Forum newb here and a search did not yield the exact results I was looking for but I believe I am on the right track due to them. I am working on my parents 98 Dodge Ram 1500 with 5.9. I am in the process of doing a rear main seal replacement and also trying to find a coolant leak. I pressurized the system with my tester after and left it for a few days and it gradually dropped from 15psi to around5 psi after 3 days. I went under the truck to see what I could find and I found coolant in the bell housing (I had already removed the trans inspection cover working my way towards the seal repair. The coolant was not there when I first removed the inspection cover. I had looked in there to verify I did not have a front trans seal leak. I noticed when I removed the oil pan that I had some coolant that appeared to run down the passenger side oil pan bolting surface and seems like it all came from the front as I could see tiny traces of coolant all the way up to the front and coming from the top corner of the passenger side bolting surface.

The engine is sitting at a 7 degree angle with the front being the high side. I have the front jacked up pretty high to allow me plenty of room underneath. I am speculating the coolant that is in the bell housing is actually a leaking front cover gasket and has slowly worked its way from the front down and back.

The freeze plugs that I could see do not appear to be leaking and feeling the ones behind the motor mounts appear ok too. I do not suspect the ones in the rear behind the bell housing because I never had coolant there until I pressurized the system with the front of the truck sitting up. The leak being so slow is making this a challenge and I do not have dye or a light to go that route.

Hoping for some insight before I tear the front end apart because if I am going to do the front cover I am going to do the timing chain, etc.

 

So what exactly is your question? Common leaking areas include: tstat housing, heater tube, water pump, hoses, radiator and heater core. Once you find it, sounds like you'll be fine in fixing it.

 

I'm from over in 2nd gen vans so you don't have to listen to me but I had a similar slow leak coming from the front. Could occasionally see the trace of it coming down the side of the timing cover and edge of the front of the oil pan, passenger side, but never made it to the ground. I'd take a look to see if there's any pooling around the thermostat housing- hose clamp not quite holding the pressure, and also the bypass hose area. In vans it's tough to see that area but you should have a decent view looking down there with light.
This was a problem before and after replacing the thermostat, one day I had shined a light through a small space between the alternator and bracket and found the pooling that had been happening. I had tightened the clamp well on install but after a while it seemed to have expanded n loosened slightly, the fix for me was double clamp the hose on the thermostat housing

 

My question is, is it possible for this chain of events to happen, where the coolant is leaking from the front and coming back into the bell housing following the oil pan mounting surface and be plausible or am I just being hopeful to avoid dropping the trans in order to do the rear freeze plugs and I actually have two leaks?

Also good info on the common leak points, I will look more in depth into those areas when I get back out to it in a couple days.

 

I've had a couple leaks: heater tube at pump and tstat housing. Both dribbled down the engine and disappeared. Never made it to the rear of the engine. I'd say you have a leak in the rear somewhere. One leak was bad enough to be seen on the cross member in front. Not sure how it could get so far back unless the heater hose/ core connection is rotted at the firewall. I'd suspect freeze plugs as a last resort. Check the heater hoses as they route around back.

 

I'm painting my engine and found somewhere I had a couldn' leak they never hit the ground. On the bright side my truck has a way to constantly cost the crossmember so it will never rust when got the inside

 

Lol, yeah between my leaking steering pump and various coolant and seal leaks, my truck frame is rust proofed!!

 

Got to love Dodge and their innovation, I need what other car company includes a self rust proofing? None.