Rear wheel binding

jettawreck said:
To make the Kleensert or Heli-Coil work on that caliper it would need to be very accurately bored out in perfect alignment
Click to expand...
.
The helicoil or Kleensert would be an inexpensive fix. I believe a small drill press would provide ample accuracy. It can be verified by installing the caliper without the pads and assuring the caliper will slide easily by hand. In the odd case that it doesn't work you are out a only little time and a helicoil and would no doubt learn the limits of your machining skills.
 
Got the new-to-me caliper and it looks good. I noticed right away the difference from my old one: The front slide bolt can be threaded by hand easily. As you may recall, that was not the case with my old one. I'm hopeful. A couple more questions: I've search the forums and the Honda shop manual and haven't found a really clear description and/or photos of how the piston seals should be installed. Any help on this one? Also, what kind of grease should I place on the slider bolts and pin which holds the rear of the brake pads in place? Thank you!!!
 
Dr. Kauz said:
... A couple more questions: I've search the forums and the Honda shop manual and haven't found a really clear description and/or photos of how the piston seals should be installed. Any help on this one? Also, what kind of grease should I place on the slider bolts and pin which holds the rear of the brake pads in place? Thank you!!!
Click to expand...

With the pistons removed (and unit nice and clean), put a LITTLE brake fluid where the seals sit in the caliper, put the seals in (the correct way) and put a LITTLE brake fluid on the seals, then insert the pistons (the proper direction). Make sure there is no brake fluid on the outside of the caliper where it could get on the pads!

Get some brake grease for the pin. Just a small tube.

I would mount the caliper with pads in over the rotor and then attach the hoses (this way you aren't fighting everything.) then start the bleeding! (of the calipers, not your wrists! :eek: )

Good luck!
 
jfheath said:
Make sure that the grooves are clean. Use a sharp wooden cocktail stick or plastic toothpicks or similar to scrape around in the corners of the square section groves. Don't use anything that would scratch the metal itself.

Put the oil seal in first (the one that sits deepest in the hole. Smear it with brake fluid first -it will seem to be too big, but make an oval out of it and sit the pointy end into the groove and put your finger over it to keep it in place. Then slide the rest of the distorted circle down the cylinder - and it just pops into position. There are stories around which suggest that the seals have a trapezoidal shape (a shamfered face) and that it matters which way up they go - but I have never seen that - and I have looked closely under an illuminated magnifying glass. They are cut square.

Do the same with the dust seal, but smear this with silicon or rubber hydraulic grease. Its easier to do all the oil seals first and then all of the dust seals. Saves getting fluid and silicon grease mixed up. The information about the two different lubricants is taken from the shop manual.

Smear the closed end of the piston with brake fluid and slide it in so that it pushes past both seals. Don't push them all the way home yet - just in case you need to take them out again.

I'm trying to find the torque setting for the slider pin for you. I'll be back.

[Edit] Told you I'd be back. I knew I remembered an issue relating to this bolt.

The diagram in my UK A2-A4 Workshop manual says to tighten the slider pin into the caliper to 69Nm / 51lbf-ft.
This is on the diagram on my page 17-40 and I BELIEVE THAT THIS IS WRONG !!!

The diagram seems to be confusing the slider pin with the caliper stopper bolt which fastens through the frame and pokes through the hole in the caliper bracket to prevent it from rotating around the axle when the brakes are applied. This is a heavy duty bolt and its torque is indeed 69Nm.

The table in general information - Hydraulic Brake - Rear Caliper Main Slide Pin 12mm quotes the bolt as requiring a 27Nm, 20 lbf-ft torque.
The other slide pin (8mm thread) requires 23Nm , 17lbf-ft torque.
The same table shows the 18mm thread stopper bolt as requiring a 69NM torque.

The above information is on Page 1-18 in my manual - and contradicts the information in the diagram on page my page 17-40.

There is a Note 2 hovering between these two slider pin entries in the table. Note 2 says 'Apply a locking agent to the threads'. This is on my page 1-12 - immediately under the heading Engine and Frame Torque Values.

It occurs to me that your threads might have been damaged in the first place by someone following the torque setting in the diagram. 69Nm shown on the diagram is exactly 3 times the torque specified in the table.

Please check it out for yourself though - rather than taking the word of a stranger on the internet. I'm just alerting you to a contradiction in my A2-A4 manual !!

------------------------------------------

Grease. Use Silicon grease on the piston outers and in the boots into which the slider pins fit. Not too much in there - you can get an airlock which pushes the pads against the disc rotor. I put some on a Philips driver blade and wiggle it around inside to distribute it, and to ensure there isn't a large blob. I've encountered the binding brakes that arise from these first hand.

For the pad backs use a smear of Moly paste M77, or brake back (Cera Tec) grease, or copper grease is better than nothing. I used Copper for years, but it is now out of favour due to the possibility of an electrochemical reaction between the copper and other metal - resulting in corrosion.

[/Edit]
Click to expand...
Thanks for taking the time to provide all these specifics! I'm almost ready to rock on this thing once I get the time and my new seals come in.
 
jfheath said:
This is the rear caliper, but it is easier to see 'cos the two halves are split. The front caliper has the seals in much the same position. The oil seal is arrowed - this is the broader one. The dust seal is the obvious black band above the oil seal, closer to the top of the cylinder.

To get them out, a dentist probe is useful if you have one, but a needle or pin will do the job. Don't try to prise it out - spear it at an angle and lift it out like that - much less chance of any damage to the metal. OR Use a wooden toothpick to try to get behind it.

The red stuff is silicone grease (rubber grease for hydraulics). I use this on the dust seal and on the outside and inside of the pistons after they have been inserted. The oil seal (arrowed) gets coated in brake fluid, as do the pistons before insertion.

View attachment 233715
Click to expand...
Got it. Was just needing more light to see it all. Thanks again!
 
Finally got the time to rebuild the caliper (I reused old pistons in new to me caliper) and bled brakes and things seem good. Can't try it out since we got 13 inches of snow here in Greensboro, NC the other day. So, while the plastic is off I might as well perform a coolant change, change oil, and poke around with other things until I can trust the roads.
 
Rear caliper rebuilt, brakes bled, engine oil and filter replaced, final drive oil changed, coolant flushed and changed. Gonna try it out Saturday.
 

Attachments

  • 20181218_164942.jpg
    20181218_164942.jpg
    112.7 KB · Views: 11
  • 20181220_173111.jpg
    20181220_173111.jpg
    121 KB · Views: 11
IT'S OVER AND IT'S PERFECT! Rear wheel spins beautifully after applying brakes. Tested many times on a 14 mile urban drive this morning. It was definitely the crossthreaded front slide pin on the rear caliper that caused the problem. I can't thank you all enough for the support and cheerleading. Hopefully this thread can be useful to others!

Details: a used caliper body from a nice st-owners participant mailed from Washington state. $60, which was very fair. Pistons from old caliper were in better shape so those were used. Cleaned up nice just with brake fluid. All new seals installed in pistons. Bled the brakes three times. First time was just a learning experience. Third time I nailed it with my son's help on lever and pedal.
Then, engine oil and filter replaced, final drive oil changed, coolant flushed and changed. Next up: air filter check, clutch fluid change, valve check, and so on.
 
Congratulations and job well done sorting this out. You can now ride with confidence that your STeed’s brakes will work as designed.
 
You must log in or register to reply here.
Back
Top Bottom