Caliper reassembly - What gets lubed?

I'm about to put the caliper back on my 650. I've done this once before (on a 550) but I can't remember what gets lubed. It's interesting some of the things that aren't in the factory manual. I did not remove the piston and rebuild (probably later), so I'm just putting on new pads and remounting it. Specifically...

1) mounting bolt sleeve: inside and out?

2) pad slide pin?

3) the plate spring behind the pads?

I've got some of that fancy high-temp ceramic brake assembly grease plus other stuff. Thanks.

 

I would only lube the pad slide pin myself. unless your caliper moves on the mounting bolts I see no need to lube them.

 

1) Yes!

2) Yes!

3) No!


Make sure the pads move freely on their pin....sometimes you have to file the holes a bit to remove the powdercoat........

 

Thanks!

 

#2: SPARINGLY!!! (I just put a small dab in the holes in the pads themselves, and then be sure to wipe away any excess that could even conceivably find its way onto the pads.)

Otherwise, I concur with Len, including cleaning up the powdercoating.

 

Thanks, Fitz. What about the tabs at the top of the pads that fit into that retainer?

 

I decided that there might be a chance of some grease falling down from those tabs onto the pads so I opted not to lube them.

However, now that I put the caliper back on the bike, I think there's something goofy with how the pads are sitting. The pad on the inside (away from the cylinder) is moving very freely. No tension on it at all, if fact - just wobbling there. The outside pad, though, is pretty wedged in place. I think it must be from the spring.

You may recall that I had some questions in an earlier thread about how my plate spring and pad retainer were a little bit bent. Now I'm wondering which pad is installed correctly and what I need to do to adjust the other one.

For what it's worth, the wheel is off the bike.

 

One brake pad tight, one loose

Sorry to bump my own thread, but I need some input on this as described in my last post yesterday. Thanks.

 

Don't worry about the pad "wobbling about" if the disc isn't in between them yet. Once everything's assembled and the caliper bled, they should all "line up." (Such that they do on that brake; The caliper starts off at a rather odd angle because of the wedge-shaped pads, and as the pads wear, it "straightens out.")

 

Thanks for your reply, Fitz! So I shouldn't worry about the pad that's more tightly wedged? I'm just not sure how freely it should "slide" on the slide pin. I realize that they don't move very far.

 

As long as it can still move and isn't completely bound up, it should be fine. Braking forces will square it up.

 

Yes, I can move it but it takes some doing. Obviously I can take it off and try to make adjustments to the retainer and spring after I've tested it. I just want to get it as close to properly fit as I can before I put everything back together. I just don't have enough experience yet to know how a "dry fit" should feel. Thanks.

 

I take the Pad Pin and hold it in the Vice.
Then, I "Shoe-shine" a nice smooth, rust-free surface on it.
When done; I "Smear" a light Coat of Synthetic Waterproof Grease on it.

On the Early Calipers that > Pivot < ... I clean and lube the Bushing-Bearing.
On Later Calipers that > Travel < ... I shine the Rods the caliper Travels on, Clean the Bores the Rods Travel in and Grease the Bore with Waterproof Grease.
( You have to squeeze the Caliper back on the Mount to BURP the Air trapped behind the O-ring.)

Lube the Caliper Seal, it's Seating Channel and the Caliper piston with Clean Brake Fluid during assembly.

 

Thanks, Rick. I cleaned everything up thoroughly, including removing any corrosion and polished inside the sleeve and the bore in the caliper that receives it. I'm quite certain that what is making it fit tightly is the spring pushing against the pad such that it's creating friction up where the pad tab sits in the retainer.

 

I took the bike for a 15 mile ride tonight and the brake feels pretty good. However, with the front tire propped off the ground, the wheel does not spin freely. It's not difficult to turn, but the outside pad is definitely creating some drag on the rotor.

I have not yet done anything with the caliper piston and seal, but I'm really thinking I need to play around with the spring clip and retainer. I just wish I knew how tightly the pad is supposed to fit into those.

 

After all you have done, ...

You should have ALSO ...

Removed the Caliper Piston.
Removed the Caliper Main Seal
Scraped-clean to Bare Aluminum ... the Caliper Main Seal's "Channel"
The slightest bit of foreign matter in the Seal Channel renders the Seal, ... "Out of Round".
If the SEAL is pushed "Out of Round" ... The Piston Binds.
When the Piston Binds ...
The Brake Drags.

