Im just going to do a quick write-up of how to bleed the fuel system on a 1999 6.5L turbo diesel. The process should be similar for most 6.5L, but may vary. This is a pretty simple process, but its always nice to have pictures when you are doing it your first time. (Which is what i would have liked, since i am also new) I would like to thank Mayhem for his advice throughout the past week. Without further ado, onto the topic.

This first picture is just a view of the engine bay from the drivers side fender.


Next up, you want to find your fuse box. For those of you that dont know where thats at, its right next to the brake master cylinder.


Now take the cover off the fuse box. After that, you have to remove the Fuel Pump Relay. On mine, this was the black relay at the bottom left corner.




Now that you have found the relay, and remove it, you need to open the breather on your fuel filter. Just a few quick turns to the left (Lefty Loosey, Righty Tighty) and it will be open.


Now find a peice of wire you have laying around. Doesn't need to be anything special. I used a two inch peice of 18 gauge.


You are now going to jump the fuel pump relay with this piece of wire. I tried to take a picture of the two sections to use your wire on, but it was kind of hard. So, if you look at the fuse like a U, you need to put on end of the wire in the top right, and the other end in the bottom left.


You should be able to hear the lift pump working. If you don't, you either have a wiring problem or your lift pump is shot. If you do hear the pump, within a few seconds (depending on how much air is in there) fuel should start coming out. Stop jumping the fuse, and tighten down the breather on the filter.

Your half way done! *Hopefully*

Now find the T-handle. It is located to the left of the Oil fill/cap.



Now just like the filter, your going to turn this a few turns to the left to open it up, and then go back to the fuse box and jump the relay the exact same way you did the last time. Soon you should hear fuel coming out. If its like my case, you'll hear it dripping on the ground. This is because Chevrolet put a drain hose on it.

The final picture is with me laying on the ground looking up. You can kind of see the drain hose. In the picture, its right above the two little bolt looking things in the middle

You may have to repeat this whole process to get it perfectly bleed. Hopefully this helps at least one person!

Good luck, and Happy trucking

 

A short note to make life easier for you.

On 96+ you should find a red wire with an insulator over it very near the back of the underhood fusebox.
Simply apply 12v to that wire to activate the LP for filter priming-no need to remove the relay.

Your process is exactly right for pre 96 though except the relay is found on the firewall on the passenger side,although that can also be circumvented by applying 12v power to the ALDL pin G under the dash to activate the LP for filter priming.

Another note is that you should be opening the water in fuel drain valve with the engine running- it is also a good test for LP operation then-if the truck stalls LP diagnosis is required.

 

Thanks for the added tips. The 99 is the only one i have worked on. Im glad someone else had some key points to share!

 

On my '96 all I have to do is leave the bleeder open on top of the filter and then turn key to the on position so the lift pump primes the system. after fuel comes out i close the bleeder and start the truck. Most easy way i can think of doing it.

 

You only get about a 3 second LP run that way and then you tend to make a mess.
If the LP is already running when you open the bleeder you are also in the best position to close the bleeder before fuel goes everywhere.

 

I just lay an old towel in the area to soak up fuel.

 

On OBD I trucks you can run a wire from a positive terminal on either battery the the G terminal on the ALDL port under the dash and that will power up the LP it is a good way to check wether or not the LP is functioning

 

Anyone have any tips on bleeding injector lines? I know to crack open the lines and crank but I'm trying to avoid having to take off the turbo (again) to get to the passenger side injectors. I'll never figure out why manufacturers never designed a primer on light duty diesels like are on the big trucks I've driven. Unless of course that's another ploy for the dealer mechanics.

 

Injectors are self bleeding.

I do however crack #1 injector loose until the engine starts to cut down on cranking time.

 

Fixed it! Had air in the IP. Injectors won't self bleed if there's air in the IP. Disconnected the return line and used a brake bleeder vacuum pump to suck out the air. Fired right up after that! Found that little trick on YouTube. Much later than sooner, figures.