SMC Thread Locker

Fawlty

Fawlty

Joined
Oct 26, 2017
Messages
327
Location
Murcia, Spain
Bike
Honda ST1300 Pan-Eur
Quick question, does the top bolt securing the SMC need to have thread locker applied?
 
Fawlty said:
Quick question, does the top bolt securing the SMC need to have thread locker applied?
Click to expand...

Technically, the Service Manual requires that all bolts securing the calipers to the forks to be replaced each time the caliper each time they are removed. New bolts come pre-coated with threadlock.

If you reuse the bolts and want to use a threadlocker, I recommend that you use Loctite 248 Glue Stick (here). It will lessen the likelihood that the threadlock itself will get into the needle bearing, which could impede proper SMC function.
 
Buckeyechris said:
Technically, the Service Manual requires that all bolts securing the calipers to the forks to be replaced each time the caliper each time they are removed. New bolts come pre-coated with threadlock.

If you reuse the bolts and want to use a threadlocker, I recommend that you use Loctite 248 Glue Stick (here). It will lessen the likelihood that the threadlock itself will get into the needle bearing, which could impede proper SMC function.
Click to expand...
The top bolt does not include a needle bearing but your suggestion is a good one.

Working on the lower pivot bolt or any bolt or screw that passes through a sleeve or bearing always apply thread locker ONLY to the threads of the nut or threaded hole the bolt goes into and not the threads of the bolt passing through the sleeve, collar, or bearing. A generous dot of Loctite Blue liquid thread locker on the initial threads is sufficient.
 
dduelin said:
The top bolt does not include a needle bearing but your suggestion is a good one.

Working on the lower pivot bolt or any bolt or screw that passes through a sleeve or bearing always apply thread locker ONLY to the threads of the nut or threaded hole the bolt goes into and not the threads of the bolt passing through the sleeve, collar, or bearing. A generous dot of Loctite Blue liquid thread locker on the initial threads is sufficient.
Click to expand...
I stand corrected :)
 
dduelin said:
A generous dot of Loctite Blue liquid thread locker on the initial threads is sufficient.
Click to expand...
Trouble with that Dave, is that I found that it flows easily, and as you screw in the bolt it gets channeled out and into into the sleeve - making it difficult to remove the bolt at a later date. There is no other danger - the bolt and the sleeve are clamped together anyway. But I watched the next time I put the bolt in - and somehow I got loctite on the outside of the sleeve. I just use the lipstick now.
 
Inspecting and cleaning the bolts with a wire brush and reusing seems fine for me.
I would let dry the (blue) Loctite before reinserting the bolt, just to prevent the liquid to flow everywhere.
Also, covering 3/4mm of the threads must be enough, too much could be a pain.
 
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jfheath said:
Trouble with that Dave, is that I found that it flows easily, and as you screw in the bolt it gets channeled out and into into the sleeve - making it difficult to remove the bolt at a later date. There is no other danger - the bolt and the sleeve are clamped together anyway. But I watched the next time I put the bolt in - and somehow I got loctite on the outside of the sleeve. I just use the lipstick now.
Click to expand...
You would think the bolt would block liquid thread locker from flowing backwards toward the sleeve and instead push excess into the interior threads of the nut. Maybe a little less thread locker would prevent this. The lip stick naturally controls the amount applied so there is no "too much."
 
Sidekick said:
I would let dry the (blue) Loctite before reinserting the bolt, just to prevent the liquid to flow everywhere.
Click to expand...
I have to wonder how effective it will be as a thread locker if it is allowed to dry before the two parts are mated. Liquid Loctite is intended to be applied wet and allowed to cure with the male and female threads in contact with each other.

I personally have never felt a need to use any thread locker on any part of any Honda that I have owned. I have never had properly installed fasteners come loose.
 
dduelin said:
You would think the bolt would block liquid thread locker from flowing backwards toward the sleeve and instead push excess into the interior threads of the nut. Maybe a little less thread locker would prevent this. The lip stick naturally controls the amount applied so there is no "too much."
Click to expand...

There is quite a gap between the ridges and troughs for the liquid. I put the locking agent on the bolt threads and when that is screwed into the thread in the bracket, it 'scrapes' the surplus and pushes it towards the sleeve. I can't work out how the fluid gets onto the outside of the sleeve, but I managed it somehow. Probably by using too much and being hamfisted. But If I managed it once .....

To answer someone else's question - I think the paste may set when it is deprived of air. The liquid is probably the same - otherwise it would set in the bottle.
 
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Willsmotorcycle said:
IIRC the OEM caliper bolts come pre applied with "lock tight".

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Those look like the screws fixing the rotors to the wheels not left front caliper bracket bolts but yes new caliper bracket pivot bolts do come with complete with a dry thread locker factory applied. If you reuse them instead of replacing them the comments in this thread apply.
 
Andrew Shadow said:
I have to wonder how effective it will be as a thread locker if it is allowed to dry before the two parts are mated. Liquid Loctite is intended to be applied wet and allowed to cure with the male and female threads in contact with each other.

I personally have never felt a need to use any thread locker on any part of any Honda that I have owned. I have never had properly installed fasteners come loose.
Click to expand...
If you replace any of these bolts with the factory one the thread locker is already applied and.... dry on them. Can you explain why it wouldn't work on used bolts the same way?
Just being curious there.
 
Sidekick said:
If you replace any of these bolts with the factory one the thread locker is already applied and.... dry on them. Can you explain why it wouldn't work on used bolts the same way?
Just being curious there.
Click to expand...
Liquid Loctite is designed to be applied wet and the parts assembled when the product is still liquid. What comes pre-applied on new bolts is not the same product.
 
dduelin said:
Those look like the screws fixing the rotors to the wheels not left front caliper bracket bolts but yes new caliper bracket pivot bolts do come with complete with a dry thread locker factory applied. If you reuse them instead of replacing them the comments in this thread apply.
Click to expand...
Yes, I was thinking to hard, it was in reference to pre applied and dry. Thank you Dave.
 
jfheath said:
Trouble with that Dave, is that I found that it flows easily, and as you screw in the bolt it gets channeled out and into into the sleeve - making it difficult to remove the bolt at a later date.
Click to expand...
I also found the excess in the bore attracts humidity (hence corrosion) later on...
There also thread lock tapes around, 238 VC-3, Loctite 1372603, etc...
Those and the Loctite 248 wax stick seem practical in such deep recessed applications...
 
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