Front Wheel Not Spinning Freely

[BSTWAY]

Over the past five years I’ve noticed that my back wheel has never spun freely but the front always has during tire checks, washing etc. I just replaced the break fluid and now the front doesn’t spin freely. I don’t recall whether this is normal right after (before taking a spin) replacing the fluid or not. But I’ve noticed it this time and not sure if maybe the pistons aren’t retracting properly or something of that nature. When I change the brake fluid I remove the calipers and retract the pistons. This hasn’t been a problem in the past but maybe this time something got behind the seals. As you can tell, I’m not sure. Would taking it for a ride situate things? I’m just a little paranoid because of the potential heat generation if this isn’t normal. Any help/advise would be appreciated. Thanks.

[boxermania]

Well, to many unknowns to attempt a diagnosis, howvever, as the owner/rider I have to believ what you say about the free wheeling.

Additional info would be important, such as:

Mileage on the bike?
When was the last time you cahnged the fluid?
Was the fluid change done by you or the dealer?
Are you a front brake user, or basically do you use the front brake at all?
With the bike on the center stand and with a good pull, does the wheel turn at least a couple of times?

The above should give enough information for a diagnosis..................

[MikeCam]

First thing that occurs to me is too much brake fluid during the refill.

[BSTWAY]

Thanks for the reply Boxermania. The bike has 42K miles and I ride year round and in the rain. The Brake fluid was changed a year ago and every year prior by the dealer. However, I did change it myself two years ago. My first thought was I had retracted the pistons when I did it myself. But upon further reflection I don't believe I did. I'm definately a front brake user. With a good pull, the wheel will almost go only one turn.

I'm starting to think some crud has infected at least the dust seals so they are not able to help in retracting the pistons (but thinking has gotten me into trouble before!). It would be nice if I could resolve this issue by merely retracing my steps and give everything a thorough cleaning.

Your words of wisdom would be greatly appreciated.

[OU812]

Did you by chance replace the pads recently? Or have the front tire off? If so Mike Cam has the remedy for this.

[BSTWAY]

The pads are origianl and have never been removed. New tires were mounted a year ago. I believe my issue is directly related to not cleaning the exposed pistons and caliper serfaces prior to retracting the pistons. My bad; just trying to see if it can be remmedied without taking the calipers apart.

[jm1515]

Over the past five years I’ve noticed that my back wheel has never spun freely but the front always has during tire checks, washing etc. I just replaced the break fluid and now the front doesn’t spin freely. I don’t recall whether this is normal right after (before taking a spin) replacing the fluid or not. But I’ve noticed it this time and not sure if maybe the pistons aren’t retracting properly or something of that nature. When I change the brake fluid I remove the calipers and retract the pistons. This hasn’t been a problem in the past but maybe this time something got behind the seals. As you can tell, I’m not sure. Would taking it for a ride situate things? I’m just a little paranoid because of the potential heat generation if this isn’t normal. Any help/advise would be appreciated. Thanks.

This always happens to me (to some degree) whenever I remove the calipers for cleaning, wheel change etc, and I'm hyper-careful about getting crud past the seals.
Prior to caliper removal= many revolutions with just a 'kiss' of pads on the rotors.
After replacement= 3 or 4 revs at most and obvious (but not excessive) pad 'drag'. Some pad contact is normal.
As long as you didn't remove the wheel so as to potentially screw up the fork alignment, I would not worry too much.
YMMV, but my front always gets back to 'free spinning' after some miles and normal braking. But this is what I would do whenever I service the calipers...

Pull a caliper and insert some decent weight, clean, folded cardboard in between the pads. Your cardboard spacer should be at least the thickness of the rotor, thicker = better.
While watching the pads/cylinders, squeeze the brake lever slightly to push the cylinders out.
Clean those cylinders like a MoFo...I use a miniature bottle washer brush, compressed air & conservative amounts of BrakeKleen.
Press those cylinders back in as far as possible (I pull the brake lever all the way out at this point, don't know if that makes any dif ), and re-install. Do the other side....

