Very slow coolant leak

[4Runner4TW]

My truck has a slow leak at the upper radiator hose for some years now. Two years ago I replaced the hose but the leak is still there. Today I noticed my coolant reservoir was below the MIN mark. Could the water outlet have a crack? This truck has spent its entire life in AZ. What are your thoughts? (Picture below is not my truck but is similar, just not nearly as bad as the picture below)

 

[4Runner4TW]

Part number 12 on here, $30. Looks like a few bolts.

 

[shahsmerdis]

My truck has a slow leak at the upper radiator hose for some years now. Two years ago I replaced the hose but the leak is still there. Today I noticed my coolant reservoir was below the MIN mark. Could the water outlet have a crack? This truck has spent its entire life in AZ. What are your thoughts? (Picture below is not my truck but is similar, just not nearly as bad as the picture below)

Did you replace with OEM?

Sure its securely on?

Did you do a transmission cooler bypass?

 

[LittleCaesar]

Are you using a worm drive clamp to attach it? When you pull the hose off check that housing for any hairline cracks. They do occur.

How does the oil look? Any wetness on the front of the block?

 

[stir_fry_boy]

There also has to be a gasket on part #12.

If you need help or extra OEM coolant, I have some and live in Cottonwood. We can have you fixed in no time.

PM me.

 

[4Runner4TW]

Did you replace with OEM?

Sure its securely on?

Did you do a transmission cooler bypass?

Hose is OEM, replaced 2 years ago. Tightened down as hard as I could. I did bypass the transmission.

 

[4Runner4TW]

Are you using a worm drive clamp to attach it? When you pull the hose off check that housing for any hairline cracks. They do occur.

How does the oil look? Any wetness on the front of the block?

I guess that is my next step, take off that hose and look for a crack.
Oil is fine. No leaks on block.

 

[4Runner4TW]

There also has to be a gasket on part #12.

If you need help or extra OEM coolant, I have some and live in Cottonwood. We can have you fixed in no time.

PM me.

Have you replaced part 12? Thanks for the offer. I'll investigate more when I get home. I'm jealous you have the new TRD Pro! I think I've seen you around.

 

[LittleCaesar]

I forgot to ask if the cap was still original? If it is consider replacing it with a new OEM one.

 

[stir_fry_boy]

Have you replaced part 12? Thanks for the offer. I'll investigate more when I get home. I'm jealous you have the new TRD Pro! I think I've seen you around.

I haven't. I am sure there is a gasket there. Metal doesn't seal against metal very well, it needs rubber or silicone to get a tight seal. Like [MENTION=69868]LittleCaesar[/MENTION] said, could be a hairline crack in the aluminum causing the leak. You would have to drain coolant to see it.

There are a couple TRD PROS in Sedona. I have a white one. I see a black one all the time.