 

Did you tighten the pinch bolts before you tightened the axle nut? If you did that's wrong. Tighten the pinch bolts last.

 

No.

 

Tightening the Pinch bolts after tightening the AXLE NUTS, sounds like good information to me. It's amazing the tricks a guy can learn in here if he listens to the problems others are going through. It seems like most of the time it's the simple mistakes that mess up a job but sometimes it's the things we never think of that the motorcycle repair shops if asked act all of a sudden like they don't know anything about it? I really appreciate the guys that write in with problems just about as much as I appreciate reading the responses from the Moderators in this room. It all gets stored in the back of my head for that Rainy day when I might just need another perspective on a problem I am going through with my own bike. grunt007, 81'XJ750SecaR, Mi. Keep up the good work guys, were all learning more day by day.

 

I hear you, Rick. Cleaning up the piston and replacing the seal is a good idea regardless. But can you honestly tell me that there's no way that the pad is just hanging up because of the spring putting too much tension on it? If that's the case, a rebuilt piston won't fix it.

You know WAY more about this than I do, and I'm not trying to be argumentative. It's just that no one is addressing my question about how tight the spring and retainer are supposed to make the pad fit.

Thanks.

 

On the Pivoting Caliper, the Spring and Retainer are "Light-pressure / Anti-rattle" devices.

The Caliper Piston needs Travel.
Not much; but enough for the Caliper Piston to recede when the Hydraulic Pressure is released.
As the Pads wear, fluid takes-up the space to keep the Pad close to the Rotor.
The Sight Glass on the Master Cyl indicates how much fluid has replenished the volume needed at the Caliper due to Pad Wear.

Just a little bit of Foreign Matter buildup behind the Caliper's Main Piston Seal will prevent the Caliper Piston from receding the "(my-nute)" distance is should to prevent the Pads from Dragging on the Rotor and disengaging enough to be fully released.

Brake Levers with Cross-head Screw and Lock-nut adjustment features which have been "Turned-IN" compensating for excessively worn-down Brake Pads, must have the Cross-head Screw adjuster brought-back out to release pressure on the Master Cylinder Piston to let the Hydraulic Pressure become neutral again.

 

Thanks for the reminder about checking the adjuster screw because I had not done that yet. That wasn't the problem, however. I still had a slight amount of free play.

I will do the piston job. However, for my own learning process I'm going to take the caliper off tomorrow and play with the spring and retainer. Could I learn anything by reinstalling it without the spring? I wouldn't drive it like that, but could I at least determine if the piston is receding far enough or would the pads be too loose for that test to be of any benefit?

 

You can even ride it (not for a long time or anything) without the anti-rattle spring if you need to confirm that you should have rebuilt the caliper to begin with.

(You should have rebuilt the caliper.)

 

Thanks, Fitz. I'm not denying that it would be a good idea to rebuild the caliper and, as I've stated, I fully intend to. I just really want to understand what makes for a proper fit of the spring and retainer. Is that so unimportant that nobody cares about it? Maybe it is, because no one seems remotely interested in addressing that. If I'm completely off base on this issue, someone needs to say so.

 

It's not that nobody cares to address it; heck we've been addressing it 'ad nauseum' for a couple pages now.

I'm not as intimately familiar with the "angle-swinging" 650 Max caliper as I am with the other types of XJ calipers. But generally speaking, the anti-rattle spring pushes against the upper corners of the pad enough to gently "bind it up" slightly, to keep the pads from rattling.

When "bench assembled" in your hand, the degree of bind applied by the anti-rattle spring CAN seem excessive; but once mounted on the bike and bled, and after some braking force has everything all nicely "squared up" you will likely find that the bind isn't as great as it seemed when everything was just kind of flopping around free.

Again, generally speaking, the anti-rattle spring won't produce enough of a bind to cause the pad to drag enough to impede free rotation of the wheel; however a STICKY CALIPER sure will. The pad doesn't move far enough for the anti-rattle spring to bind it up that much.

 

I took the caliper off today and removed the anti-rattle spring, pushed the piston in a little ways with a C-clamp, then put it back on the bike. Once I had brake pressure pumped back up, the drag on the piston-side pad was still there. The caliper piston was, in fact, not receding back far enough into the cylinder. I have ordered a seal kit and a new piston. The piston wasn't too bad but did have a few fairly deep pits, though only on one side.

