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| [GMCnet] water pump? [message #338296] |
Fri, 02 November 2018 13:06  |
Ek_Lektro
Messages: 167
Registered: March 2011
Karma: 2
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hey GMC friends, I’ve discovered some intermittent coolant leakage, most noticeable after getting home from a drive and turning off the engine. Its difficult to see where it is coming from, but i can see a little bit of coolant on the inside of the fan pulley, dripping down from there. so I am guessing this is the water pump starting to leak from the internal seal? Can anyone recommend the best pump to get for a 1976 455 engine? do our coaches require something different than the standard Oldsmobile Toronado replacement pump? anything else recommended to replace while we are in there? (20 years of owning GMCs and never had to replace one, always something new!) Thanks!
Greg Weber
Los Angeles
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| Re: [GMCnet] water pump? [message #338297 is a reply to message #338296] |
Fri, 02 November 2018 13:35  |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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I think most will tell you, if you are taking everything apart to get to the water-pump, go a little further and change the timing chain, if it has never been changed. the timing chain is not too difficult to get to, beyond the water pump.
timing chain is some extra work, as you really need to remove the shroud, fan/clutch. then lift the engine up to get the front mount off. as well as all the hassle of making sure timing marks are correct(use a straight edge), and getting the timing cover in place with the lower seal. But many have loose OEM timing chains.
here is the waterpump I just installed in my 455:
https://www.summitracing.com/oh/parts/aaz-55-21118h/overview/
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: [GMCnet] water pump? [message #338321 is a reply to message #338297] |
Sat, 03 November 2018 11:39 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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That is the pump that you want. Make sure that the part number ends in H. Do not let anyone substitute another brand. It is available many places including Jim K, Rock Auto, or Cardone direct online.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] water pump? [message #338349 is a reply to message #338296] |
Sun, 04 November 2018 13:12 |
Ek_Lektro
Messages: 167
Registered: March 2011
Karma: 2
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Thanks John, Bob and Ken,
OK, i’ll be getting this pump then: Cardone Industries 55-21118H
> https://www.summitracing.com/oh/parts/aaz-55-21118h/overview/
Its nice to get a clear consensus of opinions, thanks
As to the timing chain, hmmm… My guess is that its NOT the original plastic cam, but i’m not 100% sure.
I bought the coach in 2002 from Dennis Richardson / GMC-RV in Industry CA, with a fresh rebuilt engine
and that was 53,000 miles ago.
(Being new to GMC’s back then, and with the coach being a lien sale, i’m not sure exactly who rebuilt the engine,
and so we’re not 100% sure that whoever rebuilt the engine replaced the timing chain!…
but i’d imagine they’d have to be crazy NOT to replace it).
Anyway, regardless, If we know that the chain is at least 17 years and 53,000 miles old,
then does the safe money say to replace it (while we’re kinda already in there)??
well, the plot thickens a bit:
If the job was limited to just the water pump, then I was figuring i'd get the work done
at a trusted mechanic’s shop down in Tijuana, next week.
But if we’re adding a timing chain to the mix, hmmm…
Its not like the parts prices or Tijuana-priced labor will be all that expensive.
Its more a question of making sure they do the job 100% correctly; Plus, camping out down there while they do the work.
(My coaches are the only GMCs they’ve ever worked on, but… its just an Old Toronado when it comes down to it, right? ha!)
> timing chain is some extra work, as you really need to remove the shroud, fan/clutch. then lift the engine up to get the front mount off. as well as all the hassle of making sure timing marks are correct(use a straight edge), and getting the timing cover in place with the lower seal.
> The roller chain is great for race applications. With high RPM's, and high valve spring pressures. The chain/sprockets sets are about $35. Gasket/seal set is about $16.
I recall the double roller chain being what Miguel used in my 403 Eleganza last year.
(I wish i could afford to have Miguel/MGM do ALL my coaches work!)
Do you recommend the same double roller in a 455?
Anyway,… the overview:
The water pump leak has been pretty minor, having to add maybe a quart of coolant to the reservoir tank
every 100 miles or so. Its my understanding that this leak is basically the pump’s internal seal starting to go.
Given the nature of how exactly the pump's seals fail,
is it safe to say that maybe i can put this work off for another few thousand miles of vigilant driving?
Or... Could the leak open up all of a sudden, and then i’m over-heating and stranded, or risking blowing the engine?
