I have a Johnson F4B-9 cooling pump which is leaking water from the rear where the cam comes out. I do have a spares kit which includes five gaskets, (one of which I just found in my tea), a rubber O ring which looks as though it is the face plate seal, an impeller and what looks like a grub screw but it is quite long.
I'm a little bit trepidant about taking the bugger to pieces as I have just put my motor back in and don't want any hiccups to slow down the process.
Can anyone tell me if the leak is likely to be coming from the bearing?
Hi Japie
Not familiar at all with the internals of your pump but in mine on my 2gm Yanmar there is 2 bearings and a seal with the seal being closest to the impeller to prevent sea water coming out of the front of the pump behind the pulley
In the photo the bearings are numbers 16 and 17 and the seal is 18
If you have a water leak past the seal you would normally replace the bearings and the seal and have a good look at the surface on the shaft where the seal lip runs to make sure there is no grove worn in it
Regards Don
Its hard to see properly but Id say the seal number 18 would be worn and letting water leak.
Some pump housings have a hole behind the pump housing in your pump Id say just behind the bolt flanges on the other side from the pulley
if that make any sense
it would look like a normal oil seal probably
it stops water coming out from where the impeller runs
If you think of the old Holden water pump and just behind the pulley there's a hole in the pump housing so water can escape if the seal is leaking
www.oldmarineengine.com/discus/messages/3/139411.html
see the hole in this photo on the impelor side of the hole there will be a seal mostly likely a normal double lipped oil seal.
The Johnston run a stainless steel spring in the oil seal where as a genuine bukh oil seal runs a bronze spring ( bit a of useless info there
Japie)
That's why there a real sea motor you wont find that in a marinize small truck engine that Cisco runs
If it's the same bearing and seal as my pump you may need to replace the shaft or possibly the whole pump as you can see below the condition of my old shaft before I replaced all the internal parts costing just over $500.
Japie,
sounds like the seals are leaking and if you have to go that far you may as well overhaul the entire pump.
3 x bearings, and double lipseal, .... easy enough if you take your time and lay out parts as they come apart ....in order.
Here is the link to the parts list for your pump and the exploded drawing for it.
www.pumpvendor.com/media/johnson/Johnson_10-35240_series.pdf
I have never dealt with these guys but ..... say they send their parts worldwide.
Hoping it helps
Japie,
This link will take you to a much clearer drawing and easier to follow
www.depcopump.com/datasheets/johnson/10-35240-1.pdf
enjoy ...
Thanks DKD, Ramona, HG and Don
I did a whole heap of reading and video perusing last night and have reached the same conclusion, rebuild is in order. What a mission this has been. I have had the motor out, repaired the alternator mounting and cleaned her up and painted her but in the process I bust the temperature sender which shouldn't be too hard to source here and the fuel cut off solenoid is playing up. I'm going to attack that after I have my boiled eggs!
Thanks Sam.
I finally managed to get the engine started. Had a conniption when I found salt water in the inlet manifold until I realised it came from the bottom of the dinghy when transporting the engine from shore.
She's purring as I type. I've take the solenoid off and will not replace it. The throttle turns her off when pulled tight back.
And the raw water pump has stopped leaking! I will still get a rebuild kit though.
Before you spend a small fortune on OEM-branded stuff, be aware that you can reco it very cheaply. The only OEM bits you should need are the impeller and gasket.
The bearings and seals will be generic types, equivalent for which you can get from a bearing shop for peanuts. If the cover is scored, just clean up the other side and reverse it. The shaft will have marks from where the seal lip contacts it. Polish these out to a mirror finish with progressively fine emery.
I've done the (very similar) pump on my Yanmar 2GM this way and it is still leak-free 5 years down the track.
Cheers, Graeme
I have a VDO sender if its any use to you Japie part number 320.002 still in the packet can pack it with your burner that's three beers now
Still not sure who's going to drinkem
Except for the plastic hose. Reinforced rubber would be nice with double clips for the hoses below waterline.