Manual Diaphragm Bilge Pump

[Sandgrounder]

I have a Henderson manual diaphragm bilge pump on my 20ft daysailer.
Recently it has started working less effectively and continuously sounds like it used to do only when the bilge was nearly dry.
I have removed and dismantled the pump and can see no obvious defects in the diaphragm or in the surfaces to which it seals.
Can anyone suggest what I need to do? Or do I simply buy a replacement diaphragm?

Simon

 

[pvb]

......can see no obvious defects in the diaphragm or in the surfaces to which it seals.

It's more likely to be the flap valves, or the surfaces on to which they seal.

 

[The engineer]

As suggested, it will be the valves. You can get a kit that replaces all the rubber parts, this is the best way ahead for pump that has not been serviced for a few years. If it has had the parts replaced recently it could be something stuck under a valve causing it to not seat.

 

[Sandgrounder]

Thanks you both; I shall have a look and will also try to get a service kit.
The sites all refer to a Mk5 pump but I'm not sure whetherb this is one.

Simon

 

[Sandgrounder]

Bilge Pumps - More advice needed

I have checked the valves as suggested and the outlet valve is in a poor state so I assume that this will be the cause of the problem.
However when I googeld for repair kits the only Henderson pump mentioned is a Mk5 which appears to have an octagonal diaphragm.
The Diaphragm on mine is 16cms diameter and is round. When installed the slot for the handle is covered with a white plastic fold down cover labelled Henderson. The body of the pump is labelled Munster Simms Engineering Ltd - UK. I have tried Google and drawn a blank on this. Can anyone identify this pump for me?

 

[pvb]

Could be a Compac 50 - check the photo and exploded drawing here on the Whale website. You can also see the correct part numbers there for spares.

 

[prv]

Munster Simms are the company behind Whale pumps, and I think also the Henderson name.

Pete

 

[VicS]

Or one of the Whale Gusher Urchins http://www.whalepumps.com/marine/product_list/7/

Or http://www.force4.co.uk/6755/Whale-Spares-Chimp-Mk2-Spares-kit---Nitrile.html I am sure Chimp was originally Henderson .. I think thats what I have!

 

[Sandgrounder]

Pete,

Thanks for all your help; the problem is solved and the spares kit is on the way. Clearly I need to work harder on finding my way around the websites because |i had looked at Whale but hadn't seen the compac 50

Simon

 

[pvb]

Lakesailored!!!!

 

[Sandgrounder]

Lakesailored!!!!

My apologies - reading the responses too quickly. I owe you many thanks for the effort you took to help me

 

[maxi]

Some of the Whale range are aluminium bodied, and after contact with salt water there is corrosion of the internal faces - particularly that flat faces upon which the flap valves close. This causes a gradual deterioration of performance leading to a total failure to work.

If this is the case, it is necessary to thoroughly remove all the corrosion and to re-face the lands under the flap valves with epoxy. this does provide a satifactory and inexpensive solution. The main lesson is probably to buy a plastic bilge pump although this is a counter-intuitive action.

 

[pvb]

The main lesson is probably to buy a plastic bilge pump although this is a counter-intuitive action.

The OP has a plastic pump, it's a Compac 50.