LB7: Coolant leak....

[whitetrash21]

Had this problem for a few weeks. Truck uses about a gallon a week. Thought it might be an injector cup, but these pics says something else. Just saw all the fluid, have never seen it there before. I dont know if I missed it before or if it just started. Doesn't look like a surge tank lid to me as the tank top is clean... no dex stains there.

The first 6 pics are of the spray I can see on the motor and accesories. Drivers side is clean. Could this be the egr cooler doing this??? Heater core line??? Doesn't drip anything on the ground when i park it, but there definately is fluid sitting in there. Seems to me it's only leaking when I'm actually driving around, since if it leaked at idle , there'd be a puddle somewhere..... Not to mention that at idle, I cant see fluid coming from anywhere.

The last two pics I have no idea what that is. It's plumbed into the intake, and when I started the truck, it was moving in the direction the arrows show. It only did this for about 45 seconds or so and then stopped. It was suggested it be the egr opening and closing to help heat intake air up, thus warming truck?? Thoughts??

I hate emissions controls.....

Anyway, thanks for any help.

 

[bullfrogjohnson]

have you put a bottle on the coolant tank line and driven it? It definatelt looks like you have some pressure behind that leak

 

[whitetrash21]

Which line??? It looks to me like it's either pressure or else it only leaks when i'm actually driving it and the fan or wind is blowing the coolant all over the place....

Something like that

 

[bullfrogjohnson]

Follow the overflow tank cap and there is a rubbe line that comes off and goes down the side of the tank and dumps off excess pressure. Put that line in a bottle and drive around. This will eliminate you pressurizing the collant system.

 

[whitetrash21]

Roger. thanks. Try that tomorrow.

 

[Jared Duramax]

take a look at your hard line that attatches to the motor from one of the heater core lines above the passanger side manifold i have seen these crack where they have the mount welded on them and cause leaks.

if you do find out you are getting coolant out of your overflow tube based on using a bottle let me know as i have just gone through all of this and feel confident about the cooling systems on an LB7

 

[whitetrash21]

~60 miles today. No fluid in the bottle. I'll keep driving it, see if anything shows up.

 

[Jared Duramax]

~60 miles today. No fluid in the bottle. I'll keep driving it, see if anything shows up.

how hard did you drive the truck during those miles?

 

[whitetrash21]

I only have one way of driving... and that's drive the piss out of it. If something is gonna fail and not show, it WON'T be because I'm babying it.

 

[TrentNell]

take a look at your hard line that attatches to the motor from one of the heater core lines above the passanger side manifold i have seen these crack where they have the mount welded on them and cause leaks.

if you do find out you are getting coolant out of your overflow tube based on using a bottle let me know as i have just gone through all of this and feel confident about the cooling systems on an LB7

x2 i bypassed the hard line and am now using soft line cause it will crack again if you replace it. my truck did the same thing and then one day it started leaking really bad.

 

[whitetrash21]

Forgot to look at that today when plumbing the bottle. I'll check it tommorow. Thanks for the help guys.

 

[sweetdiesel]

~60 miles today. No fluid in the bottle. I'll keep driving it, see if anything shows up.

thats good and a good test IMO I have a bottle that is used as a overflow constanlty on my one truck just incase it decides to blow coolant on my tires

You could try to pressure up the coolant tank to like 13 psi and let it sit over night and see what the pressure is in the morning if its down you could also pull glowplugs and fuse and then crank it over in the moring to see iff it blows coolant.

or have a real close look at all the coolant lines and water pump

Does it burn white at first start up?

 

[LBZ]

I only have one way of driving... and that's drive the piss out of it. If something is gonna fail and not show, it WON'T be because I'm babying it.

Sounds like what Kurt said one time "If it ain't coming out of the driveway sideways with smoke rolling off the tires then it ain't me driving":rofl:

 

[Jared Duramax]

That kind of sounds like me my truck has never had an easy day of driving:angel::driving:

 

[whitetrash21]

thats good and a good test IMO I have a bottle that is used as a overflow constanlty on my one truck just incase it decides to blow coolant on my tires

You could try to pressure up the coolant tank to like 13 psi and let it sit over night and see what the pressure is in the morning if its down you could also pull glowplugs and fuse and then crank it over in the moring to see iff it blows coolant.

or have a real close look at all the coolant lines and water pump

Does it burn white at first start up?

No white smoke at all, even at a cold start. Temps been getting to ~50* here at night and when I start it in the morning, it sounds like an old 12v cummins... Still no white smoke and timing rattle goes away after about a minute of driving.

I checked anyplace coolant lines run on the front and drivers side... no leaks. I just replaced the pump about 15k miles ago. Pass side lines are all coated in Dex, but i cant tell where its coming from. Wipe it down, sdrive it and its all back

 

[whitetrash21]

take a look at your hard line that attatches to the motor from one of the heater core lines above the passanger side manifold i have seen these crack where they have the mount welded on them and cause leaks.

Not quite sure which lines you are talking about. The two lines in Picture 3 are the heater core lines I'm seeing. One of them goes from the radiator directly to the firewall (the left one). The other does a loop and goes into what I'm seeing is the egr cooler (picture 1) ..... No signs of fluid leaking from any of the hose clamps/hose/hardpoints on any that I can see.

Got about 100 miles on total, still no fluid in the bottle.

 

[sweetdiesel]

So the coolant that you are seeing is beig blown from the fan while driving I take it

Wes have you tried just pressuring the system and wiping off the hoses first

I think if you have a external leak that is probably a good thing as compared to internal leak

 

[whitetrash21]

So the coolant that you are seeing is beig blown from the fan while driving I take it

Wes have you tried just pressuring the system and wiping off the hoses first

I think if you have a external leak that is probably a good thing as compared to internal leak

Thats what I'm assuming.... Cant tell for sure though.

Haven't tried pressuring the system yet. What would I use to do that??? I have wiped the hoses down. Drove it right after that, flkuid all over them again. Can't tell where it's coming from since I cant see any leaks when it's idling.

You're right about the leak being external, just hope it's not a HG. I kinda doubt it would be as the fluid probably wouldn't be so high up on the motor. Seems to me a HG would be pushing fluid down the block or into the motor.

~200 miles now, still no fluid in the bottle.

 

[Jared Duramax]

in your first picture you show the line going to the radiator this is the one i am talking about.

follow this line till it becomes an aluminum line that bolts to the motor

now where it bolts to the moter at there is a mounting bracket that is tig welded to the pipe

at the weld is where i have seen these leak at check this spot but you really need to pressurize the system in order to locate the problem because the fan really blows the coolant around

 

[whitetrash21]

in your first picture you show the line going to the radiator this is the one i am talking about.

follow this line till it becomes an aluminum line that bolts to the motor

now where it bolts to the moter at there is a mounting bracket that is tig welded to the pipe

at the weld is where i have seen these leak at check this spot but you really need to pressurize the system in order to locate the problem because the fan really blows the coolant around

Gotcha. I'll check that out in a bit.
Where can I get the stuff to pressurize the cooling system?? Whats a safe pressure to hold it at???