Just realised I’m going to need 12 valve stem oil seals! Triumph original around £12 each (ouch)...other options on eBay £3 each, as pictured below! Any experiences with non-original seals welcome, but...and here’s the question: In the Haynes Manual is says ‘note, the seals are different sizes for the inlet and exhaust valves!’ However, WOT and Fowler’s and the eBay listing only appear to offer 1 size? What’s the consensus out there?
Another question: am I right in thinking the grease that gets put on the valve stems during the rebuild, is the only grease it ever sees?
The eBay seller has said the seals are to fit valves of 5.5mm Not sure where that leaves me with the Haynes Manual reporting as below, and the parts diagram from WoT and Fowlers only showing 1 type of seal?
Does anyone know whether “T3990067 | Gasket kit cylinder head” contains the 12 valve seals? I can’t seem to find the contents of it anywhere.
My 2p worth Stuart, I’d use original ones. I know it’s a heck of an expense but you buy cheap you buy twice in my experience. I’ve replaced stem seals on a Z650 a few years ago and used a fine smear of copper grease on assembly. By definition that’s all the lubricant that the stem will get if the seal does it’s job. If you haven’t already bought the grinding paste and suction tool I have both which I’ll likely never use again so if you want them FOC PM me your address and I’ll pass em on.
With the tiny difference between the stem dia i would suspect they have taken the one size fits all approach with the stem seals as they are stretchy anyway so doubt it would make any difference. And i always oil the stems before fitting there will be some seepage past the seals during use .
Blimey, that is SO kind, but I already went ahead and bought the grinding kit before Christmas, when I expected to be doing the job...but truly appreciate the sentiment all the same. It’s the strangest thing, but I’ve willingly spent £140 on 5 Torx tools, yet really recoil at £150 for the seals for some reason. I’m even considering reusing the old ones, but can’t decide whether buying non-OEM seals is better than doing that...such a dilemma. I hadn’t intended to buy the gasket kit, but if the kit contains the seals it would represent a saving...will check it out. Many, many, thanks again!
That would definitely make sense, just odd that the Haynes manual draws attention to there being 2 sizes, albeit that they describe them wrongly when saying the inlets are slightly smaller? Very strange!
Well its literally 9 thou difference so making a seal with that tolerance is not going to be easy so if it was me i really wouldn't worry about it ...don't know why Haynes are bothering as I doubt there will be any actual difference in the size of the genuine seals even if they say there is....just maybe the price.
What would be your thoughts on reusing them, especially if the valves were all carefully deburred before pulling out? It seems excessive to have a seal, that a valve ordinarily slides up and down in, defined as disposable when the valve is removed from it? The bike has done 29k...I’m seriously toying with the idea of reusing them, what’s your own take on it? Perhaps 29k is a good time?
I have reused plenty of car valve stem seals, but they need to be a reasonable condition not slack or nicked, the change in guide materials used these days is tailored to use stem seals, the high depression at low rpm will suck oil down the guides if the seals are bad. I would reuse them, put it this way if the seal will hold the valve from dropping out the guide with no lubrication they should be OK the only thing that will happen if they are not good is the odd puff of smoke when you roll on the throttle after closing.
Just to add, I’ve spoken to Fowlers who tried to find out for me without success themselves. Fowlers sell the valve stem seals for £8.75 (vat inc.) which is significantly cheaper than WoT (as are all their parts), but that’s still £105, which makes me think they wouldn’t be included in a head gasket kit that costs £168? Having to wrestle with my financial conscience now!
I would be very surprised if a head gasket set did not include the stem seals and if it's that price I would be kicking off if I didn't get them included!
Like tricky I’ve reused valve stem seals in the past on both bikes and cars and had no problems I’ve done loads of head jobs in the past and normally but not always the seals come with the top end kit
@Tricky-Dicky and @dilligaf Many thanks, gents...I’ve got a couple of emails out to other companies that offer the kit for sale, plus I’ve now found someone offering the entire set of seals for £30, so options are opening up. I’m SO tempted to run with the old ones though...it must easily be possible to push the ‘lip’ up from inside by using a valve and giving it a good old inspection. Their service life must extend well beyond 29k, surely?
Wait until you get the head gasket set and see if they’re in with it If they are If they’re not But I would use them again
Just to answer this question for future enquirers: “Thank you for your email and enquiry. We can confirm that the Gasket Kit Part T3990067 includes 12 x T3990004 Valve Stem, Seals. Gasket Kit T3990067 is in stock and available to purchase through your local Triumph Approved Dealer. Thank you for your continued support of the Triumph Brand and stay safe. Kind regards, Louise Triumph GB”
Hi Stuart T595, I've only just logged on to the forum, I would definitely not re use old valve stem seals, what takes place over time is two fold (1) the seals go hard over time and once removed microscopic cracks are evident, this risks minute particles of the seal becoming dislodged and working their way into the engine (2) the inner contact area 'valve stem to seal' wears and risks oil draining back down the valve and into the combustion area. Again I would only use OEM parts on any engine rebuild, having taken the time and effort to rebuild an engine I wouldn't want it to fail, I'm not saying it's wrong to either re use certain parts or buy pattern engine parts but it's a case of "cost verses risk". I can also confirm that the OEM gasket kit includes the valve stem oil seals. Ride safe all
