Servicing Lavac manual pump (Henderson)..silicon and wax inside

VicS said:
If that hole is partly blocked the vacuum will be maintained for too long , so the pan will end up with too much water in it and it'll take ages before you can open the lid.
If it's totally blocked water could continue to syphon in until you shut the seacock or the boat sinks.
All it needs a a very occasional poke though with a bristle off SWMBO's toothbrush.
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Just back from an inspection of the pipework. There is no hole at the top of the loop. The pipe is not original so poor instalation. The hinges are fine on the seat, so fingers crossed we have a sorted Lavac. (Thanks for the offer Scotty, if I lived closer I would be interested, but hopefully you might get interest by this thread anyhow).
 
FairweatherDave said:
Just back from an inspection of the pipework. There is no hole at the top of the loop. The pipe is not original so poor instalation. The hinges are fine on the seat, so fingers crossed we have a sorted Lavac. (Thanks for the offer Scotty, if I lived closer I would be interested, but hopefully you might get interest by this thread anyhow).
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it could be collected for a tenner
interparcel
 
not sure if the service kits are the same as the original fittings you have in a ten year old pump alahol2. the new outlet valves are very flimsy in the way the screws bite into the 'lost inside' washers. congratulations on achieving something i found impossible!
 
Burnham Bob said:
not sure if the service kits are the same as the original fittings you have in a ten year old pump alahol2. the new outlet valves are very flimsy in the way the screws bite into the 'lost inside' washers. congratulations on achieving something i found impossible!
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Just wondering if you could drill out your self tapping holes and replace with nuts and bolts like the earlier version of the pump?
I'm only going to introduce silicon if my first attempt without fails to seal things. I have the earlier type of pump with no self-tappers.
 
FairweatherDave said:
Just wondering if you could drill out your self tapping holes and replace with nuts and bolts like the earlier version of the pump?
I'm only going to introduce silicon if my first attempt without fails to seal things. I have the earlier type of pump with no self-tappers.
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I Think some wires have become crossed. The earlier reference to nuts and bolts was to the fastenings which hold the two halves of the pump body together. The outlet valve is held in with self-tapping screws, the idea that there is some metal embedded in the rubber is new to me, never found any evidence of such a thing myself. I may well be overhauling a Henderson pump tomorrow so will pay particular attention to that.
 
KenMcCulloch said:
The outlet valve is held in with self-tapping screws, .
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Hi Ken. Just looked at my pump in the shed and the outlet valve is definitely held to the casing by nuts and bolts, 2 long and two shorter pairs. That may just be mine though, and I'm only learning about the pump, which could well be from 1979.
 
Bit more reading of this (if anyone still interested:))
http://www.blakes-lavac-taylors.co.uk/pdf/lavac.pdf
the original.
On page 26 it advises using silicon when changing the seals and around the nuts and bolts (to ensure a vacuum can be formed). I wonder if gunking everything with silicon makes it more likely you would simply replace the seals with a new set rather than have to clean up the old seals and get old silicon off. Did they get supplied new pumps with silicon used? I'm just debating whether to buy a service kit as the pump bits look fine (apart from the silicon everywhere). I do have a few months to experiment before perhaps the inevitable service kit purchase.
(To avoid confusion (of myself) the pdf refers to silicon sealant, whereas alahol2 gets away with silicon grease)
 
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FairweatherDave said:
Bit more reading of this (if anyone still interested:))
http://www.blakes-lavac-taylors.co.uk/pdf/lavac.pdf
the original.
Did they get supplied new pumps with silicon used? I'm just debating whether to buy a service kit as the pump bits look fine (apart from the silicon everywhere). I do have a few months to experiment before perhaps the inevitable service kit purchase.
(To avoid confusion (of myself) the pdf refers to silicon sealant, whereas alahol2 gets away with silicon grease)
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Definitely no silicone sealant in the originally supplied pump. The diaphragm is made of quite thick, softish rubber (neoprene?) and seems to create a perfectly good seal on its own. I could imagine that you may need a bit of sealant on the outlet valve screws if they have stripped the threads in the valve base. I think if the threads stripped on mine I would replace them with nuts and bolts and probably use a minute touch of sealant. Perhaps I was lucky not to have read the instructions?
For info my pump is held together with self tappers but they seem perfectly adequate.
 
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