Brakes are stuck on after new brake pad install.

Hi all,

Thanks for taking the time to read. After fresh tires and fresh brake pads were put on by myself, I lowered the bike for the first time and pumped front and back breaks until I could feel the pressure.

Went to wheel the bike backwards to get out of the garage and it was a beast to move. I took it around the block to bed the brakes in and scrub the tires a bit. All felt really good. But on trying to free wheel the bike it was still a beast, almost unmovable. I checked the pads and all three sets were touching the discs. When taking off the old pads I made sure the pistons were pushed back in. And thought I'd done everything correctly.

Simple question, what's wrong? Do I need to bleed the brakes?

Thanks once again for your time.

Rossi

I don't ride a 1300 and not sure if all are ABS systems. However I have done several brake jobs.
1. If it's an ABS system and the key was turned on or either the front lever or rear pedal was engaged while the rotors( disks) were removed, , there could be proportioning valve damage.
2. If you failed to fully compress the caliper pistons when installing the new pads you could be experiencing excessive pad drag. I like to pull the discs then crack the bleeders and fully compress all the Pistons. This insures the Pistons walls are clean enough to move freely, it also allows your new brakes to adjust themselves properly. Remember to close the bleeders.

Hope this helps. My advice is worth exactly what you paid for it.

After you were finished, did you re-adjust the master cylinder(s) reservoir levels? If any brake fluid was added to the reservoirs before you changed the pads you may need to remove some fluid as they might now be overfilled as a result of pushing the fluid back up from the calipers. Alternatively, if you didn't clean the pistons before shoving them back past the seals, they could be hanging up.

Thank you both for quick replies. I'll try and answer in order.

Appologises forgot to say it's an ABS bike.
While changing tires and brake pads, key was out of the ignition. Neither brake was pressed during the service.
All pistons were fully back in the caliper, or so I believe.
Lowered bike and didn't turn it on, but pumped the front and back until they compressed. Then turned the bike on.
No fluid was added to either reservoir.
I didn't really clean the pistons before returning them into the caliper. I will certainly do that if I need to drop the wheels.

Thanks again for any advice.

Also, How would one go around cracking the bleeders, i'll look in the service manual. But any help is gratefully received.

Also I've just riding 7 miles with the brakes like that, obviously not good but is it going to be a fatal or costly 7 miles?

Thanks again for any advice.

It sounds like the SMC (secondary master cylinder) may be stuck. Many many threads on here regarding.

That would be the first thing I checked. The same exact thing, as you described, happened to me. SMC was the culprit.

Do you think its fixable?

Sure it is fixable.

See the pic in this post (not same issue as you, but shows the SMC).

https://www.st-owners.com/forums/attachment.php?attachmentid=174181&d=1464149689


This may be a simple test to confirm or rule out the SMC is the culprit.

Pull down slightly on that caliper thus extending the plunger back to its resting position (if it will move). You may also want to tap on it with the base of your hand. Doing so would cause my back brake to release although the next time I would apply the brakes it would lock up the rear brake.

For a professional in California, not sure how close you are to him (he's in San Jose), reach out to IGOFAR on this forum. He's the brake master here.


The SMC is located on the left side of the front wheel. The caliper "floats". When you depress the front brake, the caliper will pivot slightly on the pivot point (lower bolt) thus causing the plunger to be depressed into the SMC (the pic above - red circle, shows the yoke on the top of the plunger). The caliper will move toward the plunger when applying the brakes. See if it is stuck.

Thanks Joe, IGOFAR has helped me before, he's a legend. The picture you posted is the one I put up when he helped me.

In fact I had to turn that part as it was the wrong way on install. I wonder if I tightened it when I had to turn it? Is that even possible?

I've just cracked open a beer. Time for the Doctor to go to work.

Thanks all.

No worries, dang near everything in life is fixable. The bleeders are on each caliper, they should have a rubber boot over them to keep debris out. If they have never been opened they can be risistant to opening. Make sure you have a proper fitting wrench. I usually tap the free end of the wrench with a hammer to help break the bleeders loose.

At at this point I wouldn't mess with the bleeders. First I would level the front master cylinder then remove the lid. Slowly squeeze the brake lever and slowly release it. Look very carefully at the fluid in the master cylinder, you should a very very small amount of bubbles rising from the bottom of the resorvoir. The lack of bubbles indicates the hydraulic pressure is not being released allowing the Pistons to retract. MAKE SURE TO COVER ALL PAINTED SURFACES TO AVOID ACCIDENTAL CONTACT WITH BRAKE FLUID!

