Bad CDR symptoms?

[Mike82ndABN]

I have noticed that I get a little oily fluid under my truck, which I have traced back up to the air cleaner dump valve, and confirmed a little of it inside the air cleaner housing.

The fluid isn't ATF (thankfully), it is a clear-ish brown fluid. I had been thinking that it could be power steering or brake fluid from a vent line (not sure if this happens with the vampire).

I was researching valve cover leaks and came across some info about the CDR allowing excessive pressure if it goes bad (stuck closed), and one of the symptoms of a bad CDR (stuck open) was finding engine oil deposited in the intake and air cleaner from the fine mist.

I am beginning to think this fluid may be engine oil, I only get a few drops here and there so it is hard to figure out what exactly it is but it is oily and it is not red.

Does anyone have an input? Thanks. I may change it out as preventative maintenance.

 

[Retiredwarhorses]

Unless it's a fording CDR, no way for fluid to get there. Brakes aren't vented to anything.
Ps is ATF...but again, unless you have a fording cap on the PS..no way.
change the CDR out...

 

[Retiredwarhorses]

Let m e add...army trucks don't have fording kits...

 

[Mike82ndABN]

So I disconnected the skinny vent line going to the top of the air cleaner and ran it towards the cab, so that I could observe it through the doghouse opening. While driving I saw spurts of diesel shooting out the vent line. This is not the thick vent line with the check valve, this is the skinny one that goes the elbow on the top of the air cleaner.

I disconnected a T between above the transmission and diesel came out.

Research says this could be a bad diaphragm in the lift pump? That's the only place diesel components are connected to the vent system correct?

pic of T that I disconnected....

 

[Retiredwarhorses]

Your fuel pump diaphragm is bad, the vent on the pump goes to your hubs, diffs,trans and tcase and terminated in the air filter...the one behind the coolant bottle is a fuel tank vent, it's not part of the above...I would replace your fuel pump.

 

[Stonepicker1]

This happened to a few of our HMMWV's in Iraq. Bad Lift Pump. Time to drain the hubs and transfer case.

 

[86humv]

I have new ones available.

 

[Mike82ndABN]

I found one locally and was going to install tonight. I'm under the impression that I will have to crank it over quite a bit to get fuel flow to the injector pump again after replacing the lift pump, will that harm the glow plugs (just replaced). Should I disconnect the glow plugs during all that cranking or will that harm the Smart start box.

 

[Retiredwarhorses]

Truck should just start and run with no issues...I change them all the time.
they aren't easy though....that arm needs to be set correctly on the shaft, so you may need to remove the plate as well.
take the rod out and load it up with grease to hold it in the up position...if done wrong the rod won't push the arm on the
pump and no fuel will flow...I install the plate, then out of luck, keep the rod in the up position and insert the arm in in one fell swoop...have fun.

 

[Mike82ndABN]

Changed it out. That went well. Thanks.

The rod was stuck down, so I did end up removing the plate. Greased rod and it held until I replaced the plate and pump. Auto parts store had the plate gasket. I think it was part 5182 (or something like that) I cross referenced with an 89 blazer. I would advise anyone to pick up that gasket to save a second trip later lol.

Very little torque needed on those 4 bolts.

Thanks

and you were right. Started up on the first crank. Smoothed out after a minute.

 

[Mike82ndABN]

Changed out all the fluids a couple days ago.

All 4 hubs gushed when I removed the fill plug, definitely contaminated and overfilled with diesel, gear oil looked thin when I removed the drain plug.

Differentials also had extra fluid when i removed the fill plug.

Transfer case was good.

I must have drained just over 7 quarts from the transmission, if I measured correctly, so diesel must have made it's way there too through the vent line when the diaphragm in the lift pump leaked.