The temptation to put the job off til next spring is pretty strong. But… getting things out of the way is also tempting
Thanks for reading, and many thanks for any further experienced advice!
Cheers
Greg Weber / SolarSonic / Los Angeles
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| Re: [GMCnet] water pump? [message #338352 is a reply to message #338349] |
Sun, 04 November 2018 14:30 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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They seep until they let coolant into the bearings, displacing the lube.
Then the bearings fail. Don't know if there is a timeline for this, but,
you have already been warned. Heed it, or not. Your choice. Fix it at home
or on the road, your choice.
I put one in, next to the last time out. $360.00 tow, Overnight
campout in tow yard, cost yet to be determined as it was Judy's birthday.
$20.00 cab ride to pick up the new water pump. $300.00 to have 2 guys stop
what they were doing and install the pump. The pump was new ball and roller
design. Less than $50.00. New Anti-freeze, thermostat, radiator cap, gasket
, lower hose, belts, etc.
Jim Hupy
Salem, Or
On Sun, Nov 4, 2018, 11:13 AM Ek_Lektro wrote:
> Thanks John, Bob and Ken,
>
> OK, i’ll be getting this pump then: Cardone Industries 55-21118H
>> https://www.summitracing.com/oh/parts/aaz-55-21118h/overview/ https://www.summitracing.com/oh/parts/aaz-55-21118h/overview/>
> Its nice to get a clear consensus of opinions, thanks
>
> As to the timing chain, hmmm… My guess is that its NOT the original
> plastic cam, but i’m not 100% sure.
> I bought the coach in 2002 from Dennis Richardson / GMC-RV in Industry
> CA, with a fresh rebuilt engine
> and that was 53,000 miles ago.
> (Being new to GMC’s back then, and with the coach being a lien sale, i’m
> not sure exactly who rebuilt the engine,
> and so we’re not 100% sure that whoever rebuilt the engine replaced the
> timing chain!…
> but i’d imagine they’d have to be crazy NOT to replace it).
> Anyway, regardless, If we know that the chain is at least 17 years and
> 53,000 miles old,
> then does the safe money say to replace it (while we’re kinda already in
> there)??
>
> well, the plot thickens a bit:
> If the job was limited to just the water pump, then I was figuring i'd get
> the work done
> at a trusted mechanic’s shop down in Tijuana, next week.
> But if we’re adding a timing chain to the mix, hmmm…
> Its not like the parts prices or Tijuana-priced labor will be all that
> expensive.
> Its more a question of making sure they do the job 100% correctly; Plus,
> camping out down there while they do the work.
> (My coaches are the only GMCs they’ve ever worked on, but… its just an
> Old Toronado when it comes down to it, right? ha!)
>
>> timing chain is some extra work, as you really need to remove the
> shroud, fan/clutch. then lift the engine up to get the front mount off.
> as well as all the hassle of making sure timing marks are correct(use a
> straight edge), and getting the timing cover in place with the lower seal.
>
>> The roller chain is great for race applications. With high RPM's, and
> high valve spring pressures. The chain/sprockets sets are about $35.
> Gasket/seal set is about $16.
>
> I recall the double roller chain being what Miguel used in my 403 Eleganza
> last year.
> (I wish i could afford to have Miguel/MGM do ALL my coaches work!)
> Do you recommend the same double roller in a 455?
>
> Anyway,… the overview:
> The water pump leak has been pretty minor, having to add maybe a quart of
> coolant to the reservoir tank
> every 100 miles or so. Its my understanding that this leak is basically
> the pump’s internal seal starting to go.
> Given the nature of how exactly the pump's seals fail,
> is it safe to say that maybe i can put this work off for another few
> thousand miles of vigilant driving?
> Or... Could the leak open up all of a sudden, and then i’m over-heating
> and stranded, or risking blowing the engine?
> The temptation to put the job off til next spring is pretty strong. But…
> getting things out of the way is also tempting
>
> Thanks for reading, and many thanks for any further experienced advice!
> Cheers
> Greg Weber / SolarSonic / Los Angeles
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: [GMCnet] water pump? [message #338354 is a reply to message #338296] |
Sun, 04 November 2018 15:19 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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If your engine is rebuilt it most likely has steel cam gear not nylon. The price on that recommended Cardone pump is so low it scares me, but supposedly the best bet!
John Lebetski
Woodstock, IL
77 Eleganza II
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