Caliper Bolts and Slider Pins

Can anti seize be used on the caliper slider pin bolt threads and caliper mounting bolts? Should I use loctite on any of the caliper bolts like the mounting bolts? What should the slider pins, caliper mounting bolts be torqued to? Any advice or tips on rebuilding them?
Thanks

 

Yes you can. Use anything that will not eat the aluminum or metal on there you want to loosen them up and get them out of there. After you get them out just clean them up really good to stop the reaction of any chemicals you may have used. I use BP blaster but almost anything will work. Keep working on those pins with the penetrating oil and work them a little with a long nose pliers or something that will get in there. Once they are out, clean them up, using a wire brush/wheel on them to clean them up and get any rust or pitting out of them. If they are too bad, you will need new ones.

I am sure someone has a link here for a good rebuild thread. Good luck.

 

Do not use anti seize on the slides for the caliper. antiseize is a mixture of small bits of metals, and is inteded for use where the bolt and threads are tightned once, and left alobne. if you use it on the slide end of these pins, it will slowly eat at the pins and make them extremly loos fitting.

antisiez is ok on the threads only, and use a high temp caliper type grease on the actual slides.

After you have them cleaned with a wire wheel or brush as @Timbox has suggested, clean out the caliper slide holes as well and re-lube them and insert the pins, noting any side to side "tweaking" movement. they should be fairlt tight on the side to side movement, but freely moving in and out.

 

+1

I prefer using medium strength locktite on the caliper mounting bolts, even if you still have the lock washers (for some reason they seem to get lost off several of the bikes I've worked on before I've ever touched the bike). The Locktite will fill the air gap inside of the threads and prevent corrosion (which the anti-zeize does too) but also prevent the bolts from backing off until you want them too. Generally I reserve anti-seize for areas that get really hot, like the exhaust nuts.

The caliper mounting bolts are torqued to 32 ft lbs
The pad retaining bolt is torqued to snug (finger tight and a tad more. Don't forget the retaining clip).

IF you haven't gotten a Haynes service manual, do so. It will save you from having to ask for torque values and waiting for the answer. The Yamaha manual is also available as a .pdf directly from Yamaha.

Part of why you won't find many how-to threads about rebuilding brake calipers is because the service manual covers it very thoroughly.

Some brake pads have undersized holes for the retaining pin. Just use a file to open the hole up.

While your model does not have the anti-dive, or the remote master cylinder, they are a bit fiddly to bleed properly, so this thread may be of use to you.
Bleeding the XJ750 Seca Front Brakes

 

I also only use locktite, but it is important to use the correct strength, as the red stuff can and has pulled aluminum thread right out. makes me UGHH!


use the blue on any aluminum threads, it hold just as tight, but is "releasable"

 

The red stuff is wonderful so long at it's used in areas where you can heat it to the 400ºF required for it to be removed.
Basically only use it on things that might need to come apart once or twice every 30 years, but preferably on fasteners that won't ever need to come apart to service anything.

And you can get away with not reapplying the blue every time a fastener is removed, but it's good practice to clean it off and reapply unless circumstances prevent that.

 

I used anti-seize on my muffler of my Mac 41 5 years ago and I undid the muffler of the other day and it slid right off. Absolutely amazing.

 

Their is a new Loc Tite it is orange. It holds as tight as red but is removable as blue Loc Tite.

 

Thank you all for your help.

 

Ok, dumb question. does the caliper piston go in with the solid end first so you see the open/hollow end when you look at the caliper?

 

Yes!

 

Thanks.

 

Any suggestions on getting the piston in even? It keeps going in crooked. I put a socket in the open end that fits pretty close and pull it down with a c clamp but is not even.

 

Less then 2mm but not straight. I've tried a few times and always comes out this way.

 

A socket with a c clamp might give a lot of downforce but it isn't very controllable, there will be more force on one side than the other causing the piston to do what it does in your case. I just used the plastic coated handlebar of a pair of pliers to put force on the edge of the piston, easier to correct.

 

I use a piece of metal bar the roughly the width of the piston and 300mm long so I can push down evenly with both hands, works for me.

 

Same method, better tool!

 

lube the seal and piston lightly , brake fluid will do the trick

 

these work well and are under 10$ most auto parts stores have them

Lisle - LIS24400 - Caliper Piston Compressor Tool (ecstuning.com)

you drop a socket into cup and use tool to push it in .
I have an aluminim slug i use instead of a socke with edges rounded and smaller than cup
you could use a piece of flat bar (brakepad with pad removed).

