What are the chances of an engine builder knowing that a GMC has a different water pump?

Bob Dunahugh

New member
Sep 17, 2012
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The previous owner had Horn Automotive rebuild the 403 in our GMC. I have known them for about 30 years. They have a very good reputation. The 403 was done by them in 1994. Then the owners drove it 1880 miles before parking the GMC in 1995 for 20 years. The paper work says new water pump. So did the 403 get the correct 6 blade impeller water pump. Not the car pump. Been running fine for the 4,000 we've put on it in 2016.. But I think I should pull the pump to check it. Bob Dunahugh
 
If you have not had any problems, why pull it? If is ain't broke, don't fix it.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
Ken

My brother always said if I had a new Mercedes, I'd want to take it apart
to see why it was running?

Mike in NS

> If you have not had any problems, why pull it? If is ain't broke, don't
> fix it.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
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--
Michael Beaton
1977 Kingsley 26-11
1977 Eleganza II 26-3
Antigonish, NS

Life is too short to hold a grudge; slash some tires and call it even !
 
> The previous owner had Horn Automotive rebuild the 403 in our GMC. I have known them for about 30 years. They have a very good reputation. The 403
> was done by them in 1994. Then the owners drove it 1880 miles before parking the GMC in 1995 for 20 years. The paper work says new water pump. So
> did the 403 get the correct 6 blade impeller water pump. Not the car pump. Been running fine for the 4,000 we've put on it in 2016.. But I think I
> should pull the pump to check it. Bob Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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Considering your "Failure is no option", If it would make you feel better, DO IT! JMHO
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
What Ken said...and with a little boy scout modification: if it ain't broke,figure out how to fix it when it does break, and get the parts you
need/want and carry them with you. Plenty of places to stash a water pump if you bag it instead of keeping it in a box. Or fill the extra space in the
box with goodies.
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.
 
> What Ken said...and with a little boy scout modification: if it ain't broke,figure out how to fix it when it does break, and get the parts you
> need/want and carry them with you. Plenty of places to stash a water pump if you bag it instead of keeping it in a box. Or fill the extra space in
> the box with goodies.

I use to tease Dan Gregg all the time about all of the stuff he carried with him in the coach. He never carried a spare engine and that is what he
blew two times.

I carry spare ignition parts which, I have used twice, and that is about it.

--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
In the 4000 miles you've already driven, have you run with no temperature issues in the most extreme conditions you're likely to encounter? If the
answer is yes, then I would leave it... If it's no, then you need to ask yourself how you feel about the possibility of having to change a water pump
in those same extreme conditions, how likely it was they used the correct water pump on the rebuild to begin with, and how well you'll sleep not
knowing if it is the correct pump. If you're answers to those questions are "not bad", "pretty likely" and "sleep like a baby", I would leave it then
too. If not....

--
Mark S. '73 Painted Desert,
Manny 1 Ton Front End,
Howell Injection,
Leigh Harrison 4bag and Rear Brakes,
Fort Worth, TX
 
For a replacement, I'd probably worry more that it has the proper bearings. Should be ball - roller, not ball - ball.

--johnny
--
'76 23' transmode Norris upfit, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"The road goes on forever, and the party never ends" --Robert Earl Keen
 
G'day,

Does anybody have a spare water pump they can look at? If yes would it be
possible to use a borescope to look into one of the the ports and count the
blades on the pump?

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces] On Behalf Of Terry
Sent: Friday, January 20, 2017 3:23 AM
To: gmclist
Subject: Re: [GMCnet] What are the chances of an engine builder knowing that
a GMC has a different water pump?

What Ken said...and with a little boy scout modification: if it ain't
broke,figure out how to fix it when it does break, and get the parts you
need/want and carry them with you. Plenty of places to stash a water pump if
you bag it instead of keeping it in a box. Or fill the extra space in the
box with goodies.
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

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Unsubscribe or Change List Options:
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I've got pumps hanging in the storage shed that I can check, but I'm
confident right now that not even a borescope is necessary if the lower
hose is removed and the belt removed so the shaft can be turned. It should
be easy to count the vanes. Not so simple to measure them though.

As for replacing the pump, Bob, I wouldn't have any more confidence in a
new pump than in an already-installed one. Eventually, they'll both leak
at the shaft; the new one might leak before the old one.

Ken H.

