front brake adjust

[deltarider]

Replaced my brake pads by ones with more meat. Now I can't get the front wheel to spin as freely as I was used to. Brakes worked well before and the release was also good. Should I have used this tool (pic) to push back the piston somewhat before fitting the new pads? And if I do that, do I then need to open the bleeder or the brake fluid container at the handlebar? I have read the manual about 'drag', 'halve a turn', '0,15mm' etc. but for some reason I don't quite understand what that caliper adjust bolt does or is supposed to do. Can there be something wrong with that bolt?

[Bryanj]

Yes you should have pushed the piston back, also remove the paint arround the outside of the pad.
It is also possible the seal groove is corroded and piston pitted which means a caliper stripdown

[Johnwebley]

As a quick thing,

Slacken the 2 caliper bolts

If you have a thin spanner, tyre lever,

Put it between disc and moving piston,

Tighten 2 bolts evenly

The piston should go into the caliper,

The brake fluid will just go into the  master cylinder reservoir

Remove bit of metal,
Tighten the 2 bolts

Spin the wheel, check the pad is not rubbing

Them pump the brake lever,until the gap is normal

If this doesn't work,

Check the post from Bryan


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[deltarider]

Thanks gents, appreciated. Yesterday clearly wasn't my brightest day. Later in the evening I thought of the same resolution John suggested.
It's winter and if needed I have still ample time for a caliper stripdown. But let me first check if I can arrive at the good working brake I had before. So far I didn't have problems with my brake.
Some 15 years ago an uncle (car mechanic) has honed where the piston sits somewhat. Piston was a bit pitted but according to him not that bad that it would need to be replaced.
I think there are two reasons my brake so far didn't need much work.
1) I never ride in rain, so less accumulation of dirt.
2) When in hibernation, say every 6 weeks, I roll my bike and apply the brake a couple of times.
A friend has another solution: he pushes the piston a bit back at the beginning of each hibernation.
Question: what can cause the pads wear like in the pic below? Should I maybe be more precise in aligning the activated pad to the disk or is the wear shown in the pic not abnormal? The reaction pad has that hump in the back, so that one will adept.
The pads are by EBC and as you can see, I chamfered them.
I had the disk of and I checked with a feeler gauge: no warp. In the international forum there's much talk about sanding the disk for improved braking. So far I have not read what with, like what # grit.
Any suggestions?

[Johnwebley]

Those pads look ok

The bit filed away is to stop squealing

Use A LITTLE  coppa slip around the moving pad and on the hump of the fixed pad,

Could also help

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[deltarider]

Those pads look ok

The bit filed away is to stop squealing

Use A LITTLE  coppa slip around the moving pad and on the hump of the fixed pad,

Could also help

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Ha! That's exactly what I did! I have this little 35 year old tube with coppa paste, and although the cap has been missing for more than 30 years, it comes out just as easy. Amazing stuff. I used it sometimes on sparkplugs threads and always on the two big bolts in the caliper and the 8mm studs at the bottom of the front legs.

[Sesman]

Did I read somewhere that the solution to stop brake squeaks is to shim the piston/ pad? Maybe a myth…

[Bryanj]

Yes a myth.
Slight pitting 15 years ago means a new piston now to me PLUS as has been discussed many times a new seal with the groove meticulously cleaned out.

As far as i am concerened brakes have to be perfect as we only have one neck to break

[Sesman]

For clarity, the attached is bollox?

https://motorcycleproject.com/text/brake_ills.html

[Johnwebley]

For clarity, the attached is bollox?

https://motorcycleproject.com/text/brake_ills.html

For clarification

On the 500,a nylon washer which fits between the pad and piston is often included with new pads

But what it does is a mystery,

I tend to find, the harder you use the brake, the less squeal you get

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[deltarider]

[...] On the 500,a nylon washer which fits between the pad and piston is often included with new pads
But what it does is a mystery, [...]

I suppose it is there to dampen vibration and - as a consequence - reduce sqeal.