Let the "I told you sos" begin!

As always, I truly appreciate the input that I received on this thread. Though there were a couple moments of mild frustration, I don't regret at all having gone through this process. I learned more about how this brake is supposed to work by really digging in and testing my theory than I would have by just rebuilding the caliper when it was first suggested. That I already knew how to do.

Thanks again.

 

I have a feeling you are going to find that your problem is a build-up of foreign matter within the Channel the Caliper Main Seal sets in.

Build-up in that Channel causes the Caliper Piston to fail to recede when the Hydraulic Pressure is relaxed.

The stuff is a combination of Brake Dust, Brake Fluid, Moisture, and Road Grime.
It hardens and adheres to the Channel Surface forcing the already close tolerances to shrink; plus renders the SEAL >> Out-of-round, ... making the Piston Stick rather than move.

 

Thanks, Rick. The channel was moderately crusty but I've got it pretty well cleaned up now. There's some mild pitting in the "corners" of the channel and someone previously put a few small scratches in the channel, too, presumably from digging out crud. It wasn't leaking before and I think (hope) it will seal.

 

Get the channels (especially the one for the main seal) as clean as humanly possible. A small brass wire brush in your Dremel works quite well, as does an assortment of scrapers carved from a bamboo barbeque skewer. For really persistent crud, you can gently hit it with the flame from a propane torch and turn it into more easily-removable dust.

Make sure any pitting on the piston itself is outside the area swept by the main seal.

And "No Saying I Told You So" is XJBikes LAW #2. So don't sweat it.

 

I'm satisfied with how clean it is. I used some small pieces of red scotch-brite pad. I don't have a brass wire brush for my Dremel but I'll have to keep my eyes open for one, plus an extension of some kind.

Piston pitting was not in a good spot so I decided not to chance it and ordered a new one.

Thanks, Fitz.

 

This thread has been excellent for advice on rebuilding the caliper. Once again, this site has helped me attempt things I never would have dreamed of with just the manual.

I'm just about to reassemble my caliper and I'm curious. I ordered the caliper rebuild kit from chacal, and it came with some red lubricant. Where is this lubricant supposed to be applied? You have said to lube the mounting bolt sleeve, and just a little lube on the pad retaining pin. Since the manual calls for "graphite or molybendum grease" on the bolt sleeve, can I assume the red stuff can be used on the pad retaining pin? Or is the red stuff just pretty decoration?

 

The red goo is brake assembly grease.......wipe a thin film on the rubber fluid and dust seal, the piston or caliper bore, you can use some on the slider pin and the mounting sleeve, etc.........just don't get any on the brake pads at all!

 

I truly hate to resurrect this thread, but after a full rebuild of my MC AND caliper including a new piston, my brake is still dragging on the pads. I have not yet ridden it since the rebuilds so maybe that will make a difference. However, I just propped the front brake off the ground to give the wheel a spin and I'm getting the same results I had before I started.

As you may recall, my questions were focused on whether or not my caliper's spring clip and retainer may have been causing one of the pads to hang up. After removing them both and testing, it was still dragging so I went ahead and rebuilt the caliper.

Now what?

Frustrating because I was planning to take this bike for a three day ricde beginning this afternoon. Thanks.

 

The caliper is not free to pivot on its pin, betcha.

 

Thanks, Fitz. I just checked that out. Loosening the mounting bolt does make quite a difference. The wheel will spin now although I'm still hearing a little scraping. The pads are brand new though so maybe a few miles will clear that up.

I'm a little confused, though. The manual says the caliper to fork bolt should be torqued to 18.8 ft. lbs. That makes it pretty tight and restricts how much it can pivot. Should I adjust to be more loose until I get more free movement?

 

Can't help you there, bud. All of my XJs use "holding block" style calipers (2 different styles though) so I don't have any intimate experience with the Max's pivoting caliper.

I thought that the assembly was such that with the bolt fully tight, the caliper could still pivot freely. You sure something's not slightly out of place, pivot-bolt/washer/spacer wise?

Somebody like MiCarl with some experience with those calipers needs to chime in.

 

That's my understanding, too, Fitz. I just tightened it back up to spec and took it for about a mile and a half ride and it seems a little better already. Maybe everything just needs to get "settled in."