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EBV OIL LEAK TSB 04-20-2 PRELOAD

11K views 31 replies 10 participants last post by  69mach1377 
#1 ·
Many 7.3s leak from the turbo charger pedestal.
Many that live in warm climates purchase a pedestal that does not have the exhaust back pressure valve. The factory manual states that it's purpose is to warm the cab faster. It closes the turbo charger's outlet with a butterfly flap restricting exhaust flow. This makes the engine heat up faster than without the feature.
Getting cold oil warm is key to helping reduce wear. In addition the truck will run better sooner.
Ford issued service bulletin TSB 04-20-2.
You remove the intercooler pipes and compressor manifold (y)
Remove turbo and pedestal.
Remove circlip and plug from back of pedestal.
Remove three pipe plugs from pedestal
Attach flex brake cylinder hone to drill.
Clean out cylinder and inspect. The bulletin says to clean and install seal kit assembly.
There is a vendor that says to not hone the cylinder. Being a diesel and hydraulic mechanic dealing with countless cylinders I can say that if the walls of your cylinder are shiny you have a slim chance of the new seal kit lasting very long if the truck will be in an environment with temps that activate that valve with any level of frequency.
The seal that acts as the back of ram only travels a short distance in the cylinder back and forth wearing the wall leaving it shiny and with irregularities.
A new seal is perfectly round and will not seal well against walls in that condition.
Now the bulletin wants ten pounds of pressure preloaded on to the seal/ram assembly. The reason for this is that the cylinder does not act as a centering device for ram. With no load on it it is free to tilt up down or side to side uncentering and un stabilizing the seal arrangement causing the leak.
So we have to put ten pounds of preload changing the seals traveling path and sealing surfaces.
Hone the cylinder with flex hone on slow speed with a medium speed in and out to create cross hatching marks that are at about a 30 degree pattern.
DO NOT take anything but the shining glaze off.
There are oil passages in the front of cylinder and very front against wall.
Pay extreme attention to getting that cylinder and passages clean.
 

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#30 ·
i thought the ebpv wasnt supposed to activate while your driving? i thought it only came on at idle. just curious
 
#32 ·
It sure does activate while driving and it's very noticeable.. Tapping the brake releases it IIRC.
 
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