fuel leak

[Suska]

My 1973 31 FC has a fuel leak. I had it serviced locally and they tightened the fuel pump where it connects to the block. This appears to have slowed the leak but not stopped it. I am thinking perhaps a gasket??? Any thoughts?
Thanks

[Bill Pape]

The injection pump and the 3208 engine block??? ,
Or a fuel pusher pump in the fuel line???

[Suska]

Originally Posted by Bill Pape

The injection pump and the 3208 engine block??? ,
Or a fuel pusher pump in the fuel line???

So here is where my lack of knowledge as a new owner begins! It is a 3208NA
and I am, thus far, only able to repeat what the mechanic told me

[Suska]

Originally Posted by Bill Pape

The injection pump and the 3208 engine block??? ,
Or a fuel pusher pump in the fuel line???

It is the injection pump/3208 engine block

[Bill Pape]

You will be an expert sooooooon..

Is the leak on top of the 3208 engine ???
Or under the bus along the fuel line that leads to the rear fuel tank???

[Suska]

I hope so!!!
The leak is on top of the engine, we can "mop" up fuel from the dog house.

[NH Bill]

I went through this drill last year with our 83 FC 3208T. Fuel was collecting in the valley from an undetermined source. Some suggested it could be the seal at the throttle shaft rod (lower left side of injector pump) apparently this is not uncommon. However, my leak(s) were from old hoses... I changed out all the hoses on the injector pump and that took care of it. One year and 3,500 miles later ... nice dry valley.

Hope this helps - Bill.

[Bill Pape]

The fuel collects under the injection pump at the bottom of the valley,
try to clean & dry it up, I use break cleaner or carb cleaner, This stuff is highly flammable needs lots of ventilation. Leaks could be coming from several hoses. The lines leading to the injectors for each cylinder can crack & leak.
tighten each injector fitting with a 3/4" open end wrench.
And yes the throttle rod has a high incidence of leakage.
After cleaning and drying up the mess, check for fuel weeping around the throttle, cable, springs.
First, Ya need to be a detective..... then a mechanic

[Suska]

Originally Posted by NH Bill

I went through this drill last year with our 83 FC 3208T. Fuel was collecting in the valley from an undetermined source. Some suggested it could be the seal at the throttle shaft rod (lower left side of injector pump) apparently this is not uncommon. However, my leak(s) were from old hoses... I changed out all the hoses on the injector pump and that took care of it. One year and 3,500 miles later ... nice dry valley.

Hope this helps - Bill.

Thanks Bill,
It is good to know all of the possibles, we will take a look @ the seal and the hoses! Glad that you found a solution.

[giderich]

The 'Fuel in the Valley' probably is caused by leaking O rings at the base of the governor housing which bolts to the rear of the injection pump, and/or the throttle shaft seal. Some shops my want to install a remanufactured injection pump. Your call...may not be much more labor. Parts will be readily available by going to the CAT dealer with 3208 engine serial No and the arrangement No. If you have time ask around for an 'older' truck mechanic who is familiar with the older 3208 engine. Pretty straight forward job for any truck shop.