Perkins 4.108 with Sherwood G-65 raw water pump

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1

Posted by michel.capel (michel.capel@…>)

I have a Perkins 4.108 with a Sherwood G-65 raw water pump. I just
rebuilt the pump because it was badly leaking. The seal was
compressed sideways because the bearings were done. Fortunately no
water had entered the engine along the drive shaft of the pump.

I ordered a rebuild kit in the US, couldn’t find one on stock here in
Europe.

It wasn’t easy to get the two ball bearings off the shaft without the
proper tools; I damaged the shaft end a bit and had to grind it in
shape again. Inside the pump is a half moon between inlet and outlet
called ‘cam’. What struck me as odd is the fact that the cam is
screwed to the inside of the body through a too large hole without
seal. On the pump drawing they suggest to seal it with epoxy or
locktite (they use the brand name Permatex). Not a real nice
engineering solution, I feel, but with instantly curing thick epoxy
it seems to work.

What I noticed for the first time, is that the pump is mounted upside
down against the Perkins block. The cam in the pump body is usually
on top, here it’s at the bottom of the pump. The cam screw is
therefore also on the bottom and cannot be used as a bleeder for the
pump. Yes you need to bleed this pump, which I’ve never heard before.
Perhaps that’s because the inlet and outlet are at the bottom of the
pump body too, therefore air gets trapped in the upper part of the
pump. The only way to bleed it is to loosen all four screws on the
front plate, start the engine (water gushing around all over the
engine room) and then tighten the screws, the top one last. Only
after doing this, I got water out of the exhaust.

2

Posted by Robert (robert@…>)


Michel,

You may also have to replace the cover
plate on the pump as this is also an item that wears and this can also give
priming problems. To guarantee pump priming, even on new engines the pumps
impellers are usually given a liberal coating of petroleum jelly (Vaseline) or
similar and normally a small sachet of this is included with replacement
impeller kits.

Best Regards
Robert Furborough

PO
Box 5, Arapahoe, NC 28510
www.betamarine.net
(877) 227-2473
(252) 249 2473





From:
FreedomOwnersGroup@yahoogroups.com [mailto:FreedomOwnersGroup@yahoogroups.com] On Behalf Of michel.capel
Sent: Thursday, August 21, 2008
3:05 PM
To:
FreedomOwnersGroup@yahoogroups.com
Subject: [FreedomOwnersGroup]
Perkins 4.108 with Sherwood G-65 raw water pump




I have a Perkins 4.108 with a Sherwood G-65 raw water
pump. I just
rebuilt the pump because it was badly leaking. The seal was
compressed sideways because the bearings were done. Fortunately no
water had entered the engine along the drive shaft of the pump.

I ordered a rebuild kit in the US,
couldn’t find one on stock here in
Europe.

It wasn’t easy to get the two ball bearings off the shaft without the
proper tools; I damaged the shaft end a bit and had to grind it in
shape again. Inside the pump is a half moon between inlet and outlet
called ‘cam’. What struck me as odd is the fact that the cam is
screwed to the inside of the body through a too large hole without
seal. On the pump drawing they suggest to seal it with epoxy or
locktite (they use the brand name Permatex). Not a real nice
engineering solution, I feel, but with instantly curing thick epoxy
it seems to work.

What I noticed for the first time, is that the pump is mounted upside
down against the Perkins block. The cam in the pump body is usually
on top, here it’s at the bottom of the pump. The cam screw is
therefore also on the bottom and cannot be used as a bleeder for the
pump. Yes you need to bleed this pump, which I’ve never heard before.
Perhaps that’s because the inlet and outlet are at the bottom of the
pump body too, therefore air gets trapped in the upper part of the
pump. The only way to bleed it is to loosen all four screws on the
front plate, start the engine (water gushing around all over the
engine room) and then tighten the screws, the top one last. Only
after doing this, I got water out of the exhaust.



Attachment: (image/jpeg) image002.jpg [not stored]

3

Posted by Robert (robert@…>)


Ooops, I replied to this message from my
work computer and forgot to delete the automatic signature. My sincere
apologies.

Regards
Robert





From:
FreedomOwnersGroup@yahoogroups.com [mailto:FreedomOwnersGroup@yahoogroups.com] On Behalf Of Robert
Sent: Thursday, August 21, 2008
3:13 PM
To:
FreedomOwnersGroup@yahoogroups.com
Subject: RE: [FreedomOwnersGroup]
Perkins 4.108 with Sherwood G-65 raw water pump





Michel,

You may also have to replace the cover plate on the pump as this is
also an item that wears and this can also give priming problems. To
guarantee pump priming, even on new engines the pumps impellers are usually
given a liberal coating of petroleum jelly (Vaseline) or similar and normally a
small sachet of this is included with replacement impeller kits.

