Luck 'o' the Irish

johnny

New member
May 10, 2011
8,287
9
3
I don't know if I've good or bad luck. On arriving at the RV camp on the Anniston Army Depot I saw oil dripping from the front of the coach. Opened
the hatch, fired it up, and in the time it took to see the catastrophic leak and run back and shut it down it put a couple of quarts on the ground.
The inlet pipe to the outboard oil cooler has failed. Had it failedion the road the engine would likely be toast. I bypassed the cooler with a three
dollar union from Lowes. Only problem now - I have to run it home this evening in 90+ temps and I 20 had construction backup Friday on the trip here
for five miles or so . I will likely wait till tonight to leave for cooler temps and less stop and go traffic. The radiator oil cooler has been open
since it was recored, hence I can't just hook it up for the trip. It will need to be flushed to make sure it's still clean.

This is the second add - on cooler whose installation has failed... the one on the transmission resulted in a cooked set of clutches. More and more I
tend to believe those who said GM knew what they were doing. We need to be very careful about 'upgrades' to avoid a smoking hole in our collective
foot.

--johnny
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
Johnny,
A photo showing exactly what failed, and how you had it installed might help the rest of us identify the cause and avoid a catastrophe on our own cosches.

Sometimes it is just a minor issue overlooked during installation that can make all the difference in the lifespan of the components. The automakers spend big $$ testing to uncover weaknesses that might not appear obvious at first. Why would we expect our untested efforts to have any better success?

Les Burt
Montreal
'75 Eleganza 26'

>
> I don't know if I've good or bad luck. On arriving at the RV camp on the Anniston Army Depot I saw oil dripping from the front of the coach. Opened
> the hatch, fired it up, and in the time it took to see the catastrophic leak and run back and shut it down it put a couple of quarts on the ground.
> The inlet pipe to the outboard oil cooler has failed. Had it failedion the road the engine would likely be toast. I bypassed the cooler with a three
> dollar union from Lowes. Only problem now - I have to run it home this evening in 90+ temps and I 20 had construction backup Friday on the trip here
> for five miles or so . I will likely wait till tonight to leave for cooler temps and less stop and go traffic. The radiator oil cooler has been open
> since it was recored, hence I can't just hook it up for the trip. It will need to be flushed to make sure it's still clean.
>
> This is the second add - on cooler whose installation has failed... the one on the transmission resulted in a cooked set of clutches. More and more I
> tend to believe those who said GM knew what they were doing. We need to be very careful about 'upgrades' to avoid a smoking hole in our collective
> foot.
>
> --johnny
> --
> 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga.
> "I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Johnny,
Why not just remove the adapter from the engine block and replace the oil filter and then drive conservatively till you get home?
HTH
Nelson Wright
Belle Isle Fl & Topton NC
78 Royale rear bath

Sent from my iPhone
Nelson Wright

Orlando Fl.

>
> Johnny,
> A photo showing exactly what failed, and how you had it installed might help the rest of us identify the cause and avoid a catastrophe on our own cosches.
>
> Sometimes it is just a minor issue overlooked during installation that can make all the difference in the lifespan of the components. The automakers spend big $$ testing to uncover weaknesses that might not appear obvious at first. Why would we expect our untested efforts to have any better success?
>
> Les Burt
> Montreal
> '75 Eleganza 26'
>
>

>>
>> I don't know if I've good or bad luck. On arriving at the RV camp on the Anniston Army Depot I saw oil dripping from the front of the coach. Opened
>> the hatch, fired it up, and in the time it took to see the catastrophic leak and run back and shut it down it put a couple of quarts on the ground.
>> The inlet pipe to the outboard oil cooler has failed. Had it failedion the road the engine would likely be toast. I bypassed the cooler with a three
>> dollar union from Lowes. Only problem now - I have to run it home this evening in 90+ temps and I 20 had construction backup Friday on the trip here
>> for five miles or so . I will likely wait till tonight to leave for cooler temps and less stop and go traffic. The radiator oil cooler has been open
>> since it was recored, hence I can't just hook it up for the trip. It will need to be flushed to make sure it's still clean.
>>
>> This is the second add - on cooler whose installation has failed... the one on the transmission resulted in a cooked set of clutches. More and more I
>> tend to believe those who said GM knew what they were doing. We need to be very careful about 'upgrades' to avoid a smoking hole in our collective
>> foot.
>>
>> --johnny
>> --
>> 76 26' Eleganza(?) with beaucoup mods and add - ons.
>> Braselton, Ga.
>> "I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Why not? Because it was sitting in a military RV camp and I wasn't prepared to spend time doing something I'd just have to undo when I got home.
The adapter is cheaper and easier.

As to mounting, I'm not gonna put the thing back just to take a picture. The failure is a blowout on the inlet pipe, I'll put up a picture of it
eventually. You wouldn't believe how much oil could come out of such a little opening. It was mounted on the driver's side of the radiator frame,
vertically with the fan towards the centwer of the coach. Neither of the lines were under stress when I took them off, and I don't think it could
vibrate relative to thew lines given the way it was installed. The hole is indicative of a blowout as opposed to a crack. It isn't at a joint, it's
in the side of a pipe.

