MD1/Jabsco Low water throughput

[seaesta]

I have replaced the impeller on my Volvo MD1 water pump which is made by Jabsco. The water throughput seems to take a long time to get going and be less volume than before. I have checked the output when hand cranking the engine by disconnecting the water inlet flexible pipe and watching the water output - which seemed to be OK. I wondered if there is some sort of thermostat or blockage in the head but when I blew through the system by mouth the flow seemed to be quite easy. The pump itself seems to be well worn (37 years of debris laden water). Any advice on
- how to test
- how much for a new pump and who can supply
- how hard are they to fit in situ (not bad access through a hatch).
Martin

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[Gezzer]

I had a similar problem on a Jabsco Fitted to my ageing Petter, Mostly a lack of flow except when the enging was running pretty much flat out, at tickover it did'nt bother, I changed every fitting from the intake to the injection point, new hoses, flushed the head etc, but nothing made much impression
A new impellor helped out for about an hour and then it was back to normal.

I eventually got in touch with the guys at Cleghorn Waring (www.cleghorn.co.uk)

They advised me that my pump was about 30yrs old and as a result the housing would be worn, and providing too much clearance for the impellor.
the pump was obsolete, but they had a newer design that with a 5 min mod was made to work, I think the pump was about £70.00, and they were very helpful, and fitting was easy.

The result excellent water flow at any speed, I also fitted a Vetus water strainer close to the water line, in place of the gauze one fitted to the inlet, this also increased the flow, probably due to the smaller head the pump has to draw.

Hope it helps.

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[kireonriley]

you could try putting a packer behind the cam which is situated inbetween the inlet and outlet ports try gascket paper ,when the cam wears it dous not bend the impellor viegns enough to work

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[seaesta]

Thanks Gezzer I have emailed Cleghorns and will let you know what they say
Martin

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[seaesta]

Hey it worked

Fitted a new Jabsco pump from Cleghorn Waring and the water throughput is now great. The sales bloke from Cleghorns was very helpful and sent the right fittings. The new pump had a slightly different alignment of inlet and outlet ports but I got round this with a bit of plumbing. Good fast ex stock service but not cheap at £138 plus VAT.

These pumps wear out and readers are urged to replace them rather than starving the engine of cooling water!

Martin

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