I've had to put maybe 1/2 to 3/4 gallon into it since I bought my truck a couple months ago. Have put around 350 miles on it. Also I noticed my overflow reservoir is a lot more full.. it already had some pretty nasty looking coolant in there.

So I'm wondering whether that would be considered an excessive amount of coolant to lose, and whether it just ended up in the overflow reservoir somehow? Also how should I drain the reservoir?

 

get a pressure tester. slowly increase system pressure until you find your leak. also test your cap.

 

How do I know whether it's leaking or being burned off? I'm having a lot of smoke issues and it's a whitish grey, so I was thinking it was just the injectors and/or IP, but now with the coolant I'm just wanting to make sure that wouldn't point to a head gasket issue.

I also have a bad CDR valve it seems because the air filter I took out was covered in oil, so I'm hoping that didn't lead to head gasket wear.

And I'm not sure how much but some coolant has ended up in the overflow reservoir. When and why is it supposed to go into there?

 

Ok so assuming you have a full radiator, when the rig warms up the water expands, it has to go somewhere, aka the overfill tank. If everything is working right however, when it cools back off the radiator should pull the coolant back out of the overflow. Mine would not do this, i replaced the cap and smooth sailing ever since.

Take a whiff of the exhaust after she warms up and see if it smells sweet at all. Also, verify that the oil is not milky colored ( have to check right after you turn it off, after it has sat the water will seperate to the bottom of the oil pan if it is present)

 

I gave it an oil change and it was never milky at all. Never a sweet smell to the exhaust just rich. As far as I can tell, I just have the tube going to the top of the overfill reservoir, and no way for it to get back into the radiator. Am I missing something? It's almost full now so it must not be going back in there.

 

IIRC there is two types, the one with the nipple in the bottom of the overflow, and the one where the hose goes through the top. With the second, i believe the hose should go in and be able to reach the bottom. So you might verify that it is at the bottom and not just sitting at the top.

But i agree with the pressure tester. Pump your radiator up to 15lbs and see what happens, it should hold.

 

Ok so I'm still stumped about my coolant overflow tank.. I'll take a picture later on, but I'm almost positive there's no tube or nipple on the bottom, it's just a tube that goes into the top. However the tube just connects at the top and doesn't actually go inside of the tank, so the coolant that ends up in there just stays. It also looks pretty old and fowl and I wouldn't want it going back in at this point, will definitely change out once I figure out what's going on.

 

Shove the tube farther in so that it's basically riding along the bottom of the tank. This will allow it to suction in fluid as it cools. On my 91, the OD of the tube sits along the ID of the plastic nipple in the top of the tank and has a metal clamp that holds it with just enough pressure to keep the tube from backing out. To adjust the hose, all I had to do was slip off the clamp, slide the hose in further, then slide the clamp back on.

Mike

 

^^
What they said. The tube needs to be covered in liquid to work properly. If its not reaching the bottom of the tank, it won't be able to suck the fluid back in as the radiator cools.

My advice would be to either stuff the tube in farther like whiteboyslo said, or replace it with one thats long enough to reach the bottom. Then drive it for a while and see if you still need to top off the fluid. My guess is that you'll be fine if you fix the tube, and nothing else is wrong.

If you want, take the coolant reservoir off and clean it out first.

 

Mine has a metal clamp that holds the hose on. Not sure if there is enough hose to pull it through to the bottom, do you know what size replacement I should get?

Zac