Damaged inside forks, will the seals work?

[spankysherlock]

Hey guys,

new to the forum.

Been meaning to join for a while as I thought about showing my rebuild in stages. Bought this bike a few months ago for winter project. (Had many bikes and learn as I go)

I got a 1968 Triumph T120 hardtail, it has a raked HD front end with chopper forks (Showa Japan).
Its one of those bikes that every single thing you open or check there is an issue..

When I drained the front forks about 2 drops came out, they were bone dry. Seals were F##ked, missing O rings etc..
Bought new seal kit after tracking down what part is but hesitant to install them yet.

It seems in its previous life someone has chipped away to get seals out, there are some indents inside where the seals will sit.

I have attached pics and interested to hear anyone's opinion as to whether they will seal okay? Or If anyone could suggest a good option to increase sealing? I'm wondering if there is some kind of sealant I could add to fill those indents before adding my seals.

Appreciate any useful advice on this!

Cheers

[Hawkstone]

They'll be fine. The seal is formed on the outer circumference, against the side of the leg.
Points scored for attaching pics.
:clap for you

[Tattooo]

Yes thank you for the pics...... They are very helpful....

[spankysherlock]

They'll be fine. The seal is formed on the outer circumference, against the side of the leg.
Points scored for attaching pics.
:clap for you

Nice one!

Thanks for the info, was already worth joining here

[Dougtheinternetannoyance123]

Until I saw the pix, I was thinking you were talking about gouges on the fork tubes themselves so was going to say "Hell no it wont work!" But I now see that you are talking about in the alloy on the sliders. Almost nobody does it here in the US on a motorcycle fork, But in Industrial applications here in th eUS and some places in other parts of the world for MC people will recondition fork tubes. Straighten them, strip them and plate with industrial hard plate and then precision grind back to spec size. Most people just buy new fork tubes.


Id gently dress the gouges to make sure theres no burrs, or bumps to make sure the seal fits all the way down. Does not look like its a problem on yours much, but if you run a blade or straight edge around the seal land, if it catches at all it might not let the seal sit fully home. The walls of the slider tubing look good so no issues there?

The fork seal seals in 2 dimensions, OD and ID. There a lip, or multiple lips if a good seal that seals the fork tube OD with the ID of the seal, but the seals OD on that type also seals against the wall. Some are full rubber/nylon/nitrile or other material but most are coated metal. For extra security there is a non hardening sealant called "HYLOMAR" and was created in the UK for aerospace apps, but was made under license in the US by Permatex. Its hard to find in most auto parts type stores but you can find it online.

That stuff works AMAZING! Its not like regular sealants or RTV. It wont work on the sliding seal, but it can help seal the rest. I use it on some seals and O rings and even years later it is still pliable and still sealing. (A really good use is pushrod seals on British bikes and HD v twins where they typically weep or leak oil.)

Sounds like your bike has a bad case of DPO-Dreaded Previous Owner. TRUST NOTHING! Id look up if you know what year it is and double check all the parts diagrams and make sure you have the right parts and nothing is missing or in the wrong spot. One of the interesting joys of old machinery is opening them up and finding out its either A) Full of junk, or,,,,,,,B) Once in a while finding brand new or high dollar upgraded parts inside - EUREKA! Always a roll of the dice every time.

(Good job with the pix illustrating your issue!)

[10scDust]

On the outside diameter of the seal, when questionable, I have used a light coat "Indian Head" gasket shellac.
Otherwise, lightly lubricate with oil, and seat them in.
I am going to look for some of that Hylomar by Permatex which Dougtheinternetannoance123 mentioned.
Always nice to have an array of choices, as a situation presents itself.

[Dougtheinternetannoyance123]

I am going to look for some of that Hylomar by Permatex which Dougtheinternetannoance123 mentioned.
Always nice to have an array of choices, as a situation presents itself.

Sealants are a complicated topic in some circles, almost as contentious as "What oil is best?" threads....

As one of my instructors said in Aviation school:" Gaskets are for sealing and RTV is for fucking it up"
So, use caution, nothing screws up engines more than over enthusiastic use of sealants.

That being said, theres a variety of sealants that are useful but IMHO none are universal.

