I have coolant leaking out and I can't figure out why. About a month ago, I changed the coolant to a 25-75% mixture by dropping the front plate & draining the coolant from the lower pipes, swapped coolant, bled system (heater on), all seemed well. The car was running fine, several hour long drives over multiple weekends happened with no issues. Took the car on a charity drive & did a few redline shifts (probablly not related) and when I got to the destination an hour away, antifreeze was leaking from under the front plate. Refilled the empty resevoir before I drove an hour home with an eye on the temps - no issues. Got home & the resevoir tank was almost empty (no surprise). It seems that the leak is more pronounced at slower speeds and that when the car is running, it's not significant, though obviously I can't confirm this. I pulled the hose, cleaned the fittings, re-attached the hose clamps, filled the system- fine. brought up to normal operating temps - bled the air out - no leaks. Went for a drive around the block - started leaking out (saw it when I stopped). Common sense says I futzed-up the hose/hose clamp. Looked like the leak was the back of the lower hose. Took it apart, used new hose clamps, made darn sure there were no leaks, refilled, Operating temps, bled, no leaks. Made sure the coolant was circulating in the tank. Yep. I did notice the water pump makes a slightly different pitch noise when I have the cap on or off. Pressure related I think. Took it around the block. Leaks. everything apart, re-checked, refilled, re-bled, super-tightened the clamps - no leaks. Went for a drive around the block, no leaks. Got up this morning, backed it out of the garage - smaller drip-leak. Where it was just shy of a stream. took it for a 20 mile errand - back in garage - no leak. I'm waiting for it to cool to see if the resevoir is empty. It doesn't sound it. so I'm about to get under the car again. I find it hard to believe I still haven't gotten the hose/clamps right as I've done this before with no issues. A mechanic friend suggested I'm simply not getting all the air out of the system & it's finding the weakest link in the system & releasing pressure. Does this sound right? I'll be checking/replacing the hose in case there's a hole/cut in it that I missed. But the rubber seemed fine when I had it off. Ideas? BTW: Just checked. The resevoir is not empty, but high. The cap is probably only 1.5 years old .
This is a much overblown problem...with a very simple fix. 1-We're going to presume that there are "zero" leaky hoses. 2-The caps on the expansion tanks are junk. Have someone with a proper "radiator cap tester" verify that it does indeed hold the specified pressure. 3-Presuming that it does, do nothing! That's right, do nothing, as if the system is overfilled...as most of them are, the cap will correctly relieve pressure until the proper level is acheived. If the expansion tank cap does not work and seal 100%, you will be for forever and a day chasing air in the system... Questions: PM me. Best, David
Also check the lip around the radiator my 308 had almost the same problem,the solder on the tank had cracked and found core was weak.New core no leaks only $350.00 to fix
Gee Clyde, if it seems to be coming from up front, by the hoses, then something up there is in trouble. Did you put new hoses on or reconnect the originals? Sometimes they (old ones) have a "set" position they want to be in. If you did change the hoses and still have this problem is it possible you have a pin hole leak in the aluminum tube (running through the chassis)?
This was my thought. But the leak in the aluminum tubing would have to be more than pin-size to account for the initial droppings of antifreeze. There was lots of antifreeze on prior adjusting attempts and little this morning. That's why I was thinking it had to be an ill-seated hose instead of hole/crack. I'll swap out the rad cap (even though the current one is fairly new) and if that doesn't do it, replace the lower hose. I checked the resevoir tank - no signs of any leakage there. Thanks!
Clyde, Sorry...I misread your post. I thought the coolant leak was coming from the expansion tank. David
Not sure what you mean by front plate, but if you are referring to the skid plate on the uderside of the body below the front end (radiator) then you could have a leaky radiator, in any case, you can't fix the problem until you locate where the leak is coming from. Radiator and coolant leaks can be elusive, and a static pressure test with a flashlight and visual access to the entire system is the only way to diagnose it. Sounds like a lot of conflicting info here, and it sounds like you have not located the leak. If it was the cap, the leaks would be under the engine (if you have a drain hose and coolant collect tank under the hood) not under the radiator. Air in the system will cause overheating by preventing coolant from reaching certain areas of the engine or radiator, or disable the water pump partially, but will not help or hurt a leak. If all else fails go to a radiator shop and pay for a pressure test (while you watch),.
You need to (refill and) pressurize the system (with the Stant hand-pump equipment) when cold so you can determine where/how it's actually leaking out before you can know the fix. (It's not an easy test to pass as the rubber hoses aren't so piable at the cold temperature so fix any other leaks that show up too )
That be the plate. And you folks are right, conflicting indicators. Guess the next stop is a pressure test.
When something is changed and problem develops, examine the change. There is some chance that the force use to remove the hose from the bottom of the radiator, that a crack developed where the metal spout is soldered to the radiator. I'd examine that carefully.
Might be helpful to get the car on a lift when she's hot and pressurized....let her idle on the lift (that'll bring the coolant temps up) and use a shop light to try to pin point the source of the leak...
I have a guess. There is some corrosive action between air, coolant and aluminum/brass/steel with old coolant. All the corrosion issues I've had with coolant have been at the water line in the top of radiators/expansion tanks, where hoses are clamped onto nipples, etc. When you drained the lower radiator hose the first time, is that the spot where it now leaks? If so I think you might have a very small hole in the aluminum tube that was inside the hose clamp and is now very slightly outside the hose clamp. I'd remove that hose, examine the aluminum pipe carefully. The easy fix would probably to use a slightly longer hose and move the hose clamps back a little bit and put the hole back on the inside of the system. After seeing what old coolant has done to my GT4 and an emergency power generator I am a vocal convert: Change you coolant every few years! Old coolant eats metal.
I've noticed that the Ph drops as time passes. Initially with ordinary antifreeze mixture (green stuff), the Ph is well over 8 when first filled. Let 2-3 years go by and the Ph drops into the 7+ range. It starts to get hungry as it nears 7. I change mine every 2.0 - 2.5 years. Seems to work. Knock on wood, I've never had to replace any coolant component on any car other than leaking water pumps and I tend to keep cars a long time.
when you say the coolant gets hungry as the pH approaches 7, do you mean it starts to corrode the aluminum faster ??? (maybe that's what happend to my cadillac ? Old coolant causing the head gaskets to leak?)
Yes, the initial mixture is caustic (upper 8's). As it tends towards neutral (7.0), metal begins to disappear.
Found the problem! Pulled off the hose again to check the aluminum pipe. The pipe was fine. But I happened to notice when I bent the edge of the rubber hose, there was a small crack where the hose-clamp was that went clear-though to the inside of the hose. Bingo! Frassin-rassin-bassin-bing-bong virtually invisible crack. No napa dealer in 25 miles of me had the gold-stripe hose #633 (3' of 1-5/8") in stock. It could be ordered in a couple days for $50. I have a drive tomorrow, so I needed it fixed now. My local auto store had a Gates 24026 coolant hose (41mm,1-5/8") hose. 12" for $10. Done! I have it on & am re-filling the coolant now. so far, no leaks. Let the bleeding commence!
Good deal that you found it and it was an easy fix. I was going to ask if you went to the trouble of pulling the clamp off why not just replace the hose while there, but you were one step ahead! Have a great drive!
in the future, buy yourself a pressure tester. It's about $100 and it pressurizes the system "cold." It will save you hours and driving around, getting the car hot, and waiting for it to leak.
