Rear Brake problem

All,

The parts came in yesterday and I worked on this most of today.

End results the rear wheel is still locked up

I did the following

1. Replaced rear pads
2. installed new caliper spring
3. Bleed the brakes as per the web site
4. Clean all brake areas



Rear wheel is still loced up ?

Ideas?

The best idea I have is call Igofar ASAP.
Can't wait to see what he finds wrong with this situation.
I putting money on you have a failed SMC.

If you have replaced the SMC maybe you have the spring clip in wrong which is causing the pads to stick. Good luck finding the problem.

Standing by...:call:

I don't mean to jump in and hijack the thread but on the topic of rear brakes I was out for a good ride today (first of the season) and noticed that when I come to a stop, the brake pedal sinks just slightly as the SMC retracts on the front. I did do a flush with air powered mitivac last fall. Is this normal or do I need to go in and manually bleed that SMC and PCV?

gsforster said:

I was out for a good ride today (first of the season) and noticed that when I come to a stop, the brake pedal sinks just slightly as the SMC retracts on the front.

Click to expand...

I've have the same thing before... don't worry much about it. BUT, a full and proper flush should remove 95% of it.

** don't forget to tilt the smc unit during the bleed...

Tom Mac 04a said:

don't worry much about it. BUT, a full and proper flush should remove 95% of it.

** don't forget to tilt the smc unit during the bleed...

Click to expand...

Thanks! I will maybe do a rebleed on the system then. I see mention numerous times here of Igofar's motion pro brake bleeding tool - was wondering which exact model that one is?

All,

Thank you for your support, I am off for Easter service however I wanted to drop a note. I was thinking last night that I may need to rebleed the bike again, everythin was working until I cover the master and handlebar brake cylinders., and put presure on them. The rear brake calipers anad smc moved freely...I am thinking I missed some air?

Happy Easter

Tim

:call: later tonight....happy easter.

gsforster said:

Thanks! I will maybe do a rebleed on the system then. I see mention numerous times here of Igofar's motion pro brake bleeding tool - was wondering which exact model that one is?

Click to expand...

This is the Motion Pro Brake Bleeder that Igofar disciples use. It sure simplified things for me. I used to get my wife to help me bleed the brakes. She worked the lever or peddle and I worked the bleed screws. Now it's a one man job so don't have to bug her with this chore.

Tim D. said:

All,

Thank you for your support, I am off for Easter service however I wanted to drop a note. I was thinking last night that I may need to rebleed the bike again, everythin was working until I cover the master and handlebar brake cylinders., and put presure on them. The rear brake calipers anad smc moved freely...I am thinking I missed some air?

Happy Easter

Tim

Click to expand...

It's been a week. Hope you have found the source of the problem and are back riding. Any update or still locked up?

All,

Well the adventure keeps on giving, today I did the following items to the bike and found a front brake pad with a strange pattern on it.

1. Bleed brake system again following instruction on the ST 1300 owners sites, no success the rear and left front were lock up. Maybe air?
2. Removed both sets of front brake pads found a pattern on the right front outside pad, see photo
3. With front brakes removed and the calipers hanging the back wheel was still locked all three piston were extended


My thoughts are the SMC is locked up, however how would that explain that all three pistons were extend in the rear caliper?

PULLED ON SHOTGUN and though about solving the problem that way. Placed a call to IGOFAR instead.

Any ideas ?

Tim

That pad looks like it is hanging up on the pad retaining pin OR on the spring above the pads OR both..... OR the piston nearest the retaining pin is sticking in its barrel and not pushing out properly..

Not sure if this could be caused by air in the system as well, in the piston barrel at the pin end again....

Is the pad on the other side of the disc wearing slightly uneven also, although much less so?

Thank You for the feedback

The pad on the other side looks fine these are SBC pads and not Honda, IGOFAR suggests a switch over to the Honda pads

I did find that the right side was not moving as freely as it should so I cleaned and lube the slides.

What does not make sense is that the rear brakes are locked up and they are no pads in the front...SMC? or air?

I DO not know

Tim

Tim D. said:

All,

Well the adventure keeps on giving, today I did the following items to the bike and found a front brake pad with a strange pattern on it.

1. Bleed brake system again following instruction on the ST 1300 owners sites, no success the rear and left front were lock up. Maybe air?
2. Removed both sets of front brake pads found a pattern on the right front outside pad, see photo
3. With front brakes removed and the calipers hanging the back wheel was still locked all three piston were extended


My thoughts are the SMC is locked up, however how would that explain that all three pistons were extend in the rear caliper?

PULLED ON SHOTGUN and though about solving the problem that way. Placed a call to IGOFAR instead.

Any ideas ?

Tim

Click to expand...

I feel your frustration. Over many years I have found that problems that suddenly arise after service work was done is usually directly related to something that was done during the service. I don't mean to be contrite when I say that. The could be cause by procedural mistakes or ill fitting parts. I would go back to basics. on the rear brake can you pry the pad back while it is installed and see that the wheel spins freely? I didn't catch earlier if you said whether this is an ABS or not. I doubt that air in the system would cause the brakes to drag or lock up. Air would cause spongy brake feel at the lever of pedal and increase the lever travel. I doubt also that all three pistons are applying at the same time as they are on separate hydraulic circuits. The floating calipers used here are retracted only by run-out of the rotor disc and elasticity of the square profile O-ring seal on the piston. If they do not retract and are dragging the cause could be either something binding (pads or slides are most common) or a something in the hydraulic circuit that does not let the pressure bleed off (return to the master cylinder) after the brake is released. Incorrect Master cylinder push-rod adjustment or sticking Secondary master cylinder could cause this as well but the likely cause is fitting of the rear pads. As an experience Tech I found that the rear pads are very touchy on the 1300. Twice I have had issues getting the rear pads installed correctly. Both times the pads seemed to go in and the pin installed with no problem but the front of the pad was not seated in it slide. The result was after a 1 mile ride the rear brake was dragging and smoking hot. It sounds like you have done everything recommended here. What could you be over looking? Look for the simple explanation first. Hopefully Igofar can guide you. He seems to be the go-to technical guy when we get stuck.

Thank you for this advice as it makes sense, this is an ABS system and the rear brake was looked up after and oil change, the bike was not used last year due to a surgery on me. SO when I started the cleanup and dust off II found the rear wheel locked up. This was before I replaced the pads. However after the pad replacement and bleeding it is still not working correctly and I am thinking the SMC. What is confusing is that all pistons in the rear are extended, with the front brakes removed?

Normally all 3 rear caliper pistons are in contact with the pad. Otherwise there would be loads of pedal travel to engage the brake. They only retract probably less than .5 millimeter (my guess). If you pry the pad away from the caliper with the pad installed does the rear wheel spin freely? I'm not clear on what you are saying about all three pistons are extended.

Tim, sorry I didn't get a chance to call you back yesterday, was trying to hold a slippery fork tube, and dealing with a nice slash on my right index finger, and couldn't tell the difference between the fork oil and blood didn't get done until well after dark and didn't want to call that late, I will call you later this afternoon when I get to work.
Larry

The wheel spins freely with the exception of the rear brake dragging it will spin 1/4 to 1/2 rotation and then stops. All bearings are in good shape. I know that I should be able to compress the rear caliper and have the pistons pushed back into the caliper. There seems to be "locked" pressure ion the brake line. keeping the brakes from working correctly

Larry,

No issue and it sounds like you had your hands full I have a number of items on the to-do list today so I hope we can connect. I have review RonAryers .com and it is a good source as you said it save $$$$ Thank You for the tip!

Tim