#5.9 CUMMINS REAR MAIN SEAL LEAK SIGNS DRIVER#

The smaller bolts were barely finger tight.Engine gasket oil leak. One method to track down the damaged injector on a common rail 5.9L Cummins is a simple visual test. Wipe it in the evening and the row of drips would be back the next morning. Specially attractive when the pipe heated up. The hose on my crankcase air breather filter is so soft, it might not take too much vacuum to collapse it so I need to change that out too.Īs for oil leaks, before I tightened the valve cover bolts, the exhaust pipe running under the back of the motor had a steady line of drips on it. According to the Haynes book, the V8 breather filter can be cleaned and reused unless the filter material has broken down. On my 6, the filter material appeared to have not been changed since God was in diapers. It seems like people either have no issues. Outside of these two issues the 5.9 is generally a stout and reliable engine. What I read is that if these filters clog they can exacerbate oil leaks. The two biggest issues with the 5.9 Magnum are plenum gasket leaks and the weak cylinder heads. On the V8, it is apparently a metal housing on the oil filler. On the 6, it is a plastic housing inside the can housing the air filter. The V8 and the straight 6 both have air filters on the breathers for the PCV valves. check the other side.Īlso sometimes the leak can originate from the valve cover gasket Post edit: the dab of silicone could be a bit lean at the junction of the seal and the engine block. Is your crankshaft steady, no fore and aft motion when pulling/pushing on the harmonic balancer? Also the block edge is really sharp, once while pushing the seal the razor end of the block shaved a bit of the new seal (hence why I do get 2 seals) Pre Warm the seal to soften its texture ,obviously it is summer now, but if you live in Alaska or San Francisco, it is good to warm up the seal Loosen crankshaft caps as listed in the TSM.Īnd yes it is a pain to push the upper seal, last time after I pushed the first 1/4 inch off, I used one of the new seal to push the old one (hence why I get 2 seals) you can pre-oil lightly the seal to ease the extraction, the TSM says soap. Now that everything is out of the way, you may as well do it and buy 2 sets of rear main oil seal. you oil pan gasket looks almost non oily so that may not be your case. I'll take a stab at it: you are correct that it is not obvious, it can be as simple as a loose oil pan bolts. If you saw my Jeep leaking youd crap yourself its that bad lol. I think your leak is from the oil pan itself. But that damn pipe kept me from using a punch or any kind of tool to get the upper seal out. They sell replacement L shaped pipes at the autozones and stuff and i can weld so it wont be a big deal. I think when i attemot to do my rear main ill cut the exhaust off with a reciprocating saw where it bends into that L shape. It helps to jack the vehicle up really high and let the axle drop down. But i cant remember off my headĪnd yea the pan is a pita to get off. I think its around 50-60 ft lbs for them. Just make sure you oil it when you put the caps back on. But im sure i have some camshaft issies as i hear lifter noise when the engine is cold.īut at least i know the bottom end is good from what i could see.

The piston skirts looked good and the cylinder walls looked good. These seals must be installed absolutely straight or they WILL leak. OEM Rear Main Crankshaft Oil Seal kit 3925529 for Cummins 5.9L 12V 24V Engine. My rod bearings looked brand new still had almost no wear with 120k miles when i did it. THIS AD IS FOR A NEW CUMMINS FRONT SEAL USED ON 1989 AND UP 6B & 4B ENGINES. I took off the bearing caps for the rods snd looked at them and crank journals to see how the bearings and stuff were doing. And when you put the cap back on put some motor oil all over the bearing so it isnt dry and torque it to spec.

#5.9 CUMMINS REAR MAIN SEAL LEAK SIGNS DRIVER#

I know we had a driver It may have been a Home made one. Whatever you do dont touch with your nails or scratch the main bearing and dont scratch the crank once you have the cap off. I looked in my book to get the seal driver number, there is not one. Take that bearing cap off and youll see half of the seal on the cap and the other half is on top its the top one thats a pain to get off. That is the main bearing on the crank shaft right there. The rear main seal is two rubber gaskets you have to um bolt those two large bolts there. Ive heard these engines can wear a groove into the crank and even with a new seal itll leak. Sucks i lose a quart every like 300 miles lol. so i just did the lower seal and did jack squat. but i couldnt get the upper one out due to the exhaist pipe being in the way. and bend it into U shape to capture dripping oil to keep it off my exhaust. my rear main leaks so bad i had to add a thin sheet metal plate on the inspection cover. Wish i could help on where your leak is coming from.

5.9 cummins rear main seal leak signs