Front Brake Dragging Fix Attempt (Uh oh, that's not good)

[harfooz]

The title and description pretty much describe it all. I have an '05 non-ABS, and the front tire needed replacing. I got the wheel removed and got a Michelin Pilot Road 3 installed. When I came home to get the wheel back into the bike, the front brakes seemed like they were dragging...a lot. I don't have anything to compare to, however, because when I got the bike's front end raised to remove the wheel in the first place, I didn't spin it to see how much drag there was.

I removed the calipers from the rotors again and then removed the pads on the rider's left side. Thinking I'd clean the pistons with some brake cleaner, I asked my daughter to pump the brake lever to push up the pistons. What happened next was an eruption of brake fluid. Once I settled down, I cleaned the piston that popped out with brake cleaner (only one came out, and the other was raised slightly, while the two pistons on the other side didn't appear to move much at all -- if any), cleaned the caliper, and reinstalled the caliper on the rotor. Then I opened the reservoir, added fluid and proceeded to bleed the brakes. A lot of air came out. Eventually I got it to stop bubbling and topped off the reservoir. There is still a good bit of brake drag. I can get the wheel to spin about a half-turn before stopping due to the brake drag. I have taken care that the wheel axle spacers are on properly (the large spacer on the rider's left side). I've torqued each fastener to spec with a torque wrench.

Is there anything I'm forgetting about that would cause this much brake rubbing, or is this dragging normal?

I didn't bleed the rider's right front side -- it seems to be working fine and the brake lever feels solid -- although I think there is some dragging there too. Do I need to go back and bleed this one too, or is the air I introduced all out of it since there were no bubbles coming out from the left caliper?

Did I do any damage to anything in this goof of mine? I'm reluctant to take it for a test ride until I at least get some feedback from folks who might understand what I did and if I've royally screwed up, or if the brake bleeding fixes things.

In spite of this fiasco, I'm really happy that I was able to get the oil, final drive oil, and coolant changed. Couldn't have done it without the forum's help files.

'fooz

 

[FJRay]

It's a good idea to flush the whole system every couple years so I would bleed the whole thing. If it still has to much drag then pull all the pistons and clean them.

 

[wfooshee]

Caliper seals need replacing. They're not allowing the pistons to relax weill enough.

I kept putting it off and putting it off, and when the last set of front pads didn't even go 20,000 miles I decided I couldn't put it off any longer.

It's not inexpensive, you need four kits (2 of each part number,) and it'll be somewhere between 100 and 130 bucks. Then you have to get the pistons out, clean them, change the seals, reassemble and bleed. I say not inexpensive, even though that's not safe-deposit-box money, but it's an awful lot for 16 rubber rings.

 

[madmike2]

As part of my maintenance schedule I clean all the pistons. Lots road splooge collects on them and when you press them back in the bores to install the font wheel, they "stick" on the seals.

Walt is correct, it's best and safer to buy the seal kits and tidy everything. I may just be lucky because I've been able to clean mine in place...being VERY careful to NOT pop them out like you've experienced. Cleaning them is a pain in the tokus, it's very tight around the outside castings. Use a soft bristled brush, some strips of rag, brake cleaner and lots of patience!

 

[Zorlac]

Cleaning them is a pain in the tokus, it's very tight around the outside castings. Use a soft bristled brush, some strips of rag, brake cleaner and lots of patience!

I've rotated the pistons in the bores like this to clean them, it's still a pain in the arse but it works well for me.There is a certain amount of inherent pad drag on this bike but that makes for a quicker response time. When I looked at the price to replace the caliper seals I said, NFW.

 

[joebiodiesel]

The fact that the piston came out is not what caused the brake drag. If it didn't get cleaned or replaced properly may be the cause though. Finding the brake drag shouldn't bee too hard.

Raise the front wheel.

Pop one of the calipers off.

Spin the wheel.

If the drag is still present, remove the other caliper, and spin the wheel again.

Once you figure out which caliper is causing it, give it a good visual inspection.

Determine which piston is hanging up, then take it apart.

Any bumps, pits, corrosion, damage, whatever on the outside of the piston would warrant replacement. The pistons have a very tight fit in the caliper and don't tolerate any kind of distortion on the outside diameter.

Also, keep in mind that most brands of brake cleaner will cause the calipers seals to swell, and may be the cause the binding you are experiencing. The good news is that if you let the seal dry overnight it will often return to normal size. If you just put the piston back in there, and forced it at all, you may have damaged the seal and that's what is causing the binding.

