How do you glue yours ? (Brake Retainer Clip)

[jfheath]

Do you glue your pad retainer clip in place ?

Hidden away in Honda Workshop Manual are a few tables - the ones that you thumb through rapidly in order to get to the Maintenance section. In there are various lists - all of the components that require Moly Paste; Silicone Grease; General Purpose Grease; Urea based grease; etc etc.

In that list is this single entry for the components that require the application of ThreeBond 1521 adhesive.



That is this little fellah (this one is for the rear caliper - the front looks similar).


And according to that table, this is supposed to be glued in position.

No. Me neither.

I had spotted the requirement for glue in the manual about a year ago. Coincidentally, Larry was working on a bike with an odd noise coming from the rear brakes that he couldn't pin-point, and produced a number of photos, one of which showed the retainer clip had dropped quite significantly.

Mine didn't show any sign of wear, so I looked at some photos of my previous ST. The photo below is one that I took of my ST1300A6 at approximately 60,000 miles for the article 'Avoiding the Pitfalls'. It shows the clip on the rear caliper bracket looking through the rear wheel from the right hand side. At the time I didn't notice anything wrong - I hadn't paid that much attention before.



The red line points to a gap, indicating the amount of wear that has taken place - not at the point where the arrow is pointing but on the bottom lip of the same recess. In other words, the clip and the brake pads have dropped. The position of the tag in relation to the small protrusion on the caliper bracket serves as an indicator of how much wear has taken place. This photo shows it has reached the bottom of the protrusion.

On the photo that Larry showed me, this drop was very significant - and we wondered whether the glue (or lack of it) has some part to play in this erosion.

It seems from some samples that the inboard side of the clip wears much faster, so the clip tends to develop a tilt. And it is possible that this sets up an oscillation as the brakes are applied and released. The movement will be very small at first - the clip kept in place by the recess in the caliper bracket, but is not locked solid. Over time the movements will become larger and wear rate will likely increase. I think that the application of the glue may stop this problem before it starts - preventing the retainer clip from moving and wearing down the recess in the bracket. At the very least it I imagine that it would provide a slightly flexible barrier between the clip and the bracket.

The recommended glue is ThreeBond 1521.


Techsil describe this as : a multi-purpose, high strength, fast setting chloroprene rubber adhesive. It is suitable for bonding a wide range of substrates including metals, rubbers and plastics, giving a high initial bond strength after setting.

The Amazon UK site lists the 1521 product, but it is currently unavailable, and they don't know when it will be back in stock. Which is usually short for 'we can't get it any more'. Other sites still list it, but if it isn't available, this could be old stock, and in my experience glue doesn't last forever, even in an unopened container. However, the Amazon.com (USA) site still lists it as being available.

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So I started looking for something similar.

The closest that I can find that I think may do the same job is Unibond Repair Extreme. It does not advertise itself as the rubber based adhesive of the 1521, but on the face of it, it appears to have similar properties. The image (right) and the description below - are both taken from the Unibond website.

Description:

A flexible multi purpose adhesive with patented FLEXTEC™ technology.
UniBond Repair Extreme will repair and bond virtually all surfaces and withstand the most extreme weather, whilst providing an outstanding bond even when applied in damp conditions.

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I haven't got a clue whether it is actually up to the job, but all it has to do is keep the clip from gradually abrading the recess on the caliper bracket. Even if the glue fails, the result would be no worse than the glue not being there in the first place.

What I don't understand is why it is not mentioned in the servicing section, and why the left front (SMC) bracket which comes with a clip fitted, does not have the clip glued into place.

Anyway, I'm going to give it a try. I probably won't know the results for another 50,000 miles - but it is just a heads up about the manual requiring that clip to be glued in place.

 

[RaYzerman]

Interesting... I did not know they should be glued, they weren't from the factory AFAIK. However, on my VFR (65k mi.), the clip in the right caliper had half of it missing. The cause was due to significant wear in the caliper bracket.... 10 times worse than what's in your pic. Fitted a new clip (not noticing this), wondered what the noise was a few miles later. Rotor was grinding away at the clip trying to saw it in half...... I bought a used bracket with virtually no wear and fixed it..... no glue.
The clip's tabs should provide enough interference fit to stay in place (no glue) and if yours is loose, maybe glue it to reduce vibrations and any worse wear on the caliper bracket.

 

[jfheath]

The clip's tabs should provide enough interference fit to stay in place (no glue) and if yours is loose, maybe glue it to reduce vibrations and any worse wear on the caliper bracket.

