jfheath
John Heath
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.
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.
------

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.
-----------------
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.
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