Coolant, oil and transmission fluid all leak a little. The previous owner stated the engine had been rebuilt about 5k miles ago, but I dont have the details on what all had been done.

1. COOLANT LEAK: after replacing my radiator, everything appeared alright. Then today it puked up some fluid after turning it on this morning, driving 5 minutes, and then shutting her down. I can typically smell the new coolant when the truck is hot. When climbing underneath, I can see coolant dripping from one location between the radiator and fan shroud, but am not sure where it is coming from. Again, it is a brand new radiator.

2: OIL LEAK: every time i run it, park and shut down, oil drips from the drain plug. most of the oil pan appears wet but most of the block also is pretty dirty/oily.

3. TRANNY FLUID: As far as I can tell, tranny fluid is leaking where at the low spot on the tranny right after it's connected to the motor. This also is a drip after each time I run the truck and shut it down, but it is accumulating nice spots in my consistent parking areas.

What might cause each of these? Head gasket/intake gasket?

I have recently dumped almost 1k into getting the brake system operating again and want to keep using this as my work truck, safely and reliably. Will it take a tear down to fix these issuse?

 

Well, for coolant, if its a new radiator it could be over filled and its just puking up the extra coolant. Did you check your coolant cap to make sure its seating right and working properly? Also if its new and is actually leaking somewhere then it should be under warranty.

Oil leaks are very hard to track down in my experience. If your whole oil pan looks wet anyways i could check the oil pan bolts to make sure they are snug. If it actually is the oil plug then i would check to make sure it has a gasket on it and make sure the plug isnt stripped. Also check to make sure your valve covers are snug, dont overtighten though because then you will still be leaking oil lol. I suppose it could be possible that the intake gasket could be leaking as well. Maybe reach around back and see if its wet back there. or use a mirror. Like i said, hard to track down but just some things to check.

Tranny fluid leak i dont have much experience with so i cant suggest anything there really lol.

Hope this gives you some ideas and helps.

 

Make sure you use a torque wrench on that oil pan or you'll never get it to stop leaking.

 

Ah leaks. If you own one of these old trucks leaks are almost unavoidable I feel your pain.
Coolant....make sure the hoses connected to the radiator are all snug and not dry rotted. You just got a new radiator so I wouldn't suspect that to be bad already.
Oil....if the oil is truely leaking from the plug do what co425 said. It needs to be tight. The rear main seal is a common place for oil to leak from on these guys, but if the oil is on the bottom of the oil pan and not further back at all then it doesn't sound like it's a rear main seal problem.
Tranny Fluid.....I have yet to figure this one out myself. I had my tranny competely rebuilt last year and it still drips very very slow. It doesn't leak enough to worry about much, but I wish I knew how to stop it. Hope this helps good luck.

 

Thanks for the tips - hopefully I don't have to start pulling the motor apart to fix things. I'll take a look this weekend and see what I can come up with.

 

Check the hose clamps for the coolant leak. New hoses will compress a bit at first and clamp could be loose. The oil dipstick where it enters the pan is a common place for a leak. No help on the tranny.

 

If it's a c6 they usually start leaking at the shift shaft. You have to drop the pan and un bolt it to swap the o ring. It's not a hard job. Change the tranny filter while your at it.

 

Transmission leaks are hard. Just start at the lowest point you see fluid and follow the wet trail. See if it is reaching the pan from the bellhousing. Could be leaking at its front seal and dribbling down.

More often than not, the pan isnt seating right. Transmission fluid has a very thin viscosity compared to motor oil, so mated surfaces must have a great seal. Its pretty common if your transmission has had a service, which we'll hope it has. Overtightening bolts, running over tree stumps and just time can bend the pan gasket surface.

If its the pan you can remove it and replace the pan. You can also salvage the pan if you just take your time to make sure the surface is cleaned and smoothed. Dont use RTV. Transmission fluid doesnt like it and breaks it down. I have successfully used Permatex Aircraft Sealant for transmission pans. Its kinda like tar or molasses and comes in a white jar with a brush attached to the lid, but you have to make sure to keep oil off the gasket surface. Not easy on a transmission.

You dont want the bolts on too tight. Get your torque specs. Oh, and you might end up buying some heli-coils. I had to fix stripped threads on the last two transmissions I worked on (C6 and C4). People just tighten these way too much.

 

I wish Id known about this. I would have just replaced it when I did my service, as insurance.

 

This sounds like my problem as well possibly.

 

Again this morning after driving to work (a quick start up, 4 minute drive and then shut down to walk into the shop - it doesn't even warm up all the way) - I checked under the hood again to find the leak. It was dribbling down a thin, but constant - stream where I had installed the new gasket and thermostat about two weeks ago (using NAPA parts). I don't know if the gasket didn't seal or what the issue was, but I am going to get a new gasket and try to reseal it tomorrow.

Then onto the oil and tranny leak issues. I did take a closer look this morning and it is oily around the entire perimeter of the oil pan - so hopefully that is a pretty simple fix. But it does drip from the oil plug and also from the back of the oil pan - so two oil spots everwhere I park.

The tranny is just dripping from the bell housing right at the front where there is a little grooved opening.

If any of you have seen my other thread - I am also battling a serious brake fluid leak out of the front reservoir of the master cylinder. I've spent $830 on parts/labor to get the rear brakes back up and running, but the leak persists through the lid of the MC. I'm going to have the same shop check to see if the rear brake lines are leaking or if it is as simple as a faulty lid/gasket or possibly a hairline crack in the MC itself.

 

Ok, i thought you said that it was leaking between the radiator and the fan shroud but the way you describe this in your last post it sounds like your thermostat housing didnt seal all the way. Try using some of the silicone gasket stuff with the paper gasket. Some people just use the silicone stuff to make a gasket. Up to you how you want to try it though. But yeah, i thought you were talkin about the actual radiator, not the thermostat housing.

 

I assume what was happening is that it was leaking from the thermostat housing and the fan was just blowing it against the back of the radiator - thus when I crawled underneath it was dripping down between the radiator and fan shroud. I looked and wasn't able to find any other leaks right there so hopefully it is only at the housing. Not sure why it didn't seal - I used a new gasket with the silicone gasket maker.

 

Yikes sounds like this truck loves to eat up your money between all the leaks and the brakes. But for the tranny i suggest the front seal. For the oil pan valve covers and tranny oil pan if somone has over tightened them the pan isnt flat any more. Where the bolt goes there will be a bump on the inside of the pan. To fix this either get a new pan/valve cover or get a piece of steel that fits inside the side where the bolt enters and pound the bump out from the gasket side.

 

For the coolant, it might just be over filled as previously stated, if the truck is original then the leak could be coming from the overflow line running down the driverside of the rad support. You can buy a universal overflow tank from LMC fo cheap to keep the AF from driping on your floor. If your engine is gunked up the way you described it, then I would find it hard to believe it was rebuilt. Most rebuilds are with blocks that are dipped and board before reassembly, otherwise the rings would never seal properly and you'd be burn'in oil. I would degrease the engine and start ther with the oil leak. YOu mentioned by the plug, hopefully the plug is not stripped, but if it is, you can tap it out and get a larger drain plug to stop the leak there. The trany is a differrent animal, if the front of the trany has a lot of fluid then it could be the front seal behind the tourqe converter could of been damaged when the engine was supposably rebuilt. pictures are alwasy helpful, Good luck, most should be minor repairs with the exception of the trany seal. Remember never to over tighten the gaskets when you replace them, allow them to form and re tourqe them after a few hundred mile if you notice some minor leak.