At this point, my wheel normally does not spin as freely as before, but after some miles and some normal braking, it invariably does. Depending on how much pad drag there is & just to make myself feel better I'll take a spin on a long straight at a decent mph, brake as quickly as I can using the rear only, hop off and touch the front rotor.
After a service it's always luke warm- to warm, but should never be to hot to touch.
I spot check & clean my R after every ride, so I know my wheel always, eventually, gets back to that free spinning with just a kiss of pads on the rotors....

[def38]

Here is how I bleed my brakes. Mind you, I ride a '01 GS so I caution you here...make sure your model's brake system is similar.

Take an empty gallon milk jug and make a hole in the neck of the jug the size of clear plastic tubing that fits the brake bleed nut. I use the tubing from my Carb Stix. It is the correct size. Insert your shop vac nozzle into the milk jug and insert the tubing into the hole you made routing the tubing down near the bottom of the jug. Open the front brake reservoir and turn on the shop vac. Yes, the milk jug will collapse...not to worry.

Now, vacuum all the old fluid out of the reservoir making sure you remove any solids or debris at the bottom of the reservoir. Use a small Q-tip or similar object to scrub the bottom of the reservoir. If you must, use brake cleaner carefully and don't allow the brake cleaner to remain in the reservoir for long. And, do not actuate the brake lever with the brake cleaner in the reservoir. Refill the reservir with fresh DOT4. Now, attach the vacuum tube to the bleeder nut on the caliper. Open the bleeder nut well open to get good flow of old fluid out of the lines and caliper making sure you do not emplty the reservoir (you may need to top off the reservoir during the process). Bleed until you see no air or old fluid. Snug the bleeder nut and top off the reservoir to the mark, no higher. Actuate the front brake carefully (watch out for DOT4 it damages paint quickly) and feel for proper brake operation. If the brakes work properly, button up the system. If you still have brake release issues, more evaluation is needed.

[towerworker]

No one has mentioned this yet but a simple test would be to pull one caliper at a time and give the wheel a spin. That would tell you which side (if only one) is dragging. If you pull both sides and it still turns slowly then you have a bearing issue.

Wayne

[OU812]

Another try might be to align the wheel. My memory is not the best but I will give it a try. Loosen the axle and the front retaining nuts that hold the axle on the forks. Roll the bike back and forth and bounce the front end a few times. This worked for my R when I had the tires replaced and the front wheel was dragging.

[boxermania]

BSTWAY

Yep, based on your response there is some dirt that has found it's way past the seal and is holding up the piston ever so slightly not allowing the piston to spring back.

I recomend proceeding as suggested by towerworker to find which caliper is the culprit and carefully remove the dust seal to see what you find, if there is crud around the piston I would go ahead and rebuild the calipers and start fresh and secure, after all, is only the brakes.....just kidding of course.

[BSTWAY]

BSTWAY

Yep, based on your response there is some dirt that has found it's way past the seal and is holding up the piston ever so slightly not allowing the piston to spring back.

I recomend proceeding as suggested by towerworker to find which caliper is the culprit and carefully remove the dust seal to see what you find, if there is crud around the piston I would go ahead and rebuild the calipers and start fresh and secure, after all, is only the brakes.....just kidding of course.

boxermainia

If I remove the dust seal I should have a replacement on hand correct? If rebuilding is necessary, can you get the pistons out without splitting the caliper? Are there any known documentaries on this site or others that run through the rebuilding procedure? From the manuals (BMW, Clymer) discussions, it looks straight forward, but the more info the better. I would assume there is a rebuild kit available containing the necessary seals?

[Arbee]

It seems the most important question hasn't been asked yet !

So i will be brave enough to ask it .... Does the bike have ABS fitted ?

Diagnosis : Go a for a 5 minute ride without touching the front brakes
then take your glove off and feel the temperature of the disks, that will be a clue.

Cheers
Arbee

[Boxer]

Arbee gets my vote for the smartest one of you guys today.

