Collapsed upper radiator hose

[Learjet]

I found my upper radiator hose collapsed and it stayed this way for days...opened the reservoir cap and still had a vacuum 72+ hours later. I've had this problem on other trucks I've had....and changing the cap didn't seem to help.

2017 with 35,000 miles....what do ya'll think?

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[Cummins12V98]

I think I would have the Dealer fix it.

 

[BarryG]

Shooting in the dark here but when something hot gets cool/cold it creates a vacuum. The expansion of the coolant when it gets hot forces coolant into the overflow/expansion bottle and as it cools the vacuum created pulls that coolant back into the radiator. At least that is more or less how it is supposed to work. Could it be that the overflow/expansion bottle tube is blocked, pinched etc.

The pressurized coolant at temp could have enough pressure to open the blockage to allow coolant into the bottle or at least did at one time as the radiator/cooling system (sans the expansion bottle) must not be full at the moment otherwise the hose could not collapse as you cant compress fluids and if I recall correctly the expansion tank has a vent somewhere.

I know that my 17 cooling system is different than my 01 was for sure. The 01 was just a simple expansion tank with the tube running to the bottom of the tank and there was a simple vent on the top of the tank. While I have not looked hard at my current cooling system it is certainly different and at least from the looks of it more complex in regards to how the expansion tank works but the principle should be the same. Also on the 17 there is the egr cooler that could be leaking coolant (ie losing coolant but no visible signs of it) and then as the radiator cools it is creating vacuum and collapsing the hose since it isn't full.

Hopefully someone more in tune with the 17 cooling operation will chime in

 

[nukegm]

had a old 70 bronco that would do similar to the lower hose....so i put in a large coil spring inside the hose, and problem solved. i got the spring from a local auto parts store. it was inside a stocked hose for some other model vehicle. if it were me , however, id take it to the dealer too as was stated above. cheers! let us know how it got resolved.

 

[B.G. Smith]

The radiator cap controls the expansion and contraction of coolant by allowing it to flow to reservoir when hot and allowing coolant to be drawn back into the radiator when it cools off, not the reservoir cap, bg

 

[Learjet]

The radiator cap controls the expansion and contraction of coolant by allowing it to flow to reservoir when hot and allowing coolant to be drawn back into the radiator when it cools off, not the reservoir cap, bg

not in 2017...there is no radiator cap...the reservoir is the only cap.

 

[B.G. Smith]

Regardless of where you put the cap, it still works the same.

 

[AH64ID]

Should still be under warranty, so I’d let Ram fix it... thou I do hate them working on stuff.

 

[Wiredawg]

I've had this happen on 3rd Gen after replacing coolant.... first startup after. all I could figure out was the thermostat was stuck closed and the vent valve wouldn't burp the system. The hose has to have vacuum to collapse, so there has to be a blockage on upstream flow, if that makes sense. What makes this harder to me is where the radiator cap is not on the radiator. You may need to inspect the thermostat or have the dealer do it. Maybe call em and