 

Loctite 242 blue is good for things you will need to remove from time to time, medium hold 222 is low hold lavender color. I just finished a two stroke single and after test riding it "everything" seemed loose so out comes the 242 loctite.
I use the made for disc brakes grease. My favorite grease is the Moly-bendium types, fairly expensive but a little goes a long way.
Cheers, 50gary

 

Thanks for all the suggestions. I'll give them a try until I get it flush.

 

That is even better. I have a wind in set for rear calipers which use for handbrakes on cars.

 

do you have a 6" or larger bench vise?

 

Ok. I tried all suggestions. I even remembered I had a caliper piston tool (a lot ofsearching but I found it). Nothing worked, it still wants to be high in the front. Any other ideas? The pistons and seals are brand new from Len (xj4ever) but still no go.

 

No bench vise but might have access to one. What would it be used to do?

 

Would you be able to use a G cramp?

 

take it out and see why it can't go flat, the bottom of the bore should be flat. could the bleeder be in the way?
if it all looks good lube it up and get a bigger hammer

 

Idk man, would the piston really go that far into the bore if it was cock-eyed? Think about it. I could be wrong though.

 

I tried a c clamp and socket to try and get even pressure and tried c clamp without socket and moved as close to the front as possible and still too high. It seems like the back bottoms out and the front won't go anymore. No bleeder in the caliper, its all apart. I used caliper grease on the piston and in the bore and the bottom of the bore looks flat. I could mic the piston and see if its even but no matter how I spin the piston its always out in the front.

 

take the seal out and it should just fall right in,flat, yes, no, maybe ?

 

To be honest, when I rebuilt my calipers (xj750) they did not go in completely "straight" meaning, like yours, when they were bottomed out they didn't sit completely even all the way around. I don't think the castings are "flat". I could be wrong.

 

I removed both seals and dropped the piston in and it's high in the front, exactly the same as with the seals and just the picture I posted earlier. I put the piston in the other caliper and it was the same high in the front, flush in the back. I then put the old piston in both calipers and it was the same way. Is it possible the front sits high and made this way? It would seem odd to me that both calipers would be bad in the exact same way. Thank you all for your help.

 

if you were to push the high side till it touches and the piston was now straight, would the whole thing fit back on ?
maybe you don't need that last 2mm

 

Not sure I understand. I have to wait to put the calipers back on the bike because the forks are off and the front end is apart. I'll put the caliper back together with the front being high and see if it will slide over the rotor if that's what you're referring to.

 

yep

 

I'll put it all back together with the pads tomorrow and slide it over the rotor and post what the results are. I would think it would slide over since the piston will be as compressed as possible. I'm concerned about braking, the pads wearing even and not ruining the rotors. Thank you everyone for your help and advice.

 

the bench vice will allow you a straighter insertion, and will prevent the piston or caliper from inserting crooked, and wont "pinch" the seal.

First you lube the piston seals in the caliper with some good grease, I recomend the grease in the link below, its what I use. Then you place the caliper into the vice, align the piston straight, insert a long deep well 1/2" drive socket into the piston face, then slowly tighten the vise.

it will insert smooth and you dont have to use much forct to do it. once you get the piston past the two seals, it will push in the rest of the way like butter...

This grease will not contaminate the brake fluid..

https://www.amazon.com/GENUINE-Corr...ocphy=9016171&hvtargid=pla-568759645110&psc=1


NOTE: the piston will not always go fully into the caliper, some models I have rebuilt hav about 3 to 5 mm still sticking out. this keeps the mating surface of the piston out far enough to align with the pad face.

Push it in till it stops and no further.

 

I looked closer at the piston bores and the back is deeper than the front of the bore and the rim above the outer seal is thicker than the front rim. I tried to measure the thickness and it looks like the back is approx 3.2mm and the front is approx 1.8mm. I dont see any way for these to lay flat and don't recall how they were when I pulled them apart.

 

You know, there should be no reason to push the pistons all the way in or make any contact with the back of the bore. They only need to be straight when contacting the rotor. Push it in squarely, not all the way in, and call it a day. Once mounted and bled there will be a fluid filled gap at the backside anyway.

 

The castings are machined before being ready to use. The back of the bore is square with the bore. The outer face of the casting has a radius to it.

 

I had old FJ 600 calipers and the piston protruded slightly like the one in the picture.

 

So, the back of the bore is not a raw casting surface but is also machined? Didn't know that for sure.

 

The entire bore is machined out of the casting (there may be a hole there already, but it will be undersized), along with the other passages. Even the outside of the casting is machined where the mould line is, and for the mounting and sliding surfaces. Raw castings are almost never good enough to use without being machined first.