Pad Drag and Temperature....

Thank you again for all the advice! I know this may seem basic, but I'm still getting to know my way around the ST and it is a whole lot more complicated than the circa 1980s Guzzis.

Finally finish rebuilding all three calipers and replacing seals and Honda pads on the ST1300 2004 non ABS. Everything looked good inside....no corrosion or pitting on the pistons and old seals looked to be in good shape, but figured I'd go ahead and replace anyway.....that way there is only me to blame. Followed the bleed to the letter! Greased the pins and tourked to spec.

Question:
1. Is a certain amount of pad drag normal?.....rear wheel spins without much pressure, but you can hear the drag. Same with front.
2. Rotors are warm to the touch without brake use after a few miles. NOT blistering......can be held without taking the Lords name in vain.....hot when used, but seem to release fine and cool down. Taken uip to higway speeds.....and pulled off...geared down to stop.....and rotors were well with the hand holding temps.

Am I being overly sensitive? The system seems like it is working just fine......All the stopping power......pulled a handful and rear didn't pass me up, and stood on the rear and felt solid....so pressure and release and SMC seem to be doing their jobs.......ALTHOUGH there seems to be a relation between the Left front and rear from the heat standpoint.

Thank you in advance for any insights and advice.
IF

All disc brakes have a little drag. Just as an FYI, cars normally with drum brakes have a residual valve with 10 lbs to keep the shoes closer to the drums; disc brake cars it is only 2 lbs. If there is a valve built into the ST brake system I'm not sure where it is. That being said, disc's are not alway true and will have some run-out. This run-out will push the pads back and the slight rubbing will generate heat.

It sounds like your brakes are working perfectly normal.

A slight amount of drag is normal. Keeps water and road trash from building up on the disc and from under the pads. A little drag is inevitable. The wheel should spin freely and the disc will remain warm when riding. Too hot to
touch?....bleed it and troubleshoot the system.

The left front caliper operates the SMC. It's important to keep the mounting points of the left front caliper cleaned and lubed with a waterproof grease to allow the caliper to pivot freely. If you did not address the needle bearings in the lower pivot point, you should the first chance you get.

One other thing I noticed was a fair temperature difference (5-10 degrees Celcius) in the front and rear rotors, rear being hotter. While I know my rear drags a little (you can hear it singing as it spins on the center stand) I does not seem to be much drag as I managed well over 50 mpg on a recent tank. I believe the temperature difference, front to rear, has more to do with those large exhaust pipes travelling right next to the rear rotor.

I had a laser temperature reader on my rotors several times over this weekend at OnSTOC and always noted a higher temperature at rear, even when I used only front brakes (yes I know linked).

Just my $ .02 (Canadian, so $ .016 US with exchange).

"I had a laser temperature reader on my rotors several times over this weekend at OnSTOC and always noted a higher temperature at rear, even when I used only front brakes (yes I know linked)."

I used one also last year when I replaced my pads. I found that after running on the highway for about 15 minutes, if i coasted to a stop, the rotors would be about 30c-35c. Warm - but not hot enough to burn. I've always been uncomfortable with the 'hot, but not too hot' feedback I got on the board, and needed something a bit more 'real' to measure against.

Hope that helps.

Mikedo said:

One other thing I noticed was a fair temperature difference (5-10 degrees Celcius) in the front and rear rotors, rear being hotter.

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The rear isn't out in the open air like the fronts, and 5 degrees is noise. When you get a rotor with a drag problem, it'll stick out like a hot sore thumb.

--Mark

Blrfl said:

The rear isn't out in the open air like the fronts, and 5 degrees is noise. When you get a rotor with a drag problem, it'll stick out like a hot sore thumb.

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Mark is right here I have a rear brake dragging in after a short ride on my 03 I could touch the rear pad no issue on the 04 with the dragging brake it will burn you if you touch it don't ask me how I know. I am continuing to work on the 04 it has a new SMC and a new rear MC but is still dragging.

Thank you all for the advice and observations. I will pull the Lf front and address the pivot points on my next day off. Great to be back on ST, but now the wife wants the garage back for the fall "honey doooo list". Even on the ST, that is something I can't out run. Will continue to monitor, but feeling much more confident about the end result. Next project is to install fog/running lights. Any suggestions on a modestly priced set??

motoguzzian said:

Thank you again for all the advice! I know this may seem basic, but I'm still getting to know my way around the ST and it is a whole lot more complicated than the circa 1980s Guzzis.

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Boy, you sure got that one right! But on the other hand, ST's handle so much better, accelerate so much faster and more smoothly, are so much quieter that there is really no comparison. I liken my ST to a 2013 Lexus and either of my old Guzzi's to a '67 VW bug.

I rebuilt my T3 and SP 1000 w/o major trauma, but I find the ST intimidating - not insurmountable, but the complexity begs help and consultation. Fortunately there is loads of that here.