Home » Public Forums » GMCnet » [GMCnet] Fuel "Burp" Line
| [GMCnet] Fuel "Burp" Line [message #130898] |
Sun, 19 June 2011 15:09  |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma:
|
Senior Member |
|
|
I mentioned in my earlier posting about transmission leakage that
Stick had a leaking "burp" hose to replace. Ever since he's had the
coach, he's complained about fuel smell in the cockpit, especially
after refueling. I was with him recently when he refueled and watched
inside the driver's wheel well while he pumped the gas. As soon as
the tank approached full, an 8" long line of gasoline erupted from a
crack in the 1/2" x 27" rubber hose connecting the steel lines above
and below.
When Stick removed the line yesterday, as soon as he twisted the hose
to break it loose from the steel line, it immediately broke entirely
off in his hand. On both ends.
Expecting to find an unrated hose when I examined it closely, I was
surprised to find the legend GM 6107M, which is their equivalent to
SAE J30R6. It was obvious from the disparate hose clamps on Stick's
coach that the hose was not original, and GM 6107M was not published
until 1980. If we assume that replacement wasn't required for maybe
20 years after the coach was built, that says the hose was <15 years
old. Pretty old, but old enough to crumble in one's hand???
This experience makes me even more anxious to replace all of my rubber
fuel lines, installed 12 years ago. Ignorant as I was then of the
significance of the forthcoming ethanol disaster, I have no idea what
the ratings of my hoses are.
GM 6107M has now been replaced by GM 6165M, corresponding to SAE
J30R7, rated for up to 50 psi and supposedly ethanol-safe.
In researching all this I kept finding references to "sour gas", which
I didn't know what was until I came across this site:
http://www.acdelcotechconnect.com/pdf/tsb/tsb_fuel_line.pdf
Here's a quotation: "The laminated tube helps resist cracking caused by
“sour gas,” which forms when unused gas is returned to the fuel tank."
Now that's a new one on me. Sounds like we're degrading our own
gasoline just by recirculating it. Now I wonder about the wisdom of
that Toronado pump, and even more about our high pressure EFI pumps
which produce far more pressure than the <20 psi most of us actually
run through the Throttle Body (TB).
Notice in that article that even they are waffling about 30R7:
"At times, more aggressive fuels can extract the oils that give SAE 30R7
hose its flexibility. Engineers caution that the result can be a brittle, stiff
tube that could greatly reduce the performance and service life of the hose"
Availability is another issue: When Stick tried to find the 1/2" 30R7
to replace his burp hose, there was none in town. And no one even
knew what "30R7" meant. (Though the fact is, from my own examination
of their inventories, that's what they stock) And I'd learned a week
or so earlier that no one had any idea what 30R9 is -- nor do they
have any. O'Riley's at least said "I can order 'fuel injection'
hose."
What I'm trying to say is, "Learn about the available fuel hoses
'cause you ain't gonna get no help at a local store -- at least not in
Americus at CarQuest, NAPA, Advance, O'Riley, or AutoZone -- our
complete selection." Even online is disappointing: Jegs, for example
blatantly advertises their "universal fuel hose" as suitable for use
with carburetors because it "even exceeds 30R6"! Gosh, I'd sure hope
so! But probably will last less than a year with ethanol.
And Summit Racing mentions 30R9 in their ad for Dayco Fuel Injection
hose only in the small print. You'd think that a price of $54.95 for
10' of 3/8" hose they'd offer a little more promotion. :-)
Probably the best thing to do is call one of the Jim's. I didn't
discuss this with JimK when I talked to him the other day, but I
suspect he carries at least 30R7 and hopefully 30R9 in 1/2" ID for the
"burp hose". It's highly unlikely that you'll find hose that large in
stock at any local parts store unless they perhaps cater to heavy
truck services. I believe the burp line is the only place it's used
on the GMC. I'm sure both Jim's will have the 5/16" and 3/8" sizes
that are more commonly used.
The AC Delco reference above pretty well summarizes what I learned,
except the warning: If it's not mentioned, DON'T use it.
For my part, I intend to replace as much fuel line as possible with
steel and attempt to use 30R9 for any needed hoses -- despite its cost
HTH,
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
Current Time: Fri Oct 11 04:27:35 CDT 2024
Total time taken to generate the page: 0.01591 seconds
|
GMCforum
Search
Help
Register
Login
Home
