Shelf life of oil seals.

[Dave B]

We are all much too familiar with the fact that the oil seals in a motor lose their flexibilty and leak after an engine lies idle for years,  but I've never really thought about this aspect before.
Do brand new, genuine Yamaha oil seals deteriorate on the shelf, in their original packets?
I've been asked to make recommendations on the rebuild of an RD400 motor, which comes with a full set of new seals and bearings (including the Labyrinth seal in the centre of the crank, which will not be a problem).
The thing is, that I suspect that these seals could be thirty years old.  
Has anyone got any experience with using what is a treasure trove of 'new, old stock' seals?
Experienced engine builders, what would you recommend?

Cheers
Dave

[chrisg]

Ive no experience of this, however I would get 2 new crank seals at the very least, probable £25. If you have to pull the engine out due to seal failure again, you may be a bit disgruntled. (read pi*sed off).

[midlifecrisisrd]

Unless the seals come in an original clean Yam bag new enough to have a barcode you would probably be fine but for the sake of 2 seals I'd buy new

Steve

[Tobyjugs]

Ive worked in some proper shit holes where i've had no choice but to use 20-30 year old rubber type spares. They will work, the problem will be for how long ? I have never cared in those instances as i was glad to get away and as long as it works for the first 6 months i don't get any come back from leakages etc.

If really old and in a critical build part of the engine try to get new parts. If not so critical advise it could leak but it is also an easy job to replace, let them decide?

[steeley]

Jun 3, 2022 9:23:40 GMT 1 Dave B said:

We are all much too familiar with the fact that the oil seals in a motor lose their flexibilty and leak after an engine lies idle for years,  but I've never really thought about this aspect before.
Do brand new, genuine Yamaha oil seals deteriorate on the shelf, in their original packets?
I've been asked to make recommendations on the rebuild of an RD400 motor, which comes with a full set of new seals and bearings (including the Labyrinth seal in the centre of the crank, which will not be a problem).
The thing is, that I suspect that these seals could be thirty years old.  
Has anyone got any experience with using what is a treasure trove of 'new, old stock' seals?
Experienced engine builders, what would you recommend?

Cheers
Dave

Hi , an interesting question . Some years ago i was in a trade counter of a hydraulic company / seals /hoses ect . I asked the chap about seals as i understood they had the kit to make them . He said yes we make seals and store them but then told me the story of an incident they had where a regular customer bought a seal /new and it promptly failed causing expensive damage . This caused an audited /self of this company and he said they skipped the majority of their stock . So i think they make/hold fast turn over stuff and just make other stuff when someone calls in .

[Dave B]

Thanks Steeley, That's the sort of information I was hoping for. I am already determined to recommend new seals anyway, but you have given me the evidence to justify that decison.
Cheers
Dave

[chrisg]

Jun 5, 2022 9:53:39 GMT 1 Dave B said:

Thanks Steeley, That's the sort of information I was hoping for. I am already determined to recommend new seals anyway, but you have given me the evidence to justify that decison.
Cheers
Dave

Kickstart,gearchange,sprocket seals can be changed relatively easy enough. The crank seals can be changed but it an all day job and would cost more in reacement gaskets,so why would you not is my question.