Water Pump

hemogoblin

New member
Jul 9, 1998
138
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A new Water Pump was mentioned from Eaton GMC.
Anybody know if this was one with a cast impeller of 4 inches or 4 and one
quarter inches? Does it make a difference? Which one does Cinnebar stock?
I'm planning to carry a spare but I want the correct one.
thanks
Mark '77 Palm Beach NY
Hemogoblin's.com
 
Mark,
I just completed a job which included a new water pump. I ordered a new
one through GM and recieved a steel impeller that was 3 1/2". I then
ordered a rebuild and told my supplier to open the boxes and tell me the
size of the impeller. He came back and said he had ones on the shelf with
the same number with cast & stamped impellers, how about that! The OEM
impeller on the water pump I pulled out was a 4" cast one.

My sources do not have a special # for the larger impeller, it seems to be
a matter of luck.

I will have my suppliers check before they ship in the future!

Jim Bounds www.gmccoop.com
- --------------------------

>A new Water Pump was mentioned from Eaton GMC.
>Anybody know if this was one with a cast impeller of 4 inches or 4 and one
>quarter inches? Does it make a difference? Which one does Cinnebar stock?
>I'm planning to carry a spare but I want the correct one.
>thanks
>Mark '77 Palm Beach NY
>Hemogoblin's.com
>
>
>
 
Hey Man,
I've always been here but I've been so burried with new work and the
hundreds of direct Emails that I have had a hard time staying awake enough
to get into any of the net threads. Sorry bout that chief!

Does the pump fit, does it line up, gasket surfaces mate, offset of the
shaft measure right and heater hose complement correct? Well the "Bookem
Danno".

One bobo I ran into on the last job was the gasket did not follow the mate
surface at the to and left a gap, yes it did leak and yes we did have to go
back in and change the gasket, bummer. The time chain set had several
water pump gaskets to choose from so we had the prob. solved OK, but really
check that out.

Hope this helps,

Jim bounds
- --------------------------

>Jim
>
>Nice to see you back. Glad you care about us-----nobody else seems
>to. The other day I found a water pump in my motorhome. It does not have
>the right casting #s on the housing but it does have a 4 1/4 inch
>cast impeller. Do I keep it or throw it away?
>
>Take Care
>Arch
>
>>
>> Mark,
>> I just completed a job which included a new water pump. I ordered a new
>> one through GM and recieved a steel impeller that was 3 1/2". I then
>> ordered a rebuild and told my supplier to open the boxes and tell me the
>> size of the impeller. He came back and said he had ones on the shelf with
>> the same number with cast & stamped impellers, how about that! The OEM
>> impeller on the water pump I pulled out was a 4" cast one.
>>
>
>
 
> In a message dated 12/9/98 10:46:58 PM Eastern Standard Time,

>
> > My sources do not have a special # for the larger impeller, it seems to be
> > a matter of luck.
>
> I had the same problem in finding my water pump. I tried Napa , they carry
> water pumps, however after 3 trys of delivering the stamped steel water pump,
> I went to a different auto parts store. This time I specifically asked that
> they open the boxes, explained that I wanted a cast iron impeller. They had
> two water pumps, one stamped steel and the other cast iron. Mind you they all
> had the same number. The counterman did not realize that this could be
> possible. So I agree with Jim Bounds---- It seems to be a matter of luck---
> But this luck would improve if you would have them open the box first before
> trecking to the parts store.
>
> Scott Nehoda Adohen
> http://www.bytedesigns.com/nehoda t=_self]HEINZ NEHODAS BACK YARD[/url]

I went through the same thing 9 months ago and found that there are several
variations of the cast iron impeller and the size of the cavity in the pump
housing. Also critical is the clearance between the blades and the housing. The
tighter the better so you get less bypass. Just remember, just because you find a
cast impeller version, doesn't mean it's any good for the GMC. Best to find and
use an original motorhome housing and have it rebuilt with super heavy duty seals,
etc.