Thanks for that @RaYzerman.
I think that the glue probably would help reduce the chances of vibration and wear. But it's only a personal opinion based on not much evidence.

Mine isn't loose on my current bike. It takes a bit of effort to pry it free, and it seems to be firm. The comment comes about due to two things.
1 - The table in General Information Page 1-26 in my workshop manual says to use it.
2 - The wear that Larry reported on a bike that he was working on - my photo seems to show the first signs of it on my previous ST1300

I'm Just putting two and two together - possibly making 5. Possibly not.
I've always rubbed in some MoS2 paste in the recess behind my clips when I clean off the muck and salt deposits behind it, so that if it does move, it does it with the minimum of friction. Even so, that photo revealed the start of some wear.

I wish I could find Larry's photos. I must have them somewhere....
....Found them. Here's one.

 

[alfixit]

I am in the last stages of some major re-work on my brake system, and I read the "Avoiding the Pitfalls" article by jfheath. I was inclined to use the Three Bond 1521 that was mentioned in that article, as it seemed to make sense if it was mentioned in the Shop Manual.
I was able to find it after a search on the net, and it arrived yesterday (sportbiketrackgear.com). Now I am trying to figure out where the correct location is for the bracket after it is glued in place. When I lay the new retainer bracket into the slot it fits into, there appears to be a gap between the retainer and the slot (image 1) of about .020 in. That gap appeared in the photo on page 6 of the article also. When I put the caliper together with the spring pad, brake pads, and the pad pin, it was pushed toward the bottom of the slot by the pressure of the spring pad. (Image 2) Is that the spot that the retainer needs to be glued, or should it be positioned tight with the top? It seems like the rotation of the brake would push it in the direction that the spring pad would push it. If I put it in the wrong side of the slot, the brake pressure will probably break it loose.
Any thoughts?
Thanks again. The people on ST-Owners have been very helpful.

 

[Sadlsor]

Do you glue your pad retainer clip in place ?
<SNIP>
That is this little fellah (this one is for the rear caliper - the front looks similar).


And according to that table, this is supposed to be glued in position.

No. Me neither.

Guilty.
I never have, on any bike I've owned, but I also have seen the mention of it as you describe not only in the ST1300 service manual, but also in the Blackbird service manual. As you noted, it's in the front of the book, but not on the actual disassembly / reassembly section.

 

[jfheath]

Short answer. I haven't got a clue.

Long answer. I couldn't find 3 bond either, but there are a couple of others that are strong, flexible and have high temperature properties, like the 3bond. The one that I used is UHU Max Repair Extreme Adhesive. Comes in a small tube,

My belief is that this chrome retaining clip can move about, and probably gets muck under it. Over time it wears away at the alloy that houses it, and it is common to see the lower edge of that part worn at an odd angle. That photo from @Igofar in my post above is very badly worn.

I think that gluing it in place solves the same problem in three different ways: It stops the small bits of debris getting underneath and acting as an abrasive; it stops the clip from being able to move; and if it does move, there's a flexible membrane between the two parts two minimise abrasion.

I don't know where is the best place to glue it - on the bottom edge which is where it tends to wear most but which would put it out of position, or on the top edge, which is closer to where it should be, but which might result in it being dislodged pretty quickly. My plan was to take a good look at it when I had done another 5000 miles. I've done a Covid permitted 12miles this year - just to take it to the test centre and back.

Its going to be a long year.

I've done 120,000 miles to date on two ST1300s, and when I started this thread, it was just after noticing the glue requirement in the manual for the first time. Curiously, when I ordered a new precautionary SMC, it came with the clip fitted. It wasn't glued.

Looking at the tab on the clip that you can see through the rear spokes, the bottom edge of the tab is approaching the bottom edge of the raised moulding on which the tab sits. I've yet to investigate if that represents a serious gap. Your photos show this view. They are pretty much central. I'd glue the face and the two sides. I reckon that will be better than not having any at all.

I can explain to myself that there is a logic to having it glued. I believe my answer enough to have found the glue and applied it to all 3 clips. I haven't a clue if it makes a difference, and my explanation to myself could be entirely wrong. Given the amount of riding we can do in lockdown is zero - unless going to work, to the shops and for an MOT , it will be a long time before I find the answer.

By which time I will have forgotten what the question was.

 

[RobbieAG]

Like many others, I didn't know this clip needed to be glued. I always wondered why it would slip out while being assembled and reinstalled (rear brake). I ended up using a small piece of masking tape to hold it in place during assembly and then removed it once done. I'll make a note to glue it next time. I wonder if the purpose is to hold it in place long term (where it would need to stand up to temperature extremes), or just for the assembly process. That would help determine which kind of glue could be used. Thanks for sharing the info!

