Leaking top radiator hose. Seems to only leak cold. Novice needs advise repairing. (1 Viewer)

[esoniat]

If the truck sits, or if I only run it for a few minutes it leaks.
If I run it hot it frequently doesn't leak.
The hose clamp is pretty tight.
The hose is reportedly in good shape.
This hose has been removed and cleaned up once and that lasted 9 months or so. I did not do that work.
I have no experience changing hoses.

What should I look for as the cause of this issue if I pull the hose?
Should I pull this hose and put RTV or something else on it?
Should I try to get a new hose. What is the id of the hose and what hose clamp size?
Should i put RTV or something else on the new hose?

Technically I am not suppose to work on it in the parking space but if I am quick I should be able to finish before they notice.
This is my only vehicle so I don't want to screw it up and have to get it towed.
I am trying to say isolated because of COVID19.
Fortunately I have a spare gallon of 50/50 antifreeze.

Your advise is appreciated.

 

[klinetime574]

I would investigate a little more and make sure it’s the hose. The thermostat housings are prone to cracking/corrosion. If you’re questioning the hose, go buy a new one and swap it, along with new clamps. A molded upper radiator hose can be found at any FLAPS. If it’s on the radiator side that’s a different story. Could be a cracked radiator or a bad hose.

 

[Spike Strip]

You can rent for free from Autozone, and other chain autoparts, a 'System Pressure Tester'.

Depending on you radiator, you will probably need an adapter for the Toyota Radiator. There are videos on Youtube on how to do this.

Pressurize the cooling system (COLD) to 13 psi and look for the leak.

Find leak. Fix.

If your truck has not been well maintained, the housing often corrodes under the hose and can cause leaks.

Can't repair the hose. If it's old or rotten, replace hose and use new clamps - The parts guys will get you the proper size. Don't use cheap clamps and it's best to double up on both the radiator and T'stat housing sides.

I would use a Toyota hose or Gates. Don't use the cut-to-fit type.

 

[Seth S]

Hoses are pretty inexpensive. Pick up a new hose. Take the old one off and inspect the surface it attaches too. You might find that surface to have pin holes due to corrosion or could be cracked. The hot engine may allow enough thermal expansion for a leak in the aluminum to close and stop leaking.

 

[Saucerman]

How much of a leak are we talking about? You have a puddle of antifreeze or just a drop or two on the hose?

 

[esoniat]

How much of a leak are we talking about? You have a puddle of antifreeze or just a drop or two on the hose?

There is anti freeze collecting in the rim around the top of the radiator and eventually it drips off the low side.
I would say it is maybe an 1oz or so every night if it gets cold.

 

[TexasBlue]

Try simple fix first. Hose and clamp. After that pressure test. My 2 cents

 

[Saucerman]

What he said. That and forget about it.

 

[Gretsch]

You can rent for free from Autozone, and other chain autoparts, a 'System Pressure Tester'.

Depending on you radiator, you will probably need an adapter for the Toyota Radiator. There are videos on Youtube on how to do this.

Pressurize the cooling system (COLD) to 13 psi and look for the leak.

Find leak. Fix.

If your truck has not been well maintained, the housing often corrodes under the hose and can cause leaks.

Can't repair the hose. If it's old or rotten, replace hose and use new clamps - The parts guys will get you the proper size. Don't use cheap clamps and it's best to double up on both the radiator and T'stat housing sides.

I would use a Toyota hose or Gates. Don't use the cut-to-fit type.

^^^ This!!! Your leak should become apparent with pressure applied to the system. HTH.

 

[MoaByte]

Funny thing, but I noticed yesterday I had a coolant leak. I pulled the radiator cap and noticed the rubber gasket has cracked up. Has yours?

 

[Zack1978]

Try using the OEM Toyota spring loaded hose clamp as opposed to the worm gear clamp.

 

[MoaByte]

Try using the OEM Toyota spring loaded hose clamp as opposed to the worm gear clamp.

Truth. Constant spring pressure is marvelous work of engineering. Give it shot. It seems counter intuitive.