Phil Swanson
 
Hate to recommend the obvious but why not just use the approved sources that
we know furnish the correct cast iron pump. Gateway has the correct cast
iron pump for $73. at 1-800-654-0374. Ray Curtins has them at
1-800-764-3673 for $49.95 plus $10 core charge. I am sure that Cinnabar and
Buskirk etc has them also. any other method seems to me to be hit and miss.

>
>

>
>> In a message dated 12/9/98 10:46:58 PM Eastern Standard Time,

>>
>> > My sources do not have a special # for the larger impeller, it seems to be
>> > a matter of luck.
>>
>> I had the same problem in finding my water pump. I tried Napa , they carry
>> water pumps, however after 3 trys of delivering the stamped steel water pump,
>> I went to a different auto parts store. This time I specifically asked that
>> they open the boxes, explained that I wanted a cast iron impeller. They had
>> two water pumps, one stamped steel and the other cast iron. Mind you
they all
>> had the same number. The counterman did not realize that this could be
>> possible. So I agree with Jim Bounds---- It seems to be a matter of luck---
>> But this luck would improve if you would have them open the box first before
>> trecking to the parts store.
>>
>> Scott Nehoda Adohen
>> http://www.bytedesigns.com/nehoda t=_self]HEINZ NEHODAS BACK YARD[/url]
>
> I went through the same thing 9 months ago and found that there are several
>variations of the cast iron impeller and the size of the cavity in the pump
>housing. Also critical is the clearance between the blades and the
housing. The
>tighter the better so you get less bypass. Just remember, just because you
find a
>cast impeller version, doesn't mean it's any good for the GMC. Best to
find and
>use an original motorhome housing and have it rebuilt with super heavy duty
seals,
>etc.
>
> Phil Swanson
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
 
Thanks for all the info on Water Pumps. I have read the article in GMCMM,
Eaton no longer carries the 4 and one quarter impeller model. I still wonder
if Cinnebar "original GM parts" is that size or another. Has anyone removed
an original OEM Pump and measured the impeller?
I purchase most parts mail order, local suppliers frown after I refuse
first three items they pull down. Return UPS costs get high when I return
items. I try to research before I order and this Digest seems to do a really
great job for me. Thanks Patrick!
Mark '77 Palm Beach L.I.N.Y.
 
Last summer I ordered a heavy duty waterpump from Winterfeld.
It turned out to be a TRW FP-1524HD. Both of these are listed in the
GMCMI Parts Interchange Index. I suggest that you stick with this and
forget NAPA etal. When my engine was replaced by the factory many
years ago (long story) the wrong waterpump ended up on the engine and
I suffered many years of overheating. I think that problem is gone now.

BTW, a word of warning. The waterpump is mounted on a plate. The top
of the plate is not fastened to the engine. In removing the
waterpump I missed a small bolt holding the pump to the plate.
I thought the pump was just stuck to the plate and in encouraging its
separation managed to break the seal between the plate and the block.
I did not know this until everything was back together and I had
coolant in the crankcase. It is impossible to replace the gasket
between the plate and block without a lot of work so I tried a liberal
amount of sealer. It seems to be holding. Probably not the first or
last to do this but it does seem like a bad design not to secure the
plate to the block

Does this qualify for confessing a dumb mistake ?

Ted Schurman
73 Glacier VA

>
> In a message dated 12/9/98 10:46:58 PM Eastern Standard Time,

>
> > My sources do not have a special # for the larger impeller, it seems to be
> > a matter of luck.
>
> I had the same problem in finding my water pump. I tried Napa , they carry
> water pumps, however after 3 trys of delivering the stamped steel water pump,
> I went to a different auto parts store. This time I specifically asked that
> they open the boxes, explained that I wanted a cast iron impeller. They had
> two water pumps, one stamped steel and the other cast iron. Mind you they all
> had the same number. The counterman did not realize that this could be
> possible. So I agree with Jim Bounds---- It seems to be a matter of luck---
> But this luck would improve if you would have them open the box first before
> trecking to the parts store.
>
> Scott Nehoda Adohen
> http://www.bytedesigns.com/nehoda t=_self]HEINZ NEHODAS BACK YARD[/url]