oldbilbo
...
I'm not! Some numpty has left an oily rag in plain sight.....
And is that black circular thingy there to waft the smell of fresh-baked bread and good coffee through the bilges?
Dripless shaft seals
- Thread starter robertj
- Start date
I'm not! Some numpty has left an oily rag in plain sight.....
And is that black circular thingy there to waft the smell of fresh-baked bread and good coffee through the bilges?
robertj
Well-Known Member
Oldbilbo is Brian at Aquafax?
charles_reed
Well-Known Member
I am duly impressed with your faith in stainless (or bronze) springs - I've yet to meet one that doesn't, in the fullness of time, get tired - just like a nitrile bellows
Kelpie
Well-Known Member
I-spy with my little eye... a rather awkward CAV filter...
rotrax
Well-Known Member
I am impressed with the simplicity of the Volvo/Radice type seals.
They use no springs at the sealing end but have long soft twin sealing elements that are held to the rotating shaft by water pressure-well the inner one is-no water should get by that but if it does there is one in reserve.
They are a great step forward from the Victorian technology adjustable gland sealed with a bit of string, more reliable than face seals and cheaper than both.
I have yet to hear of a correctly installed and sized one failing prematurely, and personally have used two for a period in total of seven years without any problems. I am looking forward to many more seasons from the one fitted to Jess.
When I change I might go the the Radice with a breather tube-or I may add one to a Volvo seal. Something like a threaded motorcycle tubeless tyre valve but in 316 SS sould do the trick-I can bore out a 6mm SS screw on the lathe and use a good sealer. Choosing where to put the hole would be the main concern.
Food for thought..............
vyv_cox
Well-Known Member
I'm not! Some numpty has left an oily rag in plain sight.....
And is that black circular thingy there to waft the smell of fresh-baked bread and good coffee through the bilges?
It's actually a tin containing the pump front cover, impeller and six screws. The sharp eyed observer will note that the pump drive belt is loose, as are the bolts that hold it on.
vyv_cox
Well-Known Member
30boat
N/A
It would be from forward but could hardly be easier from aft.
I think your Aquadrive is missing...
robertj
Well-Known Member
I've discovered that my shaft has a little wear from the packing gland, does the pss need a perfect shaft or is there a little tolerance when the stainless collar is locked on?
bert49uk
Well-Known Member
With mine I found the collar sat in a slightly diferent part on the shaft so no problem
vyv_cox
Well-Known Member
Not quite sure that we are talking about the same thing. Mine is just a fancy bit of rubber tubing that fills the annular space between the stern tube and the bellows end. It and the bellows are retained by a hose clip. The stern tube on my Sadler only protrudes a short distance and has never had more than one hose clip, either with the old packed gland or with the PSS. Persisting with trying to fit two clips where there is only space for one will lead to shearing of the rubber.
charles_reed
Well-Known Member
Mine is exactly the same - a sort of rubber spacer to bring the stern-tube diameter up to the bellows internal id. Fits snugly, has never in 18 years and 4900 hours running, leaked.
The PSS seal is so uncomplicated and low-tech that I'm surprised anyone has problems with it - I have had to machine the rotor faces - but that was my own incompetence in using a hammer.
I've still got the original, unmarked nitrile bellows (to use as a spare), but carbon block is original with two changes of O-rings and set-screws.
The latter are difficult to get on this side of the Atlantic, being from memory 5/32") but an e-mail to the US saw 12 on their way back by airmail @ no charge.
Hence my total disbelief @ reports of poor customer service from PYI (who are the marine distributors). One of the most common problems seems to be people trying to fit a 1" seal to a 25mm shaft (or vice versa).
doug748
Well-Known Member
From memory there are two O rings on the rotor so you might well be ok - it is a static fit of course. With a very poor shaft it is possible that the rotor could wobble
If I had any doubt I would replace the shaft, they are not silly money if you choose your machine shop carefully.
charles_reed
Well-Known Member
The rotor is fixed closer to the engine than on a packed gland, so the wear point is likely to be different to the rotor.
I've had my shaft our and remachined on a couple of occasions (mainly to remove the clamp-marks at the end). My experience of getting a new 1238mm x 25mm shaft in 316 SS in Seville was that it cost me €105. One needs to be able to specify the taper angle correctly, there are more than one.
oldbilbo
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I can attest that both ASAP and Aquafax - perhaps others - currently stock and sell servicing kits including appropriate set-screws.
charles_reed
Well-Known Member
Excellent to know - but my PSS is 18 years old and I was in Greece when I needed the bits - 7 years ago. I knew we Brits would climb on the roundabout one day.
In fact mine is so old that it has no little tube into the carbon block so, like the Volvo seal needs burping, when first launched and when it starts to squeal because of overheating - as I now seldom run the shaft @ more than 1000rpm the latter is very seldom.
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