Many people like the 3 bond or 4 bond products, Yamabond, Hondabond and others. My experience with them is they often work but most SEEM to solidify up into a very hard material and it takes a LOT of cleaning to remove them. (I have been using these 3m type pads on a shaft in a drill or die grinder)

I have seen some references to a 3 bond type product that allegedly does not harden like that, but have not tried any of it.

" There is a great bodning agent readily avalible at any Subaru store. Its called 3bond. Subaru reccomends this for all engine assembly. We use it on Subaru motors both fuel injected and turbo. It never hardens but seals like crazy. Subaru suppies it for gluing both crankcase halves, cam boxes, both where there is excessive heat or just normal engine running temps. You can dissasemble parts 3 bonded together at anytime with little effort. It can be cleaned off without much difficulty. 3bond runs about $17.00 per tube and one tube should take care of an entire Ferrari motor. One thing to remember with any sealant, a little goes a long way. No need to slather it on and have it squeeze out of every seam. 3 bonds has worked for us for many years with no problem what so ever."

However, As I said, I like Hylomar, But the permatex version is hard to find, story I heard was they discontinued it, but then brought it back?? I have since been buying other versions on Amazon and other sources online. Some works better than others. But its worth finding the good stuff.
I have used it on primary covers for Triumphs-BSA as well and a very light coating on both sides of the gasket,, I true the surfaces (Fine grade sand paper taped to a sheet of glass and some oil) and then its as true and flat as it can get, then lightly coat both sides of the gaskets. Same with pushrod tubes o-rings and seals. Rocker box seals and other joints that seem to weep. (Address the crappy breather systems to solve the primary cause).

Heres a good explanation on Hylomar:

" Permatex discontinued their version of "Hylomar" a few years ago which is good because it sucks compared to the genuine article which is still available.

http://www.hylomarusa.com/

I gotta disagree with the other posts regarding the silicone-based alternatives. Be aware that all silicones eventually breakdown when constantly in contact with hydrocarbons (e.g., gasoline and motor oil). Hylomar's main advantage is that contains no silicone and is impervious to hydrocarbons.
&
"Hylomar" is a registered trademark. The original formulation was developed by Rolls Royce many years ago for their own private use, and then it was spun-off as it's own, commercially available product ---- the link I posted is for this product.

Over the years, the name "Hylomar" has been licensed to several companies (including Loctite / Permatex) for use on their own products manufactured in general adherence to the Hylomar recipe. However, at least in the case of Permatex, the formulations are not identical. And, when you have used both (as I have), you can notice significant differences in their performance and shelf lives.

I have simply had much better results with the true Hylomar product. The only plus side to the Permatex version was that you could run to your local auto parts store and pick up a tube in a hurry (when it was still available). And, I always thought it was fine for less-critical jobs or jobs where you weren't tremendously concerned about long term performance.

Hylomar (again, I refer to the original) is actually available in variety of flavors for different applications --- including a non-setting, solvent-free type that has the same "get time" advantages of the Permatex version.

Also, I would add that when I contacted the folks at Loctite / Permatex about 1 year ago to inquire why I could no longer find their "Hylomar" at my local stores, they informed me that the final batch they produced was back in early 2005 --- and that they regarded any product still remaining on store's shelves to be "expired".

So here's the deal...

The original Hylomar is harder to find ---- speed shops, some specialized foreign auto parts stores, and online are likely to be your only sources. It is also considerably more expensive than the Permatex was.

But, trust me folks... it is worth the extra effort and expense... you will be very glad if use the original product. And, check out their website ---- you'll find that the original stuff is OEM for many impressive manufacturers (including our beloved Italian auto maker )."
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So again, do your research and also be careful HOW you use sealants (more is NOT better) but in certain applications some work really well.

[spankysherlock]

You guys above have given me some excellent advice here! I really appreciate the time you have taken to explain about these sealants..

I knew this bike would be a real mission when I bought it but thats why I bought it, I missed getting hand dirty and learning new things!

I loved my old Roadking but apart from basic maintenance and polishing there was not much to do.

I'll start a thread with my progress and pretty sure ill be back with more questions at some point!

Until then have a great Christmas guys