Fuel Density Compensator

[Floridianson]

Nope the sticker is incorrect and no way of doing it internal. Seen that on a couple of trucks. Sorry got to get your hands dirty. The thing I have found is not all trucks are set the same. So some we have to turn down the fuel at the main and then adjust the droop after FDC bypass or you might be able to crank the main up some and then again adjust droop so as not to waist fuel till the turbo spools up more. If you have an IP with no droop then we have to do the smoke cam but you have to very watch full of what you are doing but it is not a big OMG problem. Do need a good pyro before doing the bypass if you want all you can get from the tweeking. Boost gage is also helpful but not a important.

 

[daytonatrbo]

Nope the sticker is incorrect and no way of doing it internal. Seen that on a couple of trucks. Sorry got to get your hands dirty. The thing I have found is not all trucks are set the same. So some we have to turn down the fuel at the main and then adjust the droop after FDC bypass or you might be able to crank the main up some and then again adjust droop so as not to waist fuel till the turbo spools up more. If you have an IP with no droop then we have to do the smoke cam but you have to very watch full of what you are doing but it is not a big OMG problem. Do need a good pyro before doing the bypass if you want all you can get from the tweeking. Boost gage is also helpful but not a important.

That's what I thought. I just replaced my fuel filters. Up next is oil and oil filters. Then I'll be doing the bypass because I think I'm starting to see some fuel in my oil.

I'll have to get some gages when money allows. For now, I'll just stay well out of the throttle. The truck doesn't see much use anyway.

 

[gimpyrobb]

That's what I thought. I just replaced my fuel filters. Up next is oil and oil filters. Then I'll be doing the bypass because I think I'm starting to see some fuel in my oil.

I'll have to get some gages when money allows. For now, I'll just stay well out of the throttle. The truck doesn't see much use anyway.

If its not plumbed like your 109, it isn't bypassed.

 

[daytonatrbo]

If its not plumbed like your 109, it isn't bypassed.

Yeah, the sticker must be lying.

 

[gimpyrobb]

Or a different can was swapped in.

The military way was to use that short piece on the FDC(from the "out" to the "in") and then run the fuel line from the filter to the IP, so that if ever needed, you could put the FDC back in the loop. I doubt I'll ever hook mine back up though...

 

[DawnandAlfie]

Thanks for the info. Perhaps you could confirm something else. I removed th FDC off my IP and the wedge finger that sits down into the IP pushed into the FDC with some resistance however when I tried this with the brand new FDC even using considerable force it would not move at all. We did fit the new FDC pump and the truck seems to be running ok but I'm a little worried. Another question, I had my M35A2 on a 50 mile trip left it sitting for 2 weeks and noticed a trickle of oil from the bottom of the back plate on the 3rd axle running onto the wheel rim and inside of the tyre, I cleaned it all down took it for a 4 mile run, parked it up and there is no leak there now. The vehicle had been standing almost 6 months before the 50 mile run and the oil is still up to the marker on the filler plug. Do these seals dry out then work well after they relubricate whilst driving ? (My Daimler Ferret was known to gave considerable oil leaks at each wheel station after standing for a month or so but after a few miles were travelled they would reveal and not leak, minor difference they were leather seals and EP 140W oil !) thanks in advance .

 

[FLYWHEEL]

Hi DawnandAlfie,
I would check that it is not brake fluid running down the back plate on your wheel, you can't be to careful with single circuit brakes.
Also there is a small vent on top of each axle check to see if they are clear and working. On a long trip the oil in the axles heats up, and if the vents are blocked it pressurizes the axle and can force oil pass the seals, on a 4 mile trip the axles probably won't get warm enough to pressurize the axle and force the oil out.
These trucks are fairly easy to maintain, if you use the search function on here you should find answers to all your questions. If you haven't downloaded the TM's yet, i would do so. This forum has a lot of good people on it with a wealth of knowledge to help you.

 

[gimpyrobb]

I can't comment on the FDC, mine are bypassed.

I agree its probably the vent is clogged and pressure pushing out the G.O.