 

[Sadlsor]

Prior to this discussion, I had always just a$$umed the brake pads keep the retaining clip / spring in place once properly a$$embled.
I have been accused quite often, of over-thinking things.
Now look what you've done!

 

[mello dude]

I have been accused quite often, of over-thinking things.
Now look what you've done!

Ditto for me -....Glue?????? (dammit)

Every Honda rear brake in the universe has that rear brake style....

 

[jfheath]

It didn't matter for 120,000 miles, 'cos I hadn't read it until then. But now that I have .....
Dangerous thing, reading

That would help determine which kind of glue could be used.

Well the quoted glue is ThreeBond1521.
So I tried to find something with similar spec. Couldn't find the Unibond I suggested may be OK in post#1, but came across the UHU.
All flexible, all high temp, all extremely strong, all suitable for metal, all suitable outdoors.

Threebond is a ?? chloroprene rubber ??
Unibond is ?? Flextec ??
Uhu is based on ?? UHU polymer technology ??

So that clears that up.

No, me neither.

 

[dduelin]

If I'm not mistaken, HondaBond 1521 was superseded by HondaBond A, which has been discontinued since 2012. Honda no longer sells an equivalent.

FWIW, the three Honda Service manuals I have on the shelf, ST1300; GL1800; and NC700X, all list an adhesive for the brake pad retainer clip or "clip retainer surface" in the lubrication and seal point sections but in the respective sections on caliper disassembly & reassembly they do not mention any adhesive use for the clip or caliper surface it bears against.

Personally I wouldn't glue it in place.

 

[Whooshka]

Uh oh.... oil, tires, moly and now glue. Earth is gonna spin off it's axis and fling us all into space.

 

[SMSW]

I'm guilty as charged - a non gluer. How long does it take for the glue to set? If you apply the glue to the clips, slide them in position, install the pads, and slip the caliper on the bike and bolt it down, would not the clips assume the proper position? And does not the glue set up after everything is assembled?

 

[SMSW]

Uh oh.... oil, tires, moly and now glue. Earth is gonna spin off it's axis and fling us all into space.

Unless, of course, you are glued down. You saw that one coming,I'm sure.

 

[jfheath]

I'm guilty as charged - a non gluer.

Yes - me too. Then I saw it in the Lubrication and Seal Points section of Chapter 1 - General Information of HW Manual. And I combined that information with a photo @Igofar posted (Copy in Post #3) where the seat for the said retaining clip had worn away. I put two and two together. Certainly, I have never seen mention of it before. But time will tell whether or not the answer was anything close to four.

I don't think there is a right and wrong here. If there is, I've been doing it wrong for years. Maybe the only real advantage of gluing it is that it is less likely to be lost and forgotten when an absent minded service engineer doesn't notice it fall onto the floor.
I don't know. I thought I'd give the glue a try.

How long does it take for the glue to set?

The Uhu version grabs pretty quickly, but remains moveable for about 5 mins.

Uh oh.... oil, tires, moly and now glue.

Now, now sir, behave yourself, or I'll tell you that prior to this experiment with glue, in order to minimise the risk of wear due to the small movements of the clip, I always burnished the recess where the clip is seated with Moly Paste so that the potential for wear was limited.

I think I'll go and hide now. Question: Is it possible to ignore your own thread ?

 

[RobbieAG]

When recently replacing the rear tire, I decided to try gluing the retainer in place. I used an automotive emblem adhesive (maybe I shouldn't have used that). Since doing so, I've been having trouble with the rear brakes making noise and the rotor getting very hot. I took the pads off, removed the glue and reassembled. It's better but still an issue. It may or may not be related, but I've had to ground the bike (good thing I have a second bike!) until I figure out what's going on.

 

[jfheath]

Might be as a consequence of refitting the wheel and the pads.
Take a look at

Article [13] - ST1300 Maintenance - Brakes- Avoiding the Pitfalls | ST1300 Articles

A close hands-on look at the Honda ST1300 braking system. These are personal observations about the things that can go wrong, why they go wrong and what can be done to keep things working sweetly. Updated April 2020 and to address more recent observations, to include information about the SMC...

www.st-owners.com

Read through it, there may be something in there that hits the spot.

There is @Igofar's discovery about the signs of a bracket mis alignment - the spiral 'rifling' of the hole where the stopper bolt fits.