--johnny
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
Update - ran home without problems. I kept it around 55 and the poil remp stayed reasonable. A set of J,R,s lines will be next before I take it to
Augusta. I'll back flush the oil cooler in the radiator through a piece of linen. If I find anything, out somes the radiator and I'll let Sims clean
it out.

--johnny
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
Johnny,

I've been running my GMC without an oil cooler for years. With regular non-synthetic oil too. Still, the original 455 runs fine.

The factory cooler adapter always had a slight drip so after replacing the gasket several times with everything that has been recommended here I
solved the problem for good. The cooler adapter, tubing, and flex hoses are now hanging on the garage wall.

I installed an oil temp gauge on the oil filter and have found that the oil generally runs about 25 to 35 degrees over water temp when at highway
speeds, noticeably cooler in stop and go traffic.

I don't tow a car or climb mountains (except for a trip to Gainesville/Lake Lanier a few years ago). I mostly drive around Florida where it's pretty
much flat. The hottest weather I've run the GMC in was 102 in south GA and 106 in Santee SC (according to the tv weather that night) and, if I
remember correctly, the oil was running about 250 and water about 210 at highway speed (65 to 70). The GMC hasn't been in weather that hot since that
SC trip.

As a side note, this is with a non-GMC-motorhome radiator. That's another story.

The original 455 still runs fine. What am I doing wrong?
--
Bob Heller
1974 X-Canyonlands 26ft
Original 455 exc for timing chain,
Rockwell intake, valve covers. 144k miles.
Winter Springs FL
 
Congrats on the successful trip home.

> ... As a side note, this is with a non-GMC-motorhome radiator. That's another story.

Nope, just can't let that one sit there. Do tell...make, model, modifications...
--
76 Birchaven - "Wicked Mistress" - New engine, trans, alum radiator, brakes, Sully airbags, fuel lines, seats, adult beverage center... those Coachmen
guys were really thinking about us second hand owners by including that beverage center...
Columbia, SC.
 
Ditto. I know several folks who've done away with all the oil cooler
rigamaroe with no ill affects.

bdub

> Johnny,
>
> I've been running my GMC without an oil cooler for years. With regular
> non-synthetic oil too. Still, the original 455 runs fine.
>
> The factory cooler adapter always had a slight drip so after replacing the
> gasket several times with everything that has been recommended here I
> solved the problem for good. The cooler adapter, tubing, and flex hoses
> are now hanging on the garage wall.
>
> I installed an oil temp gauge on the oil filter and have found that the
> oil generally runs about 25 to 35 degrees over water temp when at highway
> speeds, noticeably cooler in stop and go traffic.
>
> I don't tow a car or climb mountains (except for a trip to
> Gainesville/Lake Lanier a few years ago). I mostly drive around Florida
> where it's pretty
> much flat. The hottest weather I've run the GMC in was 102 in south GA and
> 106 in Santee SC (according to the tv weather that night) and, if I
> remember correctly, the oil was running about 250 and water about 210 at
> highway speed (65 to 70). The GMC hasn't been in weather that hot since that
> SC trip.
>
>
 
Bobby was it you I stopped in Gainesville one day in a shopping center lot to have a look? Nice coach. I normally have a tow behind because I do dog
shows and don't always stay at the venue. Pulling Culowee Mountain to East TN or MontEagle to Gnashville, I suspect the oil will boil without the
cooler. I can get it to stay dry with the proper hoses and seals, I think I'll go in that direction.

--johnnyu
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
Johnny,

Yep, that was me. If I remember correctly, on that trip we had rented a house on Lake Lanier and had a "family reunion" that week. It's a beautiful
area, you must enjoy living there.

If you've got an oil temp gauge, see what happens when you climb some hills without the oil cooler connected. Especially in cooler weather, you might
find that the oil cooler isn't really needed. If the oil gets into the 250-260 range for long periods then the oil cooler may be necessary but my
guess is that unless you are running at high power for extended lengths of time you won't have any problems. The REAL problem is that if an oil line
breaks and the oil sprays out then you have the possibility of a fire or, at worst, the engine goes 'bang'.

Joe,

The radiator I am currently using is a Spectra CU730, fits 73-86 Chevy C30 and many other GM pickups and suburbans of that vintage. It's a very common
radiator available seemingly everywhere for about $125. Other brands have different model numbers but they always end with '730'. If I wanted a
radiator with more cores (if I were climbing mountains with a towd on the back of the GMC) there are other options, such as mmrad-ck-78x by Mishimoto
for about $325 but so far the 2 core Spectra is working fine for me. Compared to the stock GMC rad, the '730' rad is the same width, same hose
locations, and about 5 inches shorter height. I only use the rad to cool the engine coolant. I have no engine oil cooler. The trans is cooled by a
Long Tru-Cool LPD-47391 (which is way more trans cooling than I would ever need) connected by 3/8" hard line, no rubber anywhere in the trans circuit.
This way there is no chance of ever getting coolant in the transmission. Easily replaceable and bypassable in case something hits it. The radiator is
mounted in the GMC rad frame and held up by a couple of 4 inch angle brackets which attach to a piece of 5/4 decking board cut-to-fit. The open space
from the bottom board to the bottom of the GMC rad frame is covered by some roofing sheet metal.

That's the basics. Gotta go!
--
Bob Heller
1974 X-Canyonlands 26ft
Original 455 exc for timing chain,
Rockwell intake, valve covers. 144k miles.
Winter Springs FL