OldHillwalker

Two weeks ago my 1999 K1500 Suburban blew the ****** end fitting from the 10 inch section of flexible fuel line (SUPPLY LINE) located just under the driver’s side door.All the fuel lines were completely replaced last summer along with the fuel filter.The fuel tank and pump are three years old and the two roll-over vents in the tank were replaced as well.I replaced the old tubular crimped fitting with two extreme duty hose clamps and reinstalled the line.I then took a fuel pressure reading at the monitoring port up near the throttle body and it read 55 psi (normal).The truck then ran well for two weeks until this morning when it happened again, this time the other fitting blew out on the flex line.
I’m suspecting that the fuel pressure regulator is malfunctioning and letting the fuel pressure get way too high.However, before removing the upper intake manifold and exposing the fuel distribution spider so that I can replace the FPR I thought I would post this here to see if anyone has had this experience.
The truck has no rust, only 26k on the tranny and engine, stainless steel exhaust system, new radiator, and it’s a keeper so I really need to fix this.

sledge.impy

Let's step back a second.

This flexible fuel line section , is that how it was factory? Or was there metal lines in that section?

Can you post some pictures?

This also worries me - "replaced the old tubular crimped fitting with 2 extreme duty hose clamps and reinstalled the line." Maybe that's why it was like that from factory, not with extreme duty hose clamps, because it won't hold.

Why were the fuel lines replaced in the first place?

OldHillwalker

The lines were replaced due to being nearly rusted through, as well as the brake lines. Replacement was a complete factory replacement set.
The two hard lines that run from the fuel distribution (spider) block in the upper manifold (plenum) go down to a paired connection bracket near the bell housing and connect to two hard lines that run another foot or so. At that point they connect to two flexible rubber lines about 19 inches long which then connect to two hard lines which run back to the fuel tank. At the fuel tank the hard lines connect to two flexible lines with quick connects at each end. These go to the fuel pump. The rubber line terminated a both ends with a metal single ****** pipe fitting and are crimped on with a metal ferrule about 12 mm long. The metal ferrule was unable to hold the rubber line onto the metal fitting and thus the fitting was ejected, thus stalling the truck and pumping gas out onto the ground under the truck.