You probably should have bled the other caliper too, but having air in there would not cause binding. A soft pedal, but not binding. Bleed it when you're done. I doubt you'll get any air out of it, but it only takes a couple of minutes, and it'll be good to get some fresh fluid in there.

Joe

 

[HotRodZilla]

Holy ****...I'm glad that didn't happen to me. I woulda freaked the f&%# out!

 

[harfooz]

Are there any videos of just how much drag is considered "normal"? I know that brake pad drag is considered "normal" but just how much is what I don't know. On my mountain bike, any drag is enough to have concern. But on the mountain bike, there are magnets and springs which pull the pads back away from the rotor.

So maybe I'm fretting over nothing. I can turn the wheel by hand, but only about 1/2 to 3/4 of a rev before it stops. The bike has 17K on it. The pads look good.

I wish I had spun the wheel prior to pulling out the front wheel to get the new tire put on it!

 

[Constant Mesh]

One way to check for excessive pad drag would be to feel the temp of the discs.

At your first cold start of the day take a short two or three mile loop around the neighborhood without using the front brakes. Stop and feel the temp of the front discs. If you don't detect any significant heating above ambient you'll know the pads aren't dragging all that much. But if you do detect significant heating you'll know the pads are dragging and wearing prematurely.

 

[03HiYoSilver]

Other than what was mentioned above,

did you get the Wheel Spacers put on the Correct side?

https://www.fjrtech.com/getdbitem.cfm?item=3

 

[harfooz]

Other than what was mentioned above,

did you get the Wheel Spacers put on the Correct side?

https://www.fjrtech.com/getdbitem.cfm?item=3

Yes. That was among the first things I double-checked.

 

[harfooz]

Found a video of a motorcycle wheel spinning that sounds and looks pretty dang close to what I'm seeing and hearing. (Except mine does not have that "chirp" sound to it.)



Do these look like normal or excessive drag? If it's normal, then I'm going to put the wrenches away and get out and ride this thing. The weather's cooler and I've been cooped up too long!

Also bled the other side of the front. Both front calipers have been bled now.

 

[wfooshee]

Mine spins just over two full revolutions. Before I changed the caliper seals I didn't even get what your videos show; it stopped immediately.

Order the seal kits and do it, or take it in and tell 'em what you want done. It's not an impossible DIY job (obviuosly, since I did it!) but on a scale of 1 being start the bike by yourself and 10 being engine/transmission rebuild, with the middle, a 5, being mounting your own tires, it's about a 6. The hard part is getting all the pistons out. Once the first one pops there's no more hydraulic pressure on the rest. You need them all out far enough to grab before you let one fall out, and they DON"T move evenly, as you've seen already.

I did it by removing the pads with the wheel still on the bike, putting a thin sheet of wood against the rotor and then pumping the brake. The wood keeps the pistons from moving too far, and since they stop you still have pressure to move the stubborn ones. Pull the wood pieces out, remove the calipers, and have at it. Don't let the brake fluid onto painted surfaces, of course.

 

[Harald]

Like wfooshee mentioned, wood shims work great for controlling how far out the pistons go. I have a couple pieces that are the thickness of the rotor plus the thickness of 2 brake pad backing plates. Theoretically, they designed the calipers so that the pistons won't pop out even if your pads are down to metal in all positions.

I use these wood shims to force the pistons out (but not so far that fluid is spurting) whenever I change pads so that I can thoroughly clean them before shoving them back into their bores. This ensures that I don't force crap into the seals which would lead to leaks or sticking pistons (and dragging brakes).

I've been doing this on cars, trucks and bikes for many years and haven't had to rebuild a caliper yet. Either this works great or I've been lucky.

 

[odot]

Holy ****...I'm glad that didn't happen to me. I woulda freaked the f&%# out!

Easy there, nancy. Don't get yer panties in a bind. Breathe deep and slow and count to 20. Have your wife(the ones with the pants on) check your heart rate and your blood pressure if you have the apparatus.

...and remember pups....be safe out there when you are reading topics in this forum.

 

[squeezer]

Caliper seals need replacing. They're not allowing the pistons to relax weill enough.

I kept putting it off and putting it off, and when the last set of front pads didn't even go 20,000 miles I decided I couldn't put it off any longer.

It's not inexpensive, you need four kits (2 of each part number,) and it'll be somewhere between 100 and 130 bucks. Then you have to get the pistons out, clean them, change the seals, reassemble and bleed. I say not inexpensive, even though that's not safe-deposit-box money, but it's an awful lot for 16 rubber rings.

This gets my vote as the winner. BTDT.