Advice please! Jabsco empties but won't fill...

G

gmatkin

Active Member
Joined
16 Nov 2005
Messages
55
Location
Tunbridge Wells, Kent
Visit site
We've got a 'blue label' Jabsco with a problem that's not listed in the troubleshooting points in manual.

With the cocks set to 'open', the no apparent leaks or kinks, the anti-siphon valves closed, it empties but won't fill...

I've had it to bits and replaced many of the seals (and the spring) using a service pack - the manual said I should replace them as they seem to be required and I did so, but without succ(k)ess.

Now, regular Jabsco users, is it likely that there is one remaining seal that would have this effect please? If not, I guess I have to presume that the intake is blocked... In which case is there a handy wheeze I can try without diving, such as using priming the tubing and forcing it back through the intake with, say, an airbed pump.

Many thanks,

Gavin
 
I have used the foot pump from my Avon inflatable connected to the inlet pipe to check that the pipe is clear and the inlet valve open. The crew stands on deck to check there are plenty of air bubbles coming from under the boat.
 
I seem to remember that having an antisyphon valve in the inlet can induce problems. Have you tried bypassing the antisyphon valve? Maybe remove it and tape the pipe ends together for a trial.
 
I had trouble re-priming the inlet pump on my Jabsco afterstripping and cleaning the valves. It just couldn't suck the water up over the anti-syphon loop (so I guess it works!). I unhooked the loop from the bulkhead and pushed it down so it lay along the cabin sole and then pumped it full. No problem since.

I've also been told that removing the hose between the pump and bowl and putting one's hand over it to act as a one-way valve can help by preventing the water dropping back between pumps - but beware you will get soaked when it comes through!

Rob.
 
The anti syphon loop and valve must be located between the pump and the bowl, replacing the short length of hose normally supplied connecting the two.
( See the instruction manual)

If it is located between the inlet seacock and the pump air will be sucked in resulting in little or no water being pumped in to flush.


The OP should check/replace the flap valve operated by the flush control lever if not one of the items already replaced.

I do not know what is meant in the original post by "the anti-siphon valves closed" ..... manual antisyphon valves ??
 
I shall give you my standard reply to all Jabsco problems.

Buy a complete new pump unit. They are not expensive.
Replace the whole thing.
If you still have the problem you know it is nothing to do with the Jabsco, so it is either seacock or piping.
Refurbish the old one at your leisure and then you have a spare.
 
gmatkin said:
We've got a 'blue label' Jabsco with a problem that's not listed in the troubleshooting points in manual.

With the cocks set to 'open', the no apparent leaks or kinks, the anti-siphon valves closed, it empties but won't fill...

I've had it to bits and replaced many of the seals (and the spring) using a service pack - the manual said I should replace them as they seem to be required and I did so, but without succ(k)ess.
Click to expand...

Was it working fine for months/years, then failed........ or has it just been fitted and never worked properly.

If the former, it's hard to see it being an anti siphon issue, unless the valve has been stuck closed since new, and has recently freed itself. Having said that, it's worth checking it's in the right place.
 
Ex-SolentBoy said:
I shall give you my standard reply to all Jabsco problems.

Buy a complete new pump unit. They are not expensive.
Replace the whole thing.
If you still have the problem you know it is nothing to do with the Jabsco, so it is either seacock or piping.
Refurbish the old one at your leisure and then you have a spare.
Click to expand...

+1

I had 2 Jabscos on Rogue, and had all kinds of trouble once they started to need servicing. Replaced both with new at £50 or so each - problems solved.......

Apart from having to replace both discharge pipes due to a build up over the 12 years since new :(
 
Thanks folks...

The installation is in a boat that's new to me - so I don't know whether it has ever worked properly in the past, but I'm sure it's odds-on that it has done. The installation has a professional look about it.

I very much like the idea of lowering the ingoing antisiphoning loop in order to fill it, as it's a lovely, simple thing to do. I may have a go with an air pump also.

Anti-syphon valves - I mean two small valves each at the top of the vented loops in the diagram to be found here:

http://www.jamestowndistributors.co...+Instructions+for+Jabsco+Manual+Marine+Toilet

Having bought a servicing kit I'm trying to avoid having to buy a new pump as well, though I realise it's a possibility.

The seal I haven't changed as it's fiddly to do and seemed ok is the one around the handle shaft. I guess Murphy's Law may come into play here...
 
The first thing to check is that you have not got the lever set to 'bowl empty', which lifts one or both of the valves on the seawater inlet part of the pump, allowing the water and air above the piston to move harmlessly in and out without ever going to the bowl. Assuming that the lever is correct, you are looking for something in the valve area that is having exactly the same effect. It is easy to locate the valves incorrectly so that they do not drop down as they should.
 
The inlet pump has two valves located at top of the pump. The lever to pump the bowl dry props one of these vales open to stop the pump from working. Toilets are usually left with the lever in the "dry" position which can cause the valve flap to become distorted, especially after being left unused for a long time. If you have not replaced this valve yet then it is well worth trying.
 
Have just been through this same problem. Replaced the whole pump with a new one as suggested earlier. The actual problem was the weighted flap valve at the base of the pump jammed open with deposits. Would not mess about with service kits except to rebuild the old pump for a spare - the new type seems superior in action and not expensive (as boat things go).
 
The answer is simple

Just undo the clip and pull off the hose from the back top of the loo, behind the seat. Lift it up as high as possible and fill it with water from a container. Then with the pump set to inlet, i.e. lever to the left, start pumping. You will get some spray of water and air as it primes but then 100% water. Take the pipe back and slip it on and do up the jubillee clip. Job done. My pump is in its 10th season. We have done 10,000+ miles and only changed one or two of the valves when water was backing into the bowl. They are excellent reliable units. A bit of vaseline smeared on the inside of the cylinder makes pumping easier.
 
Another thing to try is to put some grease on the piston that is located on the rod/handle I has similar problem it wasnt making a complete seal. Once the thing was primed it was fine
Maurice
 
Funnily enuf I had exactly the same problem last weekend. When I called in at the local toyshop I realised I didn't want to pay 55 euros for a replacement seal kit, so I took the old one to pieces and cleaned it (it didn't look dirty anyway) with washing up liquid, put it all back together again and it worked fine. Seems like the bit where you flip the lever over to give a dry flush was sticking in the closed position.

Of course it might only last until next weekend..................sigh.....................
 
TonyS said:
Just undo the clip and pull off the hose from the back top of the loo, behind the seat. Lift it up as high as possible and fill it with water from a container. Then with the pump set to inlet, i.e. lever to the left, start pumping. You will get some spray of water and air as it primes but then 100% water. Take the pipe back and slip it on and do up the jubillee clip. Job done. My pump is in its 10th season. We have done 10,000+ miles and only changed one or two of the valves when water was backing into the bowl. They are excellent reliable units. A bit of vaseline smeared on the inside of the cylinder makes pumping easier.
Click to expand...

Easier way fill the bowl from a bucket until it is right up to the rim that will prime it when you pump
 
You must log in or register to reply here.

Share this page

Top