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

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FairweatherDave

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First time going in where angels fear to tread. Not the nicest job but having taken the pump home and being out in the garden I went in.....
Found two suprises. The previous owner seems to have used a bright orange silicon sealant. Should there be any sealant? I'm guessing it was a bodge leak repair? Or is it an extra as well as buying the service kit? Secondly under the crud/limescale there was a large amount of what seems like a hard candle wax. A lot of it. I am theorizing it might be olive oil sediment that has taken on toilet cleaner dye colour, or else it is simply a toilet freshner product that accidentally got flushed. But it definitely seemed like a hard wax. Mystery. Observations welcome. Anyhow the plan is to buy a service kit (about £24 from ASAP) as from what I have read Lavac Zenith's are good (if old and discontinued). I can see that the toilet seat hinge might be the problem area in the future though. And I know you can get Jabasco's for about £100.
 
The orange stuff sounds like "Instant Gasket" Should not be necessary...

Dunno what the wax is ... are you sure its not a calcite deposit. Thats what you might expect to find. What about the pipes . Are they Ok or blocked with the same stuff

Repair while/if you can still get the spares then, as sailorman, says replace with a Lavac popular
 
VicS said:
The orange stuff sounds like "Instant Gasket" Should not be necessary...

Dunno what the wax is ... are you sure its not a calcite deposit. Thats what you might expect to find. What about the pipes . Are they Ok or blocked with the same stuff

Repair while/if you can still get the spares then, as sailorman, says replace with a Lavac popular
Click to expand...

The Zenith lid is very very expensive even eye watering. just not economical
 
The seal around the outlet joker valve can be very difficult to make, due to rather poor design. It's pretty common to use a smear of sealant around the screws and where the valve body seats against the pump body. I can't help with the waxy deposits, the olive oil hypothesis sounds plausible although it's entirely unnecessary to put oils down a Lavac.
 
KenMcCulloch said:
The seal around the outlet joker valve can be very difficult to make, due to rather poor design. It's pretty common to use a smear of sealant around the screws and where the valve body seats against the pump body. I can't help with the waxy deposits, the olive oil hypothesis sounds plausible although it's entirely unnecessary to put oils down a Lavac.
Click to expand...
I think the turquoise wax might have been a candle. But it was under the crud as if it had been put there to smooth the internal shape of the chamber, (it has little ridges.) The wax is definitely not a limescale type deposit. The orange sealant was obviously put there on purpose.
I will double check the condition of the hinge. It seemed all fine to me but maybe needed a bit of tightening up. I know the seat price is nuts coz it is a discontinued one.
What I do like is the system seems quite a simple one to service. Presumably why some are recommending the Popular model rather than a cheap Jabasco?

On the joker valve it seems to take the correct shape to seal, ie no obstructions but the bottom half feels very stiff and old. Not sure if it needs replacing but having got this far I think a fresh one is in order. Diaphram looks fine though as does the inlet valve
 
VicS said:
The orange stuff sounds like "Instant Gasket" Should not be necessary...

Dunno what the wax is ... are you sure its not a calcite deposit. Thats what you might expect to find. What about the pipes . Are they Ok or blocked with the same stuff

Repair while/if you can still get the spares then, as sailorman, says replace with a Lavac popular
Click to expand...
Don't know about the pipes. They are still on the boat:). But I will be checking that hole at the top of the loop as I have the symptom of the pan overfilling after flush
 
KenMcCulloch said:
The seal around the outlet joker valve can be very difficult to make, due to rather poor design. It's pretty common to use a smear of sealant around the screws and where the valve body seats against the pump body. I can't help with the waxy deposits, the olive oil hypothesis sounds plausible although it's entirely unnecessary to put oils down a Lavac.
Click to expand...

yep! me too. took it all to bits and cleaned pipes/pump etc after a few yrs use from new-for peace of mind as much as anything--replaced and had odd drip!!!! took apart and used silicone as recommended somewhere -no further problems -as yet!!!!
 
FairweatherDave said:
Don't know about the pipes. They are still on the boat:). But I will be checking that hole at the top of the loop as I have the symptom of the pan overfilling after flush
Click to expand...

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.
 
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.
Click to expand...

She's reading this :)!
 
the outlet valve is badly designed as a previous post says. there are four metal washers 'lost' in the rubber body for the four self tapping screws to attach it to the pump casing. problem is that even minimal overtightening strips the metal washer and the screw simply revolves without taking up the valve leading to a poor seal and leaks. i damaged the first outlet valve and only by sweet talking the manufacturers was I able to get a replacement without buyng a whole new kit again. when i got the new one i used a fair amount of silkaflex as an adhesive and sealant to seat the valve as well as trying to tighten the screws without stripping the washer. the result has been successful but i would never ever again replace the outlet valve without silkaflex. maybe a manufacturer trained technician could do it but for the likes of me and you it's just not feasible.
 
Well loads of food for thought now. Thanks all. Any recommendations for the type of silicone sealant, (other than sikaflex) or anyone one know what the orange one is?
 
FairweatherDave said:
Well loads of food for thought now. Thanks all. Any recommendations for the type of silicone sealant, (other than sikaflex) or anyone one know what the orange one is?
Click to expand...

Orange one, as I said earlier, is probably Hermetite "Instant Gasket" http://www.parkandholmes.co.uk/products/462/hermetite-instant-gasket.htm


I'd think almost anything you have handy will do. Builder's silicone even although the sanitary grade would be a nice choice but if you have cartridge of Sikaflex open use that.
 
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Burnham Bob said:
but i would never ever again replace the outlet valve without silkaflex. maybe a manufacturer trained technician could do it but for the likes of me and you it's just not feasible.
Click to expand...
I've removed, cleaned and reassembled the pump every winter for the last 10 or more years. I give all the rubber parts a light coat of silicone grease and I've not, as yet, ever needed any sealant. I've also not yet needed to replace any parts. The simplicity of the setup is the primary reason I installed it.
 
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