Jabsco Macerator Pump

Thepipdoc

Thepipdoc

Well-Known Member
Joined
13 Jun 2009
Messages
937
Location
Torquay, Devon/River Dart
Visit site
For some time now I've had difficulty discharging black waste from my holding tank ( about 20 gallon capacity). It either doesn't discharge or when it does it takes "yonks"!
I've taken the pump apart and the impeller apears to be fine. However, never having replaced an impeller before I don't know a good one from a bad one.
The motor runs fine so I can rule this out.
I know Jabsco claim the pump doesn't need primming but is this always the case?
Any ideas what could be the problem?
Short of replaceing the pump I don't know what else I can do!!
Thanks
 
if the pump won't prime you may have an air leak from the tank to the pump inlet. if in doubt change the impellor as it may be "spun out" (slipping on the drive shaft. and check the condition of the pump body (bad scratches, rough surface etc). Also - you won't like this bit - make sure the hose from the pump to the tank is completely clear and the hose from pump out of the bottom of the boat. Take the pump out of the boat and test it with a 12v battery and hold the pump inlet so it is just in a bucket of water - it should pump loads of water really quickly.
 
Last edited:
kashurst said:
if the pump won't prime you may have an air leak from the tank to the pump inlet. if in doubt change the impellor as it may be "spun out" (slipping on the drive shaft. and check the condition of the pump body (bad scratches, rough surface etc). Also - you won't like this bit - make sure the hose from the pump to the tank is completely clear and the hose from pump out of the bottom of the boat. Take the pump out of the boat and test it with a 12v battery and hold the pump inlet so it is just in a bucket of water - it should pump loads of water really quickly.
Click to expand...

Thanks for this - I appreciate it.

I've taken both inlet and outlet pipes off the pump and when I put my hand over the inlet I can barely feel any suction and the same at the outlet.
I understand what you mean about the impeller being "spun out".
I can still see a flat section within the impeller - where the shaft from the motor goes. Is it still possible that it has spun out?
 
I'd put money on the impellor being at fault. I've had to change mine twice in one season, guess it must be a common failing. Not the best of jobs...................
 
Thepipdoc said:
I understand what you mean about the impeller being "spun out".
I can still see a flat section within the impeller - where the shaft from the motor goes. Is it still possible that it has spun out?
Click to expand...

When the impellor has "spun out", that exact shaft section is spinning freely, meaning the impeller doesn't actually turn over
 
Close the seacock.
disconnect the jabsco
use a wet rag and electrical tape to join your dinghy foot pump to the hull fitting pipe.

pump the footpump to pressure
keep pumping while you open the seacock

Now you know if the seacock is clear, if it was blocked you can unblock it by pumping hard.
close the seacock

now disconnect the jabsco from the tank pipe and repeat to make sure the tank outlet pipe is free.

With the jabsco connected again and seacock open it should work.

If it doesnt,

close the seacock.

use your dinghy foot pump to blow into your breather pipe, it should blow up and pressurise.

Now open your seacock and keep pumping with your jabsco running, the dinghy foot pump will help push any solids out .
the tank and pipes are all clear and free running now without you having to touch any c r@p.
 
Thanks for all the replies.

I tookk the pump off the boat last night and this morning I rigged a makeshift set up at my work place and lo and behold it worked!!
I have no idea why but it did.
I took it back to the boat tonight and I'm pleased to say it works!


Lots of excellent suggestions and I'll bare them in mind if/when it goes pear shaped again.
Thanks again.
 
I have a similar issue with my "grey" pump. I have an inkling that there is some crud at the inlet orifice, and will ahve a look at this in a few weeks when I get a bit of spare time.
 
You must log in or register to reply here.

Share this page

Top