Best Regards
Robert Furborough

PO Box 5, Arapahoe, NC 28510
www.betamarine.net
(877) 227-2473
(252) 249 2473





From: FreedomOwnersGroup@yahoogroups.com
[mailto:FreedomOwnersGroup@yahoogroups.com] On Behalf Of michel.capel
Sent: Thursday, August 21, 2008
3:05 PM
To: FreedomOwnersGroup@yahoogroups.com
Subject: [FreedomOwnersGroup]
Perkins 4.108 with Sherwood G-65 raw water pump




I have a
Perkins 4.108 with a Sherwood G-65 raw water pump. I just
rebuilt the pump because it was badly leaking. The seal was
compressed sideways because the bearings were done. Fortunately no
water had entered the engine along the drive shaft of the pump.

I ordered a rebuild kit in the US,
couldn’t find one on stock here in
Europe.

It wasn’t easy to get the two ball bearings off the shaft without the
proper tools; I damaged the shaft end a bit and had to grind it in
shape again. Inside the pump is a half moon between inlet and outlet
called ‘cam’. What struck me as odd is the fact that the cam is
screwed to the inside of the body through a too large hole without
seal. On the pump drawing they suggest to seal it with epoxy or
locktite (they use the brand name Permatex). Not a real nice
engineering solution, I feel, but with instantly curing thick epoxy
it seems to work.

What I noticed for the first time, is that the pump is mounted upside
down against the Perkins block. The cam in the pump body is usually
on top, here it’s at the bottom of the pump. The cam screw is
therefore also on the bottom and cannot be used as a bleeder for the
pump. Yes you need to bleed this pump, which I’ve never heard before.
Perhaps that’s because the inlet and outlet are at the bottom of the
pump body too, therefore air gets trapped in the upper part of the
pump. The only way to bleed it is to loosen all four screws on the
front plate, start the engine (water gushing around all over the
engine room) and then tighten the screws, the top one last. Only
after doing this, I got water out of the exhaust.







Attachment: (image/jpeg) image001.jpg [not stored]

4

Posted by michel.capel (michel.capel@…>)

Thanks Robert,

And I think we don’t mind to have industry professionals commenting
on this board. It’s a good thing to know they have certain business
interests.

On the pump: I used silicone grease on the inside of the pump and the
impeller. The front plate is indeed worn in a bit, but the spout of
water out of my exhaust makes me believe the pump still has enough
capacity. These simple, flat front plates are not cheap either, so
when it really gets worn in badly, I will probably turn it inside out.

best,
Michel


— In FreedomOwnersGroup@yahoogroups.com, “Robert” <robert@…>
wrote:

Ooops, I replied to this message from my work computer and forgot
to delete
the automatic signature. My sincere apologies.

Regards

Robert

From: FreedomOwnersGroup@yahoogroups.com
[mailto:FreedomOwnersGroup@yahoogroups.com] On Behalf Of Robert
Sent: Thursday, August 21, 2008 3:13 PM
To: FreedomOwnersGroup@yahoogroups.com
Subject: RE: [FreedomOwnersGroup] Perkins 4.108 with Sherwood G-65
raw water
pump

Michel,

You may also have to replace the cover plate on the pump as this is
also an
item that wears and this can also give priming problems. To
guarantee pump
priming, even on new engines the pumps impellers are usually given
a liberal
coating of petroleum jelly (Vaseline) or similar and normally a
small sachet
of this is included with replacement impeller kits.

Best Regards

Robert Furborough

PO Box 5, Arapahoe, NC 28510

www.betamarine. http://www.betamarine.net/ net

(877) 227-2473

(252) 249 2473

From: FreedomOwnersGroup@yahoogroups.com
[mailto:FreedomOwnersGroup@yahoogroups.com] On Behalf Of
michel.capel
Sent: Thursday, August 21, 2008 3:05 PM
To: FreedomOwnersGroup@yahoogroups.com
Subject: [FreedomOwnersGroup] Perkins 4.108 with Sherwood G-65 raw
water
pump

I have a Perkins 4.108 with a Sherwood G-65 raw water pump. I just
rebuilt the pump because it was badly leaking. The seal was
compressed sideways because the bearings were done. Fortunately no
water had entered the engine along the drive shaft of the pump.

I ordered a rebuild kit in the US, couldn’t find one on stock here
in
Europe.

It wasn’t easy to get the two ball bearings off the shaft without
the
proper tools; I damaged the shaft end a bit and had to grind it in
shape again. Inside the pump is a half moon between inlet and
outlet
called ‘cam’. What struck me as odd is the fact that the cam is
screwed to the inside of the body through a too large hole without
seal. On the pump drawing they suggest to seal it with epoxy or
locktite (they use the brand name Permatex). Not a real nice
engineering solution, I feel, but with instantly curing thick epoxy
it seems to work.

What I noticed for the first time, is that the pump is mounted
upside
down against the Perkins block. The cam in the pump body is usually
on top, here it’s at the bottom of the pump. The cam screw is
therefore also on the bottom and cannot be used as a bleeder for
the
pump. Yes you need to bleed this pump, which I’ve never heard
before.
Perhaps that’s because the inlet and outlet are at the bottom of
the
pump body too, therefore air gets trapped in the upper part of the
pump. The only way to bleed it is to loosen all four screws on the
front plate, start the engine (water gushing around all over the
engine room) and then tighten the screws, the top one last. Only
after doing this, I got water out of the exhaust.