Ford 6.8L V10 Vacuum Line Diagram
Ford 6.8L V10 Vacuum Line Diagram
I think I found the source of my engine troubles.
Here you can see it sticking right out in plain view in the open, I feel really stupid for not seeing this. The way the smaller hose wraps in a coil should have given it away too.

Here you can see where it leaves the intake manifold and where it is literally just sitting in the hose adapter.

After pulling the heater hose off, and the PCV valve, inspecting the smaller hose that connected them shows that its not one hose but two joined by a small threaded pipe, like you would find inside a table lamp!!!!

Here is the partially repaired view, I used a 5/8" Elbow at AutoZone marked "Ford PCV", the 1/4" to 5/8" and a 10" section of new fuel hose.

Here is the emissions control label on the hood.


The diagram clearly shows the line coming from the intake and then splitting into two, one going to "Main Vac", and the other to a "FPRC", which is related to the Fuel Pressure Regulator.
The PCV valve is labeled to be connected to "Main Vac", but not shown where on the diagram.
I have the vacuum line from front of intake to the PCV valve with not other connections. Which according to the diagram is wrong.
Should I have replaced the PCV valved? Do they go bad?
Also a big thanks to everyone here for their ideas and suggestions.
Here you can see it sticking right out in plain view in the open, I feel really stupid for not seeing this. The way the smaller hose wraps in a coil should have given it away too.

Here you can see where it leaves the intake manifold and where it is literally just sitting in the hose adapter.

After pulling the heater hose off, and the PCV valve, inspecting the smaller hose that connected them shows that its not one hose but two joined by a small threaded pipe, like you would find inside a table lamp!!!!

Here is the partially repaired view, I used a 5/8" Elbow at AutoZone marked "Ford PCV", the 1/4" to 5/8" and a 10" section of new fuel hose.

Here is the emissions control label on the hood.


The diagram clearly shows the line coming from the intake and then splitting into two, one going to "Main Vac", and the other to a "FPRC", which is related to the Fuel Pressure Regulator.
The PCV valve is labeled to be connected to "Main Vac", but not shown where on the diagram.
I have the vacuum line from front of intake to the PCV valve with not other connections. Which according to the diagram is wrong.
Should I have replaced the PCV valved? Do they go bad?
Also a big thanks to everyone here for their ideas and suggestions.
I have a 2006 F550 chassis V10 gas underneath a 31' RV.
When I turn ignition on Run I hear a very quiet pump run constantly but can't find where it is! Don't have front drive, So the leak must be in lines at or in the tank, or to the AC Heater Control panel???
That dashboard is a beast to get off to check its hose connector.
I'm thinking might be wise to get new pump, tank & hoses and be certain I'll not get off camping and lose heater & aircon for a very long tough drive up and over the mountains.
15# vacuum pump, what size hose? Isnt there a valve, too or is that in the tank?
Any suggestions?
THANKS AGAIN
bobcleve07@gmail.com
Last edited by Bob Cleveland; May 22, 2024 at 05:02 AM.
Thread
Thread Starter
Forum
Replies
Last Post
jakeharp
1973 - 1979 F-100 & Larger F-Series Trucks
2
Nov 28, 2016 12:36 PM
edmondsonk
Explorer, Sport Trac, Mountaineer & Aviator
1
May 10, 2008 04:47 PM









