Head gaskets?

qcfarmer · Feb 18, 2013

Truck puked on me for the first time today. How do I test if its gaskets or just the cap? Thanks

fnlyfree · Feb 18, 2013

You can borrow a block leak detector from a local auto parts store and use that. You can also attach a pressure guage to the degas bottle and drive the truck when it is cold. If pressure builds quickly and shoots to 16 psi (cap relieves at 16) you probably have a leaking gasket. You shouldn't see much more than 5-6 psi in the degas bottle.

It is possible for a leaking egr cooler to cause the truck to puke. The water leaked from the cooler can flash to steam and over pressure the system. Moisture inside the egr valve would be a good indication of a cooler leak.

Is your truck smoking?

qcfarmer · Feb 18, 2013

No smoke, also egr coolers are gone. It puked while I was towing my cattle trailer this morning (around 10000 lbs) even though boost never went over 30 psi. I then hooked to a load of hay (20000 lbs) and hit 30-32 psi a few times and it didn't puke.

tensixniner · Feb 18, 2013

What tune are you running?

It's almost not worth testing a cap. A new one is like $12.

B585Ford · Feb 18, 2013

fnlyfree said:
You can borrow a block leak detector from a local auto parts store and use that. You can also attach a pressure guage to the degas bottle and drive the truck when it is cold. If pressure builds quickly and shoots to 16 psi (cap relieves at 16) you probably have a leaking gasket. You shouldn't see much more than 5-6 psi in the degas bottle.

It is possible for a leaking egr cooler to cause the truck to puke. The water leaked from the cooler can flash to steam and over pressure the system. Moisture inside the egr valve would be a good indication of a cooler leak.

Is your truck smoking?

Personally, I am a big fan of the pressure test at the degas...especially since you don't have the EGR. Without the EGR, if the coolant gets pressurized there's a 99% chance it is the HG. If you aren't familar with setting one up, make sure run the gauge into the truck so you can see what it is doing in real time. Of course, to be completely accurate, you have to get the truck to puke. On all the ones I have done with a mild leak (like yours), the gauge read 3-5 PSI when the truck was warm, but as soon as you punched it, it went to 16 immediately, then dropped a few (12 to 14 IIRC) after letting off and stayed in that pressure range for quite a while. Good luck.

zippyrat · Feb 18, 2013

pressure test at the degas, best test

fnlyfree · Feb 18, 2013

B585Ford said:
Personally, I am a big fan of the pressure test at the degas...especially since you don't have the EGR. Without the EGR, if the coolant gets pressurized there's a 99% chance it is the HG. If you aren't familar with setting one up, make sure run the gauge into the truck so you can see what it is doing in real time. Of course, to be completely accurate, you have to get the truck to puke. On all the ones I have done with a mild leak (like yours), the gauge read 3-5 PSI when the truck was warm, but as soon as you punched it, it went to 16 immediately, then dropped a few (12 to 14 IIRC) after letting off and stayed in that pressure range for quite a while. Good luck.

:whs: