Chevy and GMC Duramax Diesel Forum banner

1 - 20 of 25 Posts

·
Registered
Joined
·
38 Posts
Discussion Starter #1
I changed my fuel filter and I cannot get it primmed. There are no leaks, everything is tight. I broke the wires for the water sensor located on the bottom of the filter. Would this prevent fuel to be pumped up to the filter?
Please give me some help very frustrated.:help
 

·
Premium Member
Joined
·
1,666 Posts
The wires should have nothing to do w/ priming, but they do need to be replaced. Priming can take a lot of pumps sometimes, or there may be a crack in the filter housing? You can also take the filter back off and fill w/ diesel fuel to help the priming issue, but if there is something else wrong, this will not help much!
 

·
Registered
Joined
·
641 Posts
Did you remove the bleeder screw or loosen it ??. while you were trying to Prime.
 

·
Banned
Joined
·
1,104 Posts
Like ICULKIN stated, make sure the bleeder screw is loose and pump it until diesel comes out. Then tighten it and continue to pump until it's rock hard. I always fill the filter 3/4 full with seafoam and priming is never an issue.
 

·
yep yep...
Joined
·
7,169 Posts
you don't need the wires for the WIF sensor, waste of money to replace i tore mine off 40K+ miles ago
 

·
Registered
Joined
·
38 Posts
Discussion Starter #6
I have filled the filter, loosened the screw and pumped until I cant pump any more. Still nothing. I have cranked the motor over hoping to push some fuel up to the filter to no avail. Any more ideas?
 

·
Registered
Joined
·
528 Posts
I have filled the filter, loosened the screw and pumped until I cant pump any more. Still nothing. I have cranked the motor over hoping to push some fuel up to the filter to no avail. Any more ideas?

EASY WAY TO GET IT PRIMED
Stock trucks don't have a lift pump
Make sure the filter is somewhat full and all seals are on, sometimes the center seal at the threads will stay on the housing, make sure that there is only one of these being used, you can use a small mirror to check this.
Lube seals with clean motor oil or diesel fuel ONLY.
crack the bleeder,
SLIGHTLY PRESSURIZE the tank with compressed air at the fuel filler using a blowgun and rags until you have fuel at the bleeder.
(Remember, the fuel tank is plastic)
Close the bleeder, clean surrounding areas with brake cleaner. Start motor, will proably run rough for awhile.
Check filter for leaks.
I use this method every time I change the filter.
This should take no more than 3 minutes or so.

You can crank for days and it will not self prime.
Good Luck, let us know when you get it going.
 

·
Registered
Joined
·
38 Posts
Discussion Starter #8
Thanks I will give it a try. I guess the rags are used to fill around the air nozzle to allow it to build up pressure. Can you put too much pressure to it?
 

·
Registered
Joined
·
528 Posts
Thanks I will give it a try. I guess the rags are used to fill around the air nozzle to allow it to build up pressure. Can you put too much pressure to it?

Rags are used to seal around the nozzle.
Yes, you can put too much pressure, hence the hint about the tank being plastic.
All you need is enough pressure to coax the fuel to a higher point. I would guess no more than say 5-8 psi and that might be high.
You are not trying to blow the line out, just moving fuel gradually that has gravitated back down the line.
If in doubt, err on the side of caution and start with lower pressure.
 

·
Registered
Joined
·
38 Posts
Discussion Starter #10
Well I tried the air and I did not have much luck. After I put air to it I then went up and started to pump it. Fuel would spit out but not in a stream. Is it possible that this would get it started? Before I changed the filter I started the truck let it run and it died in about 5 to 10 seconds. So I changed the filter and it hasn't ran since. Could the injectors be empty?
 

·
Registered
Joined
·
528 Posts
Well I tried the air and I did not have much luck. After I put air to it I then went up and started to pump it. Fuel would spit out but not in a stream. Is it possible that this would get it started? Before I changed the filter I started the truck let it run and it died in about 5 to 10 seconds. So I changed the filter and it hasn't ran since. Could the injectors be empty?
If fuel just spits out, you still have air in the line. Pressurize until you get a steady stream.
Once you pressurize to the bleeder with no air coming out, close the bleeder and DON'T use the manual pump. They can develope air leaks, that is why I prefer to use the pressurization method. Once you get fuel to the bleeder, close the bleeder.
Crank on it a few times.....should start. It may run rough for awhile until all the air is out. Once the engine is running, it is a self bleeding system by way of the return line.

If you crank and crank for awhile and it still won't run , pressurize to the bleeder screw, then tighten the screw.
Now, there is another fuel bleeder down line past the filter, located just to the left of the alternator (black cap ). Unscrew the cap and with the aid of a helper, pressurize the tank again and depress the schrader type valve inside the fitting untill you get steady fuel coming out with no air. Replace the cap and start motor.
May take a few cranks.
If it doesn't start doing this, I would go back to square one.
Check that the filter seals are correctly in place.
There is one "O" ring on the outer perimeter of the filter and one thicker seal at the center thread, plus the thicker "O" ring on the bottom for the water sensor. By the way, the water sensor is no more than hand tight. You can crack the sensor by using a wrench on it.
Let me know how you come out, I'll monitor this in case you have trouble.
 

·
Registered
Joined
·
38 Posts
Discussion Starter #12
If fuel just spits out, you still have air in the line. Pressurize until you get a steady stream.
Once you pressurize to the bleeder with no air coming out, close the bleeder and DON'T use the manual pump. They can develope air leaks, that is why I prefer to use the pressurization method. Once you get fuel to the bleeder, close the bleeder.
Crank on it a few times.....should start. It may run rough for awhile until all the air is out. Once the engine is running, it is a self bleeding system by way of the return line.

If you crank and crank for awhile and it still won't run , pressurize to the bleeder screw, then tighten the screw.
Now, there is another fuel bleeder down line past the filter, located just to the left of the alternator (black cap ). Unscrew the cap and with the aid of a helper, pressurize the tank again and depress the schrader type valve inside the fitting untill you get steady fuel coming out with no air. Replace the cap and start motor.
May take a few cranks.
If it doesn't start doing this, I would go back to square one.
Check that the filter seals are correctly in place.
There is one "O" ring on the outer perimeter of the filter and one thicker seal at the center thread, plus the thicker "O" ring on the bottom for the water sensor. By the way, the water sensor is no more than hand tight. You can crack the sensor by using a wrench on it.
Let me know how you come out, I'll monitor this in case you have trouble.
Thanks, that may be where I am messing up. I presurize the tank then crank the pump, I wont do that anymore. I also opened a thread up in 911 HELP! So check out my last post and see what you think. I will check the other bleeder. I was talking to the main man at the KY Farm Machinary Show in Louisville about two weeks ago he had a hand in making the duramax motor a reality. He said that the second line-it is steel or aluminum and holds about 23000 psi. Is this the second bleeder you were talking about?
 

·
Registered
Joined
·
528 Posts
Thanks, that may be where I am messing up. I presurize the tank then crank the pump, I wont do that anymore. I also opened a thread up in 911 HELP! So check out my last post and see what you think. I will check the other bleeder. I was talking to the main man at the KY Farm Machinary Show in Louisville about two weeks ago he had a hand in making the duramax motor a reality. He said that the second line-it is steel or aluminum and holds about 23000 psi. Is this the second bleeder you were talking about?
Second bleeder is low pressure just before the CP3 pump.
High pressure line is not aluminum, but cad plated steel, some aftermarket are stainless.
From the CP3 to the fuel rail and down to the injectors is high pressure, don't ever mess with the high pressure lines when the engine is running. It can inject fuel under your skin and into the blood stream.
The "O" ring kit you get from the dmax store is probably a better deal. The "O" ring for the plunger pump is very thin and when pumped dry, looses the seal allowing air.
A word of caution, when replacing the seal on the plunger DON'T crank down on the 3 torx head crews holding the stainless ring on the plunger, they strip real easy.
You didn't mention the temp before, add some Power Service in the white bottle to your fuel, it is an anti-gel. Get it at Wal-mart.
 

·
Registered
Joined
·
38 Posts
Discussion Starter #14
Yes I put the Power Service in the fuel at the last fill up, since then I have driven around 200 to 300 miles then it just stopped. There is a good chance that there is something else going on with the truck. But right now I just cant get it primmed. But I think I have learned a trick to getting it primmed. If I have then I will repost to let everyone know.
 

·
Registered
Joined
·
528 Posts
Yes I put the Power Service in the fuel at the last fill up, since then I have driven around 200 to 300 miles then it just stopped. There is a good chance that there is something else going on with the truck. But right now I just cant get it primmed. But I think I have learned a trick to getting it primmed. If I have then I will repost to let everyone know.

There is a problem on certain LB7 trucks where the fuel line has rubbed and created a slight pin hole in the line. May want to check this as well.
 

·
Registered
Joined
·
124 Posts
sorry to thread hijack but the bleeder valve on the bottom of the filter i broke the wires to it will that effect running or just throw a water in fuel code or just not throw any code at all no matter what since its not getting any feed back from it
 

·
Registered
Joined
·
528 Posts
sorry to thread hijack but the bleeder valve on the bottom of the filter i broke the wires to it will that effect running or just throw a water in fuel code or just not throw any code at all no matter what since its not getting any feed back from it
Wires going to the WIF sensor should not affect it, only effect might be the light on the dash would indicate water in fuel if the wires make continuity. Would not let it go too long, juist takes one bad fuel stop to give you a load of water......been there done that.
WIF puts certain model Fords in limp mode.
 

·
Registered
Joined
·
124 Posts
ooo ok well the wires snapped off right at the tip soo i guess ill have to buy a new one or something thanks
 
1 - 20 of 25 Posts
Top