Three years ago to date, the original radiator began leaking from the side plastic and dealer fitted a new one. About 2 years ago I installed a new hose assembly due to one of the composite plastic couplers in the assembly splitting a seam. This massive assembly includes upper and lower radiator hoses, plastic inter-cooler lines and hose to the front crossover pipe.

Yesterday I noticed the upper radiator hose had slid about half and inch away from the base of the outlet on the radiator. I used my special quick release tool and slid the hose forward to it's correct position. Drove around quite a bit today and stopped at Shell station near my house for a fuel top off. Everything was fine until about a mile from my house I received the dreaded low coolant warning and shortly after billows of steam as I drove (it's in the 40s F tonight). Monitored coolant temp and no issue. Pulled into the garage and opened the bonnet and coolant everywhere in the bay and coolant soaking the entire right side of the truck, under carriage, even the wheels, tyres and wheel wells. Rinsed everything off and began investigating. Expansion tank was not completely empty and I refilled it. I noticed the upper radiator hose I had moved the day before had slid itself about a quarter of an inch back and that's when I noticed the plastic right side of the radiator had spit from the radiator.

Over the past several months I have replaced many parts to the cooling system, including water pumps, hoses, seals, etc. And this isn't the first time for many of these bits. During the time, I've observed the upper radiator hose getting rock hard. In the past I know I've squeezed this hose with minimal effort. Perhaps I'm paying more attention to it now, but does anyone know if this's normal? What I'm wondering is if there's too much pressure building. I've always the habit of opening the bonnet and expansion tank cap when I arrive home so as to help with cooling and relieving pressure. My concern's replacing the radiator only to have this happen again. Seems odd and too much of a coincidence for this truck to need a third radiator.

 

When you say you have to relieve pressure… is coolant overflowing or coming close to overflowing and relieving the pressure lowers the level

or

is it being sucked into the block/radiator then filling the overflow when pressure is released?

 

Good question. I loosen the cap to relieve pressure as I've replaced nearly every pipe and hose on this bloody thing and I feel doing so may help with stress on various bits in the circuit. When I do this, typically coolant's below the fill line and there's a lot of hissing as the coolant level rises to the cap on the expansion tank. I wait a bit and do it again until there's no more hissing. After several hours the coolant level in the tank lowers to the fill level.

Have you noticed your upper radiator hose being exceptionally firm at any time? Would this be considered normal or is excessive pressure building and causing things to keep breaking in the circuit. Most recent cooling circuit repairs of 2023: o-ring failure on 2-year old o-rings & coolant pump number 2, inter-cooler pump replacement, water pump to t-stat hoses, throttle body hoses, expansion tank and connected hoses, lower left radiator hose to t-stat (began leaking at the radiator fitting) and another hose.

 

I’m intrigued BC I may be experiencing similar issues.

Could be an airlock. Could be a Headgasket. Could be many things…

 

Mine has residual pressure the morning after it sat all night.

If I remove the expansion chamber cap, pressure is released & the coolant rises back to the cold fill level.

 

Yes mine does the same. Not certain if it's always done this, but I have been monitoring for several months since I've been replacing more parts. Cooling circuit first started failing in 2018 at 3 years of age then again in 2020 and ever since.

 

It’s been doing this for months? Have you attempted to diagnose? If so what have you done

 

I've replaced parts as they fail. But now with a radiator less than 3 years old blowing out the side and constant hose failures, I've been wondering if it building too much pressure or if that's even possible. ECT temps have been at around 206 F.

EDIT: Or perhaps all's normal and parts quality's just crap...

Hoping those with experience can offer insight.

 

I run my Gap tool in live value mode and my coolant temps hover around 195 so you’re quite a bit warmer than me.

I think we have airlock (big air bubble).

I worked mine out a bit yesterday by parking at an incline & opening up both heaters. Thrn, alternating periods of idle & high RPM (2,000/3,500)

 

Could also be blown Headgasket