Coolant Leak, Holding Pressure - Cummins ISX

You have to get up underneath & see where it is coming from. It could just be a clamp the rubber expands & contracts from getting cold & hot.

 

Take a look for the leak. Nobody can tell you the exact location and nature of a failure based on a picture of a puddle on the ground.

 

Being where it’s at, might be a heater hose, going to the cab or bunk heater, or APU. Shouldn’t be too hard to open hood, turn steer tire enough to see the source. Maybe there’s a water valve you can turn off, till it’s fixed.

 

I was losing coolant and it wasn’t leaking into the ground, I posted a thread about it. At the end, the coolant was leaking thru the transmission cooler that sits on top of the transmission. The coolant was going into the transmission. Eventually, the transmission gear oil started leaking. The coolant going into the transmission was making the gear oil over flow, first it starting over flowing thru the breather on top, I extended the breather with a hose, it stopped for about a week then is starting leaking(gear oil) thru the front transmission seal. So I ended up bypassing the transmission cooler and problem solved, and also drained and refilled the transmission gear oil.

Also, on a separate incident, I started leaking coolant and couldn’t fined it until I got under the truck. There is a hose that runs along the frame on the passenger side and the only way you can see it is looking thru it underneath. Mine ended up just being a loose clamp. I tightened the clamp, coolant stopped leaking. This is on a 2014 Pete with a ISX 15.
Goodluck, let us know what you find out.

 

Diesel Dave. When you fixed that leak on the passenger side did you have to drain the coolant? I just noticed that same exact leak on mine today.

 

I had a loose hose clamp. I just tightened it up.