Let us know what results. There are a few causes for lack of the hydraulic pressure relief.

Rossi_46 said:

In fact I had to turn that part as it was the wrong way on install. I wonder if I tightened it when I had to turn it? Is that even possible?

Click to expand...

I believe it just rests in place so I don't think you could tighten it.

EDIT: Nope see pic. The plunger is just above the word "WHITE Pl....." in the pic.

https://www.st-owners.com/forums/attachment.php?attachmentid=154070&d=1403993297

https://www.st-owners.com/forums/showthread.php?139213-SMC-Rebuild

PM sent.....Waiting by the white courtesy phone.

Sometimes, it just happens:

ST1300-Rebuilding-the-SMC-Rear-MC-and-Rear-Caliper

Thank you once again for your help.

Tapped the caliper a few times which didn't release the back brake.

Removed lid from the reservoir and tried slowly pulled in and slowly released a few times and didn't see any bubbles whatsoever.

Removed the left caliper and could free the pads, but after applying the front brake the pad is compressed on again. However, could kind of separate the back pads a bit freeing the wheel a little and after pulling the front brake it hasn't moved. Does the bike need to be running? Depressed the rear brake pedal to see what happened, brake is now compressed on the disc.

If you were in SoCal I'd be supplying you both a cold beer.

Rossi

Rossi, PM me your phone number and I will call you.

Thanks pal. I'm trying to log into Hotmail to get yours but the site is down. I'll send it now, you're a legend!

Thanks

Rossi,

For my two cents....
I just picked up a 1998, got it home and gave it a good once over. Brakes were dragging something awful. Thought about just pushing out the pistons a bit and cleaning them up, but took them out instead. WOW, the sludge and waxy build up behind the pistons was amazingly awful. NEVER thought it would be that bad. New seals are only $5 per piston, so it didn't cast much to fix it right. It was a real mess to do it, but pretty easy. Now I feel a ton better about the brakes. Rotors are a bit worn, but lots of life yet. Pads were about half gone, so I replaced them right away...

Question, why did you change the pads? Noise, lack of braking, pulsing or something else. Point being, if you had functioning brakes and simply change the pads because it was time, then the odds of any cylinder giving up the hunt is pretty low. However by depressing the Pistons fully back into calipers without opening the bleeders a bit creates a possible back pressure problem. It can cause the tiniest amount of debris to migrate to the proportioning valve or clog the small pressure relief hole in the bottom of the master cylinder. Without the tiny bubbles it seems the system is not being allowed to relieve the pressure created when the lever is applied. Without pressure release the Pistons stay extended supplying continuous force to the rotors.

Again I don't ride a 1300 but I do ride a 1100, a Wing, a VFR and a Vulcan, all have hydraulic brakes and clutches. I just put all new brake lines on my VFR last week, I had hell. What should have been a few minutes to put new dot 4 fluid and bleed turned into a 2 hour puzzle. You have all brakes and I couldn't get any. My issue was that stinking little wheel between the brake lever and master cylinder, sorta like a vertical quarter, was out of adjustment for the new lines. It adjusts the amount the piston moves in the master cylinder. To little stroke and the system won't build pressure, to much stroke and the piston in the master cylinder does not retract enough to allow pressure relief. Fast and easy to check. Good luck.

Thank you STing and Hibobb and again to all involved. I can't thank you enough for such quick and great advice. Sorry it's been an hour or two until I replied. I've had a fantastic chat with the legend that is IGOFAR. What a nice guy, as you all are with helping out a fellow ST rider. You guys go far beyond the call of duty, thanks from the bottom of my heart.

An update, STing - The reason for changing the pads was that it was about time, no faults, just knew they needed changing. I was changing the tires and thought to do them at the same time. As this is the first time of doing said items, I removed the front pads and found that there were white spacers and also a metal cage holding them on to the old pads. I removed them and kept them to one side thinking I would put them on the new pads. I assumed, tut tut..... that this was the correct thing to do.

It transpires that they should not be on the pads and that they would have added an un-needed width to the pads. So hopefully it means that with the extra width I've added the pistons haven't reached their point of return, meaning that they still think they need to be on. I'm about to remove the white spacers and re-attach the calipers. Hopefully the pistons will now realize that things are normal and I'll have full brakes back again.

The only thing to have changed is the pads, I'm hoping that Sods law doesn't kick in and that my SMC is good and it was just user / ID10T error.

Enjoy your evenings, and update will follow.

Rossi

The rear pads are slightly thicker than the front ones but they will fit into the front calipers. You should use those shims/insulators behind the pads. Is there any chance you fitted rear pads to the front?