Hi, I'm a first time poster so I hope this was the right place to go.

I own a 99 Dodge Dakota SLT, 5.2L V8 Magnum, extended cab, 4x4 truck. It's green. Just a little back story, I put a new water pump in, on Superbowl morning in 2016 (this might help with my actual question later).

Couple weeks ago, I had a crack in the plastic of my radiator show up, so rather than limp it along, I went down to a LKQ outlet and ordered a new one and got new hoses (and clamps). I put it in and it worked like a charm. However, the next day, I noticed leaks again. So I checked all of my hoses, clamps, I mean everything. They were all fine. Since I had to work 70 hours the week before Christmas, I was forced into procrastinating on finding this issue for a week.

Ok, so today, I am running the motor up to running temp, then pushed the throttle and I saw coolant suddenly welling up and trickling down to the passenger side, just behind and top of the water pump, and over the lower water pump hose. Checked the thermostat out, seemed alright. Bone dry even (on top, dunno if can leak from the bottom). The trickle was under it, so I'm thinking, could it be the bypass hose, and nope, that seemed ok too. I checked the oil, and no white cake stuff was in it, ie, no water in the oil. So at least the timing chain gasket didn't go bad in the time chain cover.

But I am wondering, isn't there a top half of the timing chain cover too, in that area? Or could it be that the gasket for the water pump just gave out due to the combination of enduring two sub zero winters, and good pressure from a new radiator? Maybe something else? This is a real head scratcher, and I need to figure it out pretty soon. 2 gallons of coolant since Dec 16th is pretty major. I was hoping someone here had a similar experience and has heard of this problem before I have to get back to work on Jan. 2. I wish I had more clear view of this leak.

Thanks in advance.

 

You can rent a cooling system pressure tester from your local parts store, then pressurize the cooling system to get it to start leaking. Crawl around over/under/around it, and see if you can see exactly where it is leaking from. My timing cover was leaking right at one of the coolant passages, externally. Nothing in the oil, but, sure made a mess on the floor......

 

With all due respect, please re-read my post, as you've asked questions about things I have already covered, printed in my post. Thank you nonetheless for the reply.

 

So your description sounds like the water pump seal is leaking. Maybe it jumped the track and got pinched during install. Not sure if you can get a new seal. Pull it off, clean area real good them coat the seal with permatex black, a nice coating on both sides. Reassemble and torque bolts to finger tight. Let it sit for around an hour, then torque all the way, gradually and alternating in criss-cross pattern till tight.

 

Hi, I bought a new seal yesterday for the water pump from AutoZone, for 2 bucks, in case it really is that seal. I believe Wal Mart sells that Permatex black here locally. And I'm pretty sure when I put in the new water pump I didn't put anything but the seal then. No leaks until the new radiator was installed about 2 years later. Man I hope your hunch is right, and it's not the timing chain cover. I'm told those are a pain to do. Thanks for taking the time to read and reply Dodgevity, much appreciated.

 

If you know where it is leaking from, then you know what you have to do.

Where you losing any coolant prior to the radiator replacement? (aside from when it was obviously leaking, so your replaced it.......) I always put some RTV on the water pump gasket.... the surface is notorious being uneven, and if you don't basically spit-shine the mating surfaces, you can end up with leaks. And I hate doing the job twice.

Timing cover is only six or eight more bolts once the water pump is out of the way. Gotta be careful with the timing cover/oil pan gasket area though, gasket likes to tear when you take the cover off.

 

timing cover requires pulling the balancer, one royal job.

I used permatex gray on my WP gasket.

It's possible that a bolt or two came loose, and stayed sealed until you changed the lower radiator hose, thus moving the WP ever so slightly.

 

@magnethead, you suggested the lower radiator hose replacement may have moved the WP., may have moved it slightly. I wonder if I could simply check the bolts, or do you think I'd make it worse by tightening them up while the motor is cold? Thank you for the idea. Also, why did you choose Gray over Black?

@Heyyou, I only have an idea of the general location where the leak, which is why I am fishing for some educated guesses. I bought the new seal simply as a contingency that was cheap, if it doesn't get used right away. Prior to the radiator replacement? If you mean the water pump I replaced a couple years back, the weephole was the location. If you mean the radiator, a crack developed on top of the plastic part of the radiator, that connects to the upper hose. A small bit of steam from the crack, and coolant blow back on the upper hose. Coolant was also seen streaming down from the upper hose, down the radiator face, and to the passenger side, which would make sense, since my Dakota is parked on the street in front of my house, and the street leans to the right.

Now when I had the new radiator on, the leak appeared at the same side, but there was nothing wrong with the radiator itself. I saw coolant from underneath, on the lower WP hose and thought the new hose clamp just wasn't on tight enough. So I fixed that, and it stopped for a bit, then the leak came back with a vengeance a couple days later. Which has me thinking of magnethead's suggestion might hold some truth.

Here's the odd thing I've noticed today. I drove the truck today for about 3 hours in the city, and I only lost a couple cups of coolant tops. Before I signed up and made my first post here in the forum, I had lost that much just by revving the throttle up while my truck was parked. So what gives? Is the pressure different when the truck is driving vs. revving it in Park?

Anyway, I can't work on the truck until Saturday morning, Time will tell I suppose. Thanks for the input HeyYou.

 

Grey or black RTV will work. Just time it before you torque it down, so it firms up a bit. If I were you though, I would be very sure of the leak source, before I go pulling stuff. Spend some time with a strong light. Also, a cheap UV light (walmart) and a dark garage is good too... coolant glows under UV light. As suggested, you can alsso pressurize the system with the rental tool, or have a shop show you the leak for a few bucks. The pressure tester allows you to zone in on the leak, without having to deal with engine heat or moving parts. Pump it up to the max PSI marked on the rad cap.

 

The problem has been solved and fixed. The UV light showed as much detail as the flashlight did, but I'm going to keep it, and I saw no need to waste money on a pressure tester rental or mechanic. So anyway, I was all set to start the tear down, then I thought about how I really couldn't see the whole bypass hose. Going on my hunch, I decided to remove the compressor and alternator, and the big honking bracket over the bypass hose. Sure enough, I wasn't seeing the whole hose, nor could you with all this stuff over it.

The hose was bloated like a balloon, so I squeezed it and waddayaknow? 3 streams of coolant gush out. Ran to NAPA auto parts, replaced the hose, viola. Everything is bone dry. Put everything back together with no issue, and drove it 60 miles today. No leaks.

So I just wanted to thank you for your time and help here on the forum. If the mod wishes to close this thread, feel free. I included a pic of the actual truck in question.