TOILET BABY BLAKE MISERY

[steveg]

I have Baby Blake (UK4000 pounds) toilets on a classic yacht. I have continuous problem with pumps, but mainly the flush water supply pump.

We are about 2.25ft below water level, and flush with sea water into a vented black water tank. The sea water inlet cock is about 6 ft below water and comes via a filter. I have removed the water supply hose and the water flows freely, but the pump handle is extremely difficult to use.

I have cleaned out the supply pump and sanded the bore with 2000 grit paper, and replaced all rubber seals etc. At one stage earlier I put a light grease on the pump seal which worked well for a short period, but the grease has now been cleaned again with new seals.

We are talking about the most simple mechanical pump that has been used for the last 50 years. The problem must be in the pump itself, the link pipe to the pan, or it is creating a suction at the pump entry. This is sending me bonkers. Help!

[DeborahLee]

Is the flushing water supply line ventilated?

[boden36]

You should be able to take the water inlet hose off the pump and connect another short hose into a bucket. This will either confirm or rule out whether inlet restriction is your problem.
My bet would be the seal around the pump shaft is binding for some reason.
Maybe spray some silicon lube onto the shaft and if that makes a temporary improvement you will know where your trouble lies.

Regards,
Richard.

[steveg]

Thanks Deborah and Richard for input.
1. The water supply line is not vented. It comes direct from seacock to toilet and there is no vented loop above the waterline.
2. With the inlet hose off at the toilet, the water flows freely so I don't think it is that supply hose problem. Remember that we have 2 toilets with separate hose to each and they have the same problem. With a common problem on both it makes me wonder. When freshly installed after cleaning and new seals, both toilets work perfectly. The next day we are back to hard to pump.

I have just wondered about the link part between water pump and the pan. I will disconnect the hose between the water flush pump and the pan and see if there is a problem there.

[steveg]

I believe I may have found an aswer. The yacht toilets never worked properly; always stiff and jerky often with poor water quantity. A couple of weeks back we removed toilets fully with a plan in desperation to rebore the cylinder and put in a plastic cylinder liner but that wasn't possible, so we rebuilt again as was.

When we removed the toilets the water flowed from the supply pipe but I didn't take much count. I then spent dozens of hours figuring how to make the pump redundant by spring cock valves but retain the old pump for its looks. I could not find anything to handle salt water and spatial limitations. But these toilets have been working for 100 years so I went back to try and find the problem, and tried this forum.

After the replies, it then occurred to me that one common element in the system is the inlet flush salt water, which enters the hull about 1 mtr below water and flows directly to both toilets ....... and the water runs freely. The total system is below water level. Why do we need a pump when the free water runs faster than the pump? I was onto something, so I went to a diving web site and with their calculations established we had likely 15 - 20 psi at the pump inlet. The secret and the problem all along is that the supply inlet pressure is too great for the pump to work properly.

In researching the toilet owner's manual to try and see where a pressure-reducing valve could fit, I noticed a midget note that says if the toilet is well below water level, there is an optional extra heavy valve available for the inlet to the pump. I immediately ordered them from UK and await delivery. I am positive I have found the problem after 3 years, but what a chase!

Incidentally, Hurrica V I believe won her first race on 22 March, and turned 90 on March 24! What a present.