[BSTWAY]

The bike does not have ABS. I've taken a couple of test spins for a total of 28 miles. I did the aforementioned touch test and neither rotor was hot. In fact, after excessive slowing and stopping neither was too hot to touch. After the last ride, I was able to spin the wheel several revolutions with a good pull. Others have said this type of thing can work it self out after a few rides. Maybe that’s what’s happening here. What do you guys think? I really appreciate all of the insight and knowledge provided in your feedback. Thanks!

[CycleRob]

When you push in dirty caliper pistons, most of the dirt is scraped off -but- some of it slides under and past the seals. Since there are millions of M/C's riding around with pushed-back-dirty caliper pistons, it's not a condition that needs an immediate disassemble and clean. You should put it near the top of your short list if you like things perfect and want to avoid possibly causing uneven or slightly accelerated pad wear.

The dirt isn't what's causing the drag after caliper removal. It's caused by uneven extension of opposing pistons against a floating rotor. That's normal because of minute differences in seal drag (of opposing pistons) combined with very light rotor deflection resistance. This "wheel drag thing" happens to me almost every time I remove the wheel. Even when the pads are removed, then calipers removed before the pistons are extended and cleaned, the wheel still binds some after careful reassembly. The solution is to go for a short ride where you can quickly do several consecutive hard-but-short front brake applications. Even do it with the gas "on" so it happens quicker. That hard short brake application forces the rotor to center itself on the wheel mounts and the pads follow. After that, they should be centered and the wheel spins free. If it doesn't spin easy, you likely have gunky, dirty, sticky caliper pistons.

Taking apart the calipers is easy and not to be feared. The hardest part, since most people won't have an expander tool like the one in the pic below, is to pump all the pistons EQUALLY to maximum extension without coming out of the bore. Remove the pads, then the caliper from the forkleg and put the largest size wrench handle that will fit in the rotor space. Those 2 wrenches will prevent the pistons from falling out as you pump the lever, while having them so far out of the bore that you'll be able to turn and remove them with your fingers AFTER the caliper halves are split apart like this:

http://i142.photobucket.com/albums/r87/ ... aliper.jpg

When everything apart like above, you can gently push a small blade screwdriver alongside the seal and pry them out for manual cleaning of all 4 flat surfaces of each seal ring with a paper towel. Be careful so you do not scratch the machined Aluminum seal ring groove surfaces. DO NOT USE BRAKE CLEAN ON RUBBER PARTS !! If you need a liquid cleaner, use your paper towel dipped in new brake fluid. Thoroughly cleaning all 16 seals of the 2 front brake calipers can take at least a half hour. Submerge them in brake fluid before reinstalling them. Also dunk the piston head halfway submerging the piston in DOT-4 for easy hand insertion into the caliper. Then wipe up any dribbles. You can moderately spray your paper towel with brake clean for the cleanup of the area and painted surfaces. Work quickly, it evaporates fast.

BTW, The expander pliers in the pic above were purchased from the Duluth, GA Harborfreight tools store. I just did a thorough search and the H-F WebStore does not list them. It's a plastic pouch of 2 pair 12" long snap ring pliers, one straight, one curved 90deg. I cut off the excess length with an airtool powered cutoff wheel and ground "feet" into the remaining stubs. Made of hardened steel a hacksaw cannot cut, they work perfectly and are really powerful . . . . . also for many "other" wrenching spread-apart uses. If you're a May or Oct future Bash attendee and would like to purchase a C-R modified tool like in the pic, PM or E-Mail me.

.

[BSTWAY]

CycleRob,

Thanks for the valuable info. I definitely will need to be more diligent with cleaning in the future. Besides the hydroscopic issues, I thought keeping the brake fluid fresh helped keep everything from being gunked up.

Do you happen to know the torque values of the bolts used to keep the two caliper halves together and I assume you would lock tight these? It’s interesting that the BMW manual (p. 249) warns not to separated them. Since there aren’t any seals to worry about, I don’t see what their problem would be. Plus, I don’t see how you would easily remove the pistons through the caliper opening. It seems at least two opposing ones would be out simultaneously thus conflicting with there separation from the bore