so it picks up less moisture.

 

If the brakes aren't working right, I'll pump out each piston, clean off the crud and lubricate with red rubber grease, or bleed out the brakes with fresh fluid depending on the symptoms as necessary.

 

Then again, if I have to drive to the pub where I play music (1.1 miles according to Google) I have to go through ten sets of traffic lights, so I may be doing more stopping and starting than most...

[bongobobny]

I don't pull the calipers, just use a pry bar to spread the calipers before I take the old shoes out. I have used Mike's method but as stated you have to replace what comes out...

[greg_in_london]

Ditto - I forgot to say that. I'll only pull the calipers if I have to work on them - otherwise changing the pads is a quick job. In fact - if they're working well, it's a side of the road job and I leave some in the top box.

[Midicat]

Ditto - I forgot to say that. I'll only pull the calipers if I have to work on them - otherwise changing the pads is a quick job. In fact - if they're working well, it's a side of the road job and I leave some in the top box.

 

With all the great tech info here, clutch replacement, stator replacement etc, has anyone ever documented the steps (with photos) to replace brake pads for those of us who are handy with tools but aren't sure of the proper steps to follow? Just askin'.

 

Thomas

[Brake Pad]

Why do you want to replace me?

[Squidley]

Why do you want to replace me?

 

Because your old and worn out....just sayin

[videoarizona]

Actually, I think Mike has the right idea here. If you open the bleeders while you push back the pads, you are releasing the excess fluid you WILL have in your system with new pads installed. This is assuming you have kept the fluid levels up as the pads wear. If you don't release the fluids or remove some from the rear master cylinder...I can almost guarantee you will have too much fluid in the rear system, causing your brakes to start to bind as the fluid heats up while riding.

 

I never thought of opening the bleeders because of the mess or just plain lazy. Didn't want to dig out the lines and such to capture the fluid coming out of the bleeder. BUT, I always did use a towel or baster to remove the excess fluid from the master cylinders after replacing pads. At least I got that part right. BTW, using a small syringe or a rolled tip of a towel (wicking) is about the only way I know to remove excess fluid from the rear MC as the hole is so small! Using the bleeders makes so much more sense!

 

Thanks, Mike...simple thoughts I like!

 

 

[dna9656]

I have read to never add brake fluid to make up for brake pad wear for the very reason that there will be too much fluid in the system when it's time to change the pads.

Could it be the designers felt that if the fluid level is low enough to cause concern then it's time to change the pads? So far as contaminated fluid residing only in the caliper and getting pushed up to the master cylinder when pushing the cup back in to the caliper I donno.... you can't compress a fluid, first law of hydraulics...the fluid forms a column of force (confined by the hose/pipe) and pushes the cup out applying force to the brake pads, how would the fluid get stirred up when (essentially) the actual amount of travel the fluid takes is very small? Now if you got air in the system the bubbles certainly could cause the fluid to mix up with it self, carry contaminates to the rest of the system yes? So this opening the bleeder while you pry the cup back into the caliper, that could be tricky as you have to keep a bleeder hose under control while having the bleeder wrench in place simultaneously prying on the brake pads, a good trick or a 3 handed job...As difficult as it is to bleed the system on the early (unmodified) bikes (my only experience) I don't know if I'd want to risk sucking the air in this way versus just bleeding the brakes (with the bleeder hose under control) after the new pads are installed. I guess it boils down to your skills/equipment, having some help, or some sort of bleeding machine that applies brakes for you while you tend to the activities at the caliper. I know a lot of us are pretyy slick at this stuff and some of us are less so, and that's why we're all here! To share and learn!

[Karaboo]

I always thought the fluid should get flushed after a pad change, just to keep everything clean on the inside. Then you end up with the correct amount of fluid in the reservoir with the new pads in place.

[utadventure]

Because brake fluid is hygroscopic (absorbs water), it's recommended to change the fluid out regularly. Many here have mentioned every other year. Having old fluid, in the caliper only, shouldn't be a problem if you do this.

 

I usually use an eye dropper and remove the old fluid from the reservoir and refill with fresh then pump the fresh into the line and caliper. You shouldn't have any air issues as long as you keep enough in the reservoir as you go.

[Brake Pad]

I hope after the installs that you went with up graded Pads. I change mine out every year, and again, if I'm pulling the trailer on a long trip.

[flyday58]

With all the great tech info here, clutch replacement, stator replacement etc, has anyone ever documented the steps (with photos) to replace brake pads for those of us who are handy with tools but aren't sure of the proper steps to follow? Just askin'.

 

Thomas

Like for the tech library?

[Midicat]

Like for the tech library?

 

EXACTLY!!! I searched and couldn't find a thing here. Now, if I want to repair a second gear issue, it's here. Clutch - got it. Stator - got it. Fork seals - got it. Butler mod - got it. No brake pad replacement. Is it just too basic a project to be bothered with?

 

Thomas

[flyday58]

Actually I was just poking gentle fun about a thread I started concerning the tech library. For the most part it's pretty easy to find what you need on the site, just when I'm broke and want it fixed NOW I ain't got the patience to do it. As with your thread, you see there's different ideas about how to get the job done, all valid. So I reckon the place we all should start is Yamaha's manual, a great updated version of which is available here, then add our own touches from experience and from other site users.

 

Fr'instance, some folks came up with the notion on rear wheel removal, to remove the front wheel first, let the bike kneel on the forks, then drop the rear wheel. I wouldn't have ever thought of this, but it saves the aggravation and time of removing the seat and rear fenders to get enough clearance to get the rear wheel out. Works like a charm but I always did it the time-consuming way till reading that post. So it takes some time to find some of this stuff but it's all here.

 

If I only had ":guitarist 2:...just a little patience...:guitarist 2:" (thanks to Axl Rose)

[greg_in_london]

???

 

Or just have a block of wood to go under the centre stand. Don't try and lift it all in one go - put the bike on the centre stand, lean the bike one way and push the block under the stand on one side with the toe of your boot and then lean it the other way and kick the other end of the block under the other leg. You still have to take a silencer off though.

 

I won't say not to change your brake fluid, but DOT4 or later is good for a fair few years without changing it. It doesn't take long to do, but I doubt I'd be changing it every year.