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Old 04-15-2009, 09:38 PM   #1 (permalink)
J-Mar
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Return lines and leaks

Who re-uses return line gaskets and who gets new ones? Any experiences with problems re-using them if they look good. Seems like they could be re-used at least once as the tork spec is only 8 lbs. I'm speaking of the under valve cover return line gaskets at each injector and the one banjo bolt gasket going into the head.

Also what seems to be the wrench of choice for the high pressure lines going into the injectors. Drivers side is tight and awkward. My line wrenches wouldn't work. Do I need to get a crows foot set?
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Old 04-15-2009, 09:48 PM   #2 (permalink)
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Change them. They will leak.
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Old 04-15-2009, 10:19 PM   #3 (permalink)
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For what they cost and all the time it took to get there and return to the same spot if they leak....do you really need to think about it?
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Old 04-17-2009, 12:20 AM   #4 (permalink)
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Ok. I know this sounded cheep but I'm a contractor. No work = cheep thoughts. Point taken.

No one has any experience with best tool for high pressure fuel line nuts?
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Old 04-17-2009, 12:58 AM   #5 (permalink)
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crows foot seems to work best, unless you can find or make a socket that will work.
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Old 04-18-2009, 12:09 AM   #6 (permalink)
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Crows foot especially for the ones on the drivers side.
Another option is to remove wheel/liner and get the lines from down there. It also helps to have a short torque wrench.
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Old 04-25-2009, 12:47 PM   #7 (permalink)
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Just finished with replacing the rest of my injectors couple days ago. Took the advise and bought new return line gaskets. Everything seemed to go smooth. I was very careful to make sure everything was tight and in order.

Truck fired up and ran great. Man what a difference. Test drove it for 10 min or so and parked it for the night. Next day off to work. 10 minutes into my drive I notice the truck stumbling at idle. About this time I notice my fuel gage is very low (had a 1/4 tank when I left for work). Barely made it home without running out of fuel. Pouring fuel and oil out of every orifice! Needless to say I was rather bummed. Given that no codes came up and the engines performance was still good I figured the leak had to be in the return side. Looked at the banjo fittings where the return comes out of each head. I was thinking about making up a fitting to either pressurize or pull vacuum at each side in order to narrow down which side was leaking. Well given the location of both banjo fittings (who in the heck gets to the drivers side one for return rate test?!?!) and the fact that my back was not feeling great at this point I abandoned that idea.

Started thinking and came up with a game plan...

Pulled the return fuel line apart (quick disconnect) at drivers side. Hose clamped a length of 3/8 vinyl tubing on the hard line. Hose clamped a schrader fitting on the other end of the tubing. Put a refrigerant hose on it and hooked it up to a nitrogen bottle I had (could use compressed air too I suppose). Plugged the open disconnect end of the return line with my thumb and gave the return side a shot of nitrogen. Didn't hold any pressure. Big leak! Pulled breather lines off both valve covers and gave it a shot again. Passenger side blew nitrogen out big time. Tore down that side again and found #4 injector return line gasket screwed up. I didn't see during the install that the bottom gasket got bent to the side and didn't seat at all! Put another on and put her back together.

This probably isn't a GM approved method and may not work for really small leaks but I hope this helps someone else "short cut" the leak finding mission. I KNOW I'm not the only one this has happened to or will happen to.
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Old 04-25-2009, 02:43 PM   #8 (permalink)
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Quote:
Originally Posted by RonJT View Post
Crows foot especially for the ones on the drivers side.
Another option is to remove wheel/liner and get the lines from down there. It also helps to have a short torque wrench.
Instead of using a foot lb torq wrench, would not an inch lb torq wrench do the trick (8 foot lbs = 96 inch lbs).......SWH...
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Old 04-25-2009, 04:19 PM   #9 (permalink)
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The gm manual sais 12ftlb's for return line bolt's and the one for the head is this wrong? That's what I torqued mine to.
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