[Sesman]

For clarity, the attached is bollox?

https://motorcycleproject.com/text/brake_ills.html

For clarification

On the 500,a nylon washer which fits between the pad and piston is often included with new pads

But what it does is a mystery,

So does the 550. I’, gonna give the recommendation a try using thin s/s sheet with corrugations.

I tend to find, the harder you use the brake, the less squeal you get

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[Bryanj]

A long read and a few points are not total bollox,
1 all the fours had the nylon washer from new and i think genuine replacements came with a new one but aftermarket didnt
2 discs warp due to heat but i have never seen a stainless, standard, honda disc warp
3 never ever seen a gasket between disc and mounting
4 silicone fluid can be used but only if the total system has been stripped out and meticulously cleaned along with new hoses, glycol fluid(dot 3) is fine when it is changed every 2cyears like its suposed to be(but who does?)
5 50 year old brake systems are definately not as good as modern ones, get used to it

[deltarider]

Good info, Bryan.
What would be your favourite fluid: DOT 4 or 5.1, both not silicone.
What is the best piston option, material wise? A stainless steel will not corrode, but could it be harmful for the caliper due to eventual electrolysis?

[Oddjob]

Just some points to consider.

Mike Nixon was a trained manufacturer instructor. When mechanics go on training courses he's the guy who's training those mechanics in proper procedure and the manufacturers thoughts on problems that the training was there to try and cure. Not only was he a trained Honda instructor, he was also a trained Kawasaki instructor IIRC. As such he'd have had access to information from the manufacturers that mechanics, even trained mechanics wouldn't. This I feel qualifies him to pass on this information which should be at the very least be considered for thoughtful consideration. Far too many people think that because it doesn't match exactly with they think that they should either ignore it or start to criticise it. I'm not saying his word is gospel, just that it should be seriously considered.

Some of the points raised may not be 100% Honda, some may be things which happened whilst at Kawasaki. I think he adds them just in case they will be of use to others reading his thoughts.

I personally didn't find it a long read, short in fact considering the subject matter. I've been on training courses that spent 7 hours on a subject that should really have been 2 hours at most and that would include a hands on training part.

As Mike says the nylon washer was fitted to dampen vibration . Where I think he went wrong was in his description of it as a gasket. What I think he was saying is that it's possible to fit an alternative where a washer that thick would be a problem, something much thinner is required and he found some plastic coated cardboard worked as well but didn't last as long as the nylon washer.

Same things apply to fitting a similar gasket between the disc and the hub, it was fitted to later models but not to the SOHC bikes AFAIK, it just dampens out the metal to metal vibration and may be of use to even some SOHC bikes, just because Honda didn't fit it doesn't mean it can't be of use. TBH not a point I had considered but worthwhile information I think.

I found the brake fluid page very informative, didn't consider going silicone myself but after reading his thoughts on the subject, especially the lack of use these bikes are subject to these days, it may be something that you should at least give some consideration.  All my brake parts are new so for me going silicone will be easy. However if you're one of those who insist on having original rubber brake hoses I can see why that might be a problem. However you now have some information that may make you feel you should reconsider that stance.

As for disc warpage, Bryan is correct, I personally haven't seen a SOHC disc warp but did see other manufacturers discs warp, Suzuki for instance. But they were later models, in the 80s for instance when discs were getting thinner and thinner. As Mike says, the lack of metal due to their thinness meant they overheated easily, this caused them to warp, hence why they started to mount the discs on bobbins, to allow this to happen but the bobbins would try and allow the disc to straighten out afterwards. As Mike says, it doesn't always work.

Interesting to note Mike saying sintered or ceramic pads work much better on these old stainless discs than the softer organic pads, these old systems were great back in the day but compared to modern brakes they appear to be really bad, getting them to work better and for longer whilst retaining safety is always a good idea. That may involve fitting a second front disc or maybe having them slotted or drilled, fitting different composition pads which weren't available back in the 70s, maybe fitting different lines like braided to try and avoid the expansion of the old rubber hoses, a different MC maybe, more fluid for less pressure? All points to consider.