On Thu, Jan 19, 2017 at 5:50 PM, Rob Mueller
wrote:

> G'day,
>
> Does anybody have a spare water pump they can look at? If yes would it be
> possible to use a borescope to look into one of the the ports and count the
> blades on the pump?
>
>
 
Read here
http://bdub.net/gmcmotorhome.info/watpump.html

On Thu, Jan 19, 2017 at 3:44 PM Ken Henderson
wrote:

> I've got pumps hanging in the storage shed that I can check, but I'm
>
> confident right now that not even a borescope is necessary if the lower
>
> hose is removed and the belt removed so the shaft can be turned. It should
>
> be easy to count the vanes. Not so simple to measure them though.
>
>
>
> As for replacing the pump, Bob, I wouldn't have any more confidence in a
>
> new pump than in an already-installed one. Eventually, they'll both leak
>
> at the shaft; the new one might leak before the old one.
>
>
>
> Ken H.
>
>
>
>
>
> On Thu, Jan 19, 2017 at 5:50 PM, Rob Mueller
>

>
>
>
> > G'day,
>
> >
>
> > Does anybody have a spare water pump they can look at? If yes would it be
>
> > possible to use a borescope to look into one of the the ports and count
> the
>
> > blades on the pump?
>
> >
>
> >
>
> _______________________________________________
>
> GMCnet mailing list
>
> Unsubscribe or Change List Options:
>
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
 
The Apollo 13 theme is coming into play. The standard thermostat in our GMC's is 195 degrees. The burned GMC ran at 195 to 200 all the time ( with a 195 in it ) except on real hot summer days. Then it ran at 200. Even when towing a GVW of 21,000 lbs. As I generally check the block at different places. This 403 last summer was always at 195 to 200. Even on days in the upper 50's with rain. And at that time it had it's cooling starting at 180. Not 195. So could this mean that the water pump has the car 5 impeller pump. Both radiators are very clean inside. So is this an indication? Interesting thought. YES. I get ANAL over details. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Thursday, January 19, 2017 12:27 AM
To: gmclist
Subject: What are the chances of an engine builder knowing that a GMC has a different water pump?

The previous owner had Horn Automotive rebuild the 403 in our GMC. I have known them for about 30 years. They have a very good reputation. The 403 was done by them in 1994. Then the owners drove it 1880 miles before parking the GMC in 1995 for 20 years. The paper work says new water pump. So did the 403 get the correct 6 blade impeller water pump. Not the car pump. Been running fine for the 4,000 we've put on it in 2016.. But I think I should pull the pump to check it. Bob Dunahugh
 
Read here
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&th=17880&goto=134313&rid=0

> The Apollo 13 theme is coming into play. The standard thermostat in our
> GMC's is 195 degrees. The burned GMC ran at 195 to 200 all the time (
> with a 195 in it ) except on real hot summer days. Then it ran at 200. Even
> when towing a GVW of 21,000 lbs. As I generally check the block at
> different places. This 403 last summer was always at 195 to 200. Even on
> days in the upper 50's with rain. And at that time it had it's cooling
> starting at 180. Not 195. So could this mean that the water pump has the
> car 5 impeller pump. Both radiators are very clean inside. So is this an
> indication? Interesting thought. YES. I get ANAL over details. Bob Dunahugh
>
>
>
>
>
> ________________________________
>
> From: Bob Dunahugh
>
> Sent: Thursday, January 19, 2017 12:27 AM
>
> To: gmclist
>
> Subject: What are the chances of an engine builder knowing that a GMC has
> a different water pump?
>
>
>
>
>
> The previous owner had Horn Automotive rebuild the 403 in our GMC. I have
> known them for about 30 years. They have a very good reputation. The 403
> was done by them in 1994. Then the owners drove it 1880 miles before
> parking the GMC in 1995 for 20 years. The paper work says new water pump.
> So did the 403 get the correct 6 blade impeller water pump. Not the car
> pump. Been running fine for the 4,000 we've put on it in 2016.. But I think
> I should pull the pump to check it. Bob Dunahugh
>
> _______________________________________________
>
> GMCnet mailing list
>
> Unsubscribe or Change List Options:
>
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
 
My guess is that the seal and grease may be aged out from sitting 21 years. Without exercise. Lots of "barn find" super liow mile cars start to leak
once put into service. Especially if the same coolant was in there 21 years
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First