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Jabsco 5870 water pump


36national

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thanks for your replies, am considering an electric pump but was advised against it and didn't have the presence of mind to ask why at the time. (Any ideas?) Sorry but the only part  available on that link is the impeller. My problem is that I can't get the pump to seal properly. Mating surfaces are scratched, gasket is Bran Flakes packet (Ive never even seen an original so have no idea how thick it should be), face plate is dished and the bolts are knackered. its on the engine and working but leaks slightly. Long term it needs sorting properly. 

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1 hour ago, 36national said:

thanks for your replies, am considering an electric pump but was advised against it and didn't have the presence of mind to ask why at the time. (Any ideas?) Sorry but the only part  available on that link is the impeller. My problem is that I can't get the pump to seal properly. Mating surfaces are scratched, gasket is Bran Flakes packet (Ive never even seen an original so have no idea how thick it should be), face plate is dished and the bolts are knackered. its on the engine and working but leaks slightly. Long term it needs sorting properly. 

 

The gaskets are very thin. If you make one too thick, the impeller won't seal on the front plate, so it either won't pump or have a very much reduced output. If I did not have any thin gasket paper, I would try the white plastic cereals often have inside the box.

 

I expect you know that you can reverse the ear plate in the bottom of the pump body and also reverse the front cover to allow for wear.

 

I expect it has frozen a some time. I would consider finding a metal or wooden ring large enough for the screw holes to fit and then carefully apply a plastic/hide mallet to try to take the dish out.  I think the plate screws are probably common across all those pumps so new ones should not be a problem.

 

If you put a sheet of fine emery paper on a sheet of glass you can go some way to true the plate face by rubbing it in circles and keeping on twisting it to even t the removal of metal. A surface plate is better than glass, but who has those to hand.

 

 

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9 hours ago, Tony Brooks said:

 

re gaskets, that thin really !! I would guess that cereal packet plastic is 0.1 mm.  I tried 0.3 mm gasket paper and thought it might be too thin with the impeller holding the face plate proud, the cereal packet is about 0.5 mm.

 

The bolts are slot head 3 BA I think and I can get em but one of the originals is missing and an M4 has been used instead. Theres probably enough brass to tap em out to M5 and use hex heads.

 

Is there anyone who can refurbish the pump properly ? I dont want to bodge it as its not my bote.

 

9 hours ago, Tony Brooks said:

 

 

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Is the leak from the face plate or from the telltale hole in the body between pumping chamber and mounting flange? If the latter it's the front seal that is leaking, so the shaft may be grooved or the bearings worn allowing the shaft to wave about.

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3 minutes ago, 36national said:

thankfully its from the face plate, what is the ear plate?

 

I just noticed that, but too late to edit it. Wear plate. Its the plate that sits in the base of the pumping chamber and is normally secured by the cam. I doubt it would come out with the pump on the engine. Normally I take the cam out (one screw) and the bang the pump down onto a piece of wood so the surface the face plate mates on is not damaged. I always put a smear of sealer on the back of the cam before replacing it so no air/water can leak under it.

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1 hour ago, 36national said:

now thats a damn shame. I already got a throat plate, if I had an ear plate too then I'd only need the nose plate to complete the set.

And a wicket keeper's box!

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Jabsco pumps, don’t you love them? 🤔 I had a Jabsco on a Beta engine that was leaking seawater from the body drain. When I stripped it down to renew the seal I found that it had been installed with the open side (with spring) facing the pump chamber. The spring had rusted away weakening the seal. I’ve installed the new seal the other way around and the leak has been solved for now. Pumping the raw cooling water means there is not much back-pressure on this pump delivery.

 

Also, the cover on this pump has been replaced with one of those quick-change types and has a tiny ‘O’ ring in a machined groove to provide the cover seal.

 

Bill

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1 minute ago, Redwing228 said:

Jabsco pumps, don’t you love them? 🤔 I had a Jabsco on a Beta engine that was leaking seawater from the body drain. When I stripped it down to renew the seal I found that it had been installed with the open side (with spring) facing the pump chamber. The spring had rusted away weakening the seal. I’ve installed the new seal the other way around and the leak has been solved for now. Pumping the raw cooling water means there is not much back-pressure on this pump delivery.

 

Also, the cover on this pump has been replaced with one of those quick-change types and has a tiny ‘O’ ring in a machined groove to provide the cover seal.

 

Bill

 

Er - lip seals should have the open face towards the liquid they are intended to seal. The problem with yours is that the garter spring was made of the wrong material. When/if pump pressure reaches the seal when correctly installed, it increases the pressure of the lip on the shaft. Doing it your way, the pressure will do nothing but try to lift the lip away from the shaft.

 

The not much pressure is also debatable if you have a wet exhaust. The pump outlet will be subject to exhaust pressure that can, with a partially blocked exhaust, stop pumping by forcing the impeller wings away from the body.

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10 minutes ago, Tony Brooks said:

 

Er - lip seals should have the open face towards the liquid they are intended to seal. The problem with yours is that the garter spring was made of the wrong material. When/if pump pressure reaches the seal when correctly installed, it increases the pressure of the lip on the shaft. Doing it your way, the pressure will do nothing but try to lift the lip away from the shaft.

 

The not much pressure is also debatable if you have a wet exhaust. The pump outlet will be subject to exhaust pressure that can, with a partially blocked exhaust, stop pumping by forcing the impeller wings away from the body.

Yes, thanks. It is more of an experiment, the way I’ve tried it. The original seal had a ferrous spring and I must admit to not buying spares from the pump’s supplier, but from an industrial bearing retailer so do not know if a seal with stainless or other non-ferrous spring was available.

 

Bill

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20 minutes ago, Redwing228 said:

Yes, thanks. It is more of an experiment, the way I’ve tried it. The original seal had a ferrous spring and I must admit to not buying spares from the pump’s supplier, but from an industrial bearing retailer so do not know if a seal with stainless or other non-ferrous spring was available.

 

Bill

 

If it works for you, then fine, but I am more concerned with what others may take from your post. I find the lip seals have a nasty habit of eventually wearing a groove in the shaft. Then you tend to get a short seal life.

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Conclusion. The Jabsco 5870 was rendered obsolete in 1978. It seems that Kingfisher bought up the old stock in the early 90's altered the mounting plate to fit the kingfisher base engine and renumbered it the Jabsco 5870 KD. In short even if I find one its unlikely  to fit without a degree of McGyvering.  The face plate needs remaking from scratch, the body skimming as Tony suggested,  the pump  body  tapping,  none of which is the end of the world but it still leaves  you  with  a pump which is  a   right    $"%&%£-nard    to get at and which will set you back £44.00 plus VAT when you need to buy one of the 2 impellers currently available in this country.  The owner has decided to replace with a 12 volt electric pump as soon as its convenient, (got to admit it sounds like the common sense decision.) 

 

Questions:

 

Does matching flow rates matter that much? Its a skin tank system with a total volume of about 30 litres. 

Does it matter where the power comes from? Straight of the alternator seems simplest or maybe from the ignition.

Are there any disadvantages to using an electric pump as opposed to a mechanical one? From an engineering point of view, not the purist in me going,"yeah but its just like err  wrong innit."

Anyone need spares for a Jabsco 5870 KD?

 

Thanks for your help and especially Jabsco technical support who were spot on," I've worked here for fifteen year and its the first time I've been asked about one of those."

 

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Assuming the Jabsco is the pump pushing water through the skin tank.

 

Anything connected to the batteries will be fed from the alternator when it is charging, so it won't matter where you connect the pump. The alternator output terminal is normally live all the time, so that won't work. I would go with the aux position on the ignition switch and maybe use a relay if the pump power suggests it a good idea.

 

The volume of water circulating needs to be able to carry the full amount of heat the engine produces away, so for safety I would ensure the electric pump can produce the same output as the Jabsco.

 

 

 

 

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I've seen that diagram and it don't bear much resemblance to the pump I've got. However, at least the inlet and outlet are in the positions shown with a grease cup at the top. Then again that don't matter as the pump isn't mounted upright on the engine, which in turn doesn't matter because the engine isn't mounted upright either. 

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