Coolant overflow tank empty every couple/few weeks. (1 Viewer)

[JCruse]

My overflow tank keeps turning up empty every few weeks. I don't see any puddles under the truck or other obvious signs of leakage and I'm wondering what, besides the HG, could be the cause.
(I really hope it's not the HG.)

I replaced the radiator cap but that didn't fix it.

 

[ppc]

Have you looked at the condition of the PHH?

 

[Paul_L]

Also check the bypass hose above & forward of the PHH, that's where my leak was.

 

[Michael Hanson]

Hi, Check rear heater hoses. Mike

 

[KoalaCruiser]

Have you pulled the overflow tank out? Mine had a hairline crack although there was some leakage.

 

[JCruse]

Great, thanks guys, I'm gonna check all these things ASAP.

I can't see much of the PHH but I saw no coolant under it.

Not sure which the bypass hose is but I'll look there too.

Wouldn't I smell the rear heater hose leaking?

 

[Paul_L]

Not necessarily, mine leaked for a long time & there was never a puddle & I only rarely smelled coolant. The bypass hose is a small diameter hose that goes from the head to the bottom of the throttle body. Mine was leaking where the clamp had cut into the hose. I was able to cut about 1-1.5 inches off the lower end & reconnect it for a temporary repair.

https://forum.ih8mud.com/80-series-...coolant-leak-but-what-hose-where-does-go.html

https://forum.ih8mud.com/80-series-tech/766230-phh-time.html

 

[jonheld]

The coolant system becomes pressurized when the engine gets up to temperature. A loose clamp could cause a leak that would be difficult to spot as the coolant would blow around while driving. As the system cools, it wouldn't drip due to lack of pressure.

Check the motor oil for coolant contamination to rule out HG issues.

With the coolant system full, drive around until the engine is at NOT and let her sit for a while at idle in your driveway while you crawl around looking at the obvious.

 

[alia176]

My overflow tank keeps turning up empty every few weeks. I don't see any puddles under the truck or other obvious signs of leakage and I'm wondering what, besides the HG, could be the cause.
(I really hope it's not the HG.)

I replaced the radiator cap but that didn't fix it.

Slap some cardboard under the engine bay after you top off the coolant and go for a "spirited" ride. park overnight and see if any indication of coolant loss. On my '97, a freeze plug behind the head (between the head and firewall) was a major culprit for coolant loss.

Let's get a little more objective about quantifying the amount of coolant you're losing. Place a short piece of vertical tape on the coolant res and mark the levels with a Sharpie.

After the engine is warmed up, rev the engine to 3500rpm and look for bubbles in the res tank, let's hope not!

 

[Otamiway]

My overflow tank keeps turning up empty every few weeks. I don't see any puddles under the truck or other obvious signs of leakage and I'm wondering what, besides the HG, could be the cause.
(I really hope it's not the HG.)

I replaced the radiator cap but that didn't fix it.

All good suggestions for far. Take your time and you will find it.

Here is what happened to me.. Overflow Bottle always Low


Good luck.

 

[newtomelx]

Overflow coolant missing

I was experiencing the same issue for the last several months, was unable to locate leak until it got much worse. I then noticed that the crimp connection on the top of the radiator, where the tank is crimped to the core, was oozing coolant out. So I have a new radiator (3 core copper TRAD) from Beno to replace this week. I had no noticeable external signs of the leak until it got so bad that it was clearly evident where it was coming from. Good luck in your endeavors!