Raw water pump - Perkins 4-108
 

Hi all,
In Georgetown, Great Exuma.
Noticed today that their is a leak from the raw water pump from the
seal between the pump and the engine block. My understanding is that
this means the pump needs rebuilding/replacement.

Again - the drip is not from the faceplate, or other - from the place
where the pump body attaches to the engine block.

What is my best course of action? - I do have a spare raw water pump.

Please advise on the best point by point troubleshooting sequence.

Thanks to all who advise,

Mike.

Raw water pump - Perkins 4-108
 

"beaufortnc" wrote in
ups.com:

Again - the drip is not from the faceplate, or other - from the place
where the pump body attaches to the engine block.



Pull off the faceplate and remove the impeller. Look back there from the
inside and see if it's cracked. Wiggle the shaft around to see if the
bearing is loose (worn out). If it's just drippin', and pumping fine, so
what?.....

Everyone in a sailboat needs to ride in the engine room of your favorite
shrimp trawler....for a little "reality check"....(c; Wear old clothes.
You might get sprayed with "something"...hee hee.

Our Perkins is always dripping "something" from "somewhere". Maybe it
had something to do with getting pumped full of seawater when the idiots
at the shipyard replaced the illegal, but great-working, grease-packed
packing gland with the dripless and hooked up the water injection line to
the Perkins without anyone thinking of a ANTISIPHON LOOP! Flooded the
hell out of the poor thing. The crankcase looked like the Exxon Valdez'
tarballs!

We pumped her out, replaced one of the injector mounts the big starter
dislodged, another injector that wasn't impressed, blew her out and
changed the oil a "few times" until what drained out looked like oil, not
seawater. Cranked her up and ran it all night to boil out the rest.
She's fine....like a fine watch. Great engine if it'll take that
abuse....

And, if you give up boats, you can pull the Perkins out and put it back
in the tractor it came from...(c;

Raw water pump - Perkins 4-108
 

"Larry" wrote in message
...
"beaufortnc" wrote in
ups.com:

Again - the drip is not from the faceplate, or other - from the place
where the pump body attaches to the engine block.



Pull off the faceplate and remove the impeller. Look back there from the
inside and see if it's cracked. Wiggle the shaft around to see if the
bearing is loose (worn out). If it's just drippin', and pumping fine, so
what?.....

snip

Allowing the pump to drip seawater is a very bad idea. The salt water can do
damage to the motor mounts, etc. I had to change a motor mount shortly after
purchasing my old 27 footer because the PO allowed the raw water pump to
drip constantly on it. Even though the pump had been fixed by the time I
bought the boat the damage had already been done. Likewise, on my 30 footer
the pump was leaking when I bought the boat and there is visible corrosion
from however long the PO ignored the leak. (I replaced the pump first thing
and the motor mount does not appear to be too far gone.)

As for the pump, you might want to contact Depco Pump (www.depco-pump.com).
They are a great resource for all pump-related issues. They can either
rebuild it or give you a good idea how you might do it, and more than likely
supply any parts you may need. Since you have a spare perhaps you could just
slap that one on and send them the leaking one to fix rather than messing
with it. Either way, they are a good source.

--Alan Gomes

Raw water pump - Perkins 4-108
 

I'm trying really hard to picture this, but not succeeding.

On my engine, the raw water pump is pulley driven, mounted on a
bracket. You have to take that sucker off to change the impeller, a
situation I'm trying desperately to figure out how to change via a
direct-drive pump, but can't yet figure out how to tell my engine SN
(which isn't apparent where the manual sez it should be) which
apparently is needed to confirm that a direct drive pump is available.
But, I digress...

My freshwater pump is mounted to the engine, and has a gasket such as I
infer from your post. However, the typical freshwater pump failure is
from the bushing, producing a leak forward, not at the engine body.

However, my Perkins is a 4-154. My understanding had been that these
were the same block - BICBW, of course, as happens more and more the
older I get. Is there an impeller you've changed in the raw water
pump? And if so, this pump is mounted with a gasket/seal between it
and the engine? Or are we talking about a different pump?

L8R

Skip, very sore from my marine yard sales adventures yesterday


Morgan 461 #2
SV Flying Pig KI4MPC
http://tinyurl.com/384p2 The vessel as Tehamana, as we bought her

"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails.
Explore.
Dream. Discover." - Mark Twain

How long will you be in Georgetown? I will be heading that way in a few weeks. perhaps I can bring you a pump or rebuild kit?

Email me at

Raw water pump - Perkins 4-108
 

On 18 Mar 2006 19:10:52 -0800, "beaufortnc"
wrote:

Hi all,
In Georgetown, Great Exuma.
Noticed today that their is a leak from the raw water pump from the
seal between the pump and the engine block. My understanding is that
this means the pump needs rebuilding/replacement.

Again - the drip is not from the faceplate, or other - from the place
where the pump body attaches to the engine block.

What is my best course of action? - I do have a spare raw water pump.

Please advise on the best point by point troubleshooting sequence.

Thanks to all who advise,


You could either try to carefully remove it and cut a replacement
gasket or run a bead of engine gasketing material along the mating
surfaces if you think it will suffice. The rebuilding can wait, or
just swap in the new pump entirely and use a gasket or a bead of
sealant.

There's leaks and then there's leaks. If the pump is delivering well,
I would simply regasket and if drips happen, pump out the bilge. If
it's sending a steady stream onto the engine or if the output is
weakened, that's a different case.

R.

Raw water pump - Perkins 4-108
 

Is this pump leaking sea water from the little hole between the pump and the
engine? If it is then you need to get it fixed before the baring fails.
Defender has the best prices for "major" rebuild kits. I have used Depco
(impellor, seal, gasket = $90) rather than rebuild my own but I understand
it is not that difficult. Depco pulls the seal and inspects the baring.
If this pump is leaking oil then it is a matter of your personal tollerance.
Now if the 4-108 rear seal was this easy I could stop buying diapers.
-Allen

Raw water pump - Perkins 4-108
 

Raw water pump - Perkins 4-108
 

wrote in message
.. .
I recently replace the impeller in the sea water pump of the
4-108 on a
boat I bought recently. Should there be a gasket to replace as
well?
This pump has the speed seal quick remove cover. Looking through
catalogs and shelves of boat stores I don't see gaskets for it.
The
impeller came in a small box of its own with no gasket for the
housing.

If that leaves you with a metal cover pushing against a metal
body, it'll leak, and without a gasket, may jam the impeller.

When you took the cover off, was there a thin paper gasket in
place? Perhaps which came apart and just looked like gunge (which,
of course, being a tidy fellow, you scraped off) after you prised
the lid off?

It is also just possible that the Speed Seal design has been made
to work with a rubber ring gasket (I don't know them), but in that
case there would be a groove in the cover to locate the ring, and
the centre of the cover would be slightly proud compared to the
mating surface.

So a quick check of the cover will tell you what type of gasket to
get. With care, and knowing the appropriate thickness (I think
yours would be 0.3mm, but check with Jabsco), you can make your
own. Oil some paper, punch holes in place to mate with the bolts,
very gently tap the paper against the pump face edges with a small
hammer (preferably lead!), remove the paper and cut any edges that
the hammer didn't cut. and there's your gasket.

Or go and buy a whole lot in one go . . .
--
JimB
http://www.jimbaerselman.f2s.com/
for opinions comparing Greek cruising areas

Raw water pump - Perkins 4-108
 

It is also just possible that the Speed Seal design has been made
to work with a rubber ring gasket (I don't know them),

Boy I feel dense. Yes, the speed seal cover has an "O" ring in it.