Strange problem.

[swindad2]

Okay, first off let me say, this will probably sound dumb to the pros on here, but I am confused. I am new to the deuces and still learning. So I noticed after driving the truck and shutting the engine off, you can hear what sounds like the oil draining and dripping back into the oil pan. I haven't given it much thought till today.

I have been slowly losing brake fluid. I found a loose line on the air pack a couple weeks ago and tightened it, but I am still losing fluid. Okay no big deal I will trace the lines and check the wheel cylinders again. I climbed up under the truck just after shutting her down today and went back to the air pack. I could hear what sounded like dripping inside the master cylinder, but the dripping in the oil pan was so loud I couldn't tell. I climbed back out and drained the air from the tanks, and then, total silence, no dripping sounds, not even from the engine. So I thought, okay that has to be a coincidence. I cranked her back up let the air pressure build, and same thing: loud dripping noises in the engine. Let the air back out of the tanks, and silence again. What the heck? Surely the air pressure has no influence on the engine. What are your thoughts?

 

[porkysplace]

Hopefully you plan on parking the truck until the brake fluid leak is fixed. The leak may be in the air-pac / master cylinder with the sounds you describe .

 

[welldigger]

The dripping sound you hear is oil flowing back to the oil pan. Completely normal. Check the vent tube under the hood near the air cleaner and firewall. If brake fluid is present then your airpak is bad. Though this test doesn't mean it isn't leaking internally.

 

[NDT]

Define "slowly losing fluid". The MC only holds, what about a pint? Any kind of rapid dripping would run you dry in no time.

 

[swindad2]

I have the remote mount reservoir kit from Real Custom Trucks installed. It leaked down about half a tank over night with no air pressure. I guess what was confusing was the sound I was hearing. I steady drip, drip, drip. But it was a more metallic sounding, almost, ping, ping, ping. Only seems to occur with air pressure on the lines. But is sounds like its coming from the front around the oil pan, so I assumed it was oil dripping back (it shouldn't be that loud). Of course, with an old truck, there are plenty of oily parts under there, so hard to tell in some places.

I guess she will be sitting a while. Was hoping the old girl would hold together till spring. The plan was to get my motorcycle sold so I could do a full axle service and go through the brakes: (just replaced the air pack) master cylinder, wheel cylinders, rubber hoses, boots, seals, etc. And a set of G177's. I thought I had the leak fixed, but I just drove it down the street and parked it in front of my shop today, for Veterans Day.

 

[welldigger]

If there are no visible leaks then it pretty much narrows it down to either the airpak or a wheel cylinder. It wouldn't hurt to check the master cylinder while your at it. Really easy to check the MC. Just pull the rubber boot back from the MC and if theres brake fluid behind it then its bad. If its dry then you can rule it out.

 

[swindad2]

If my master cylinder is working correctly, would the fluid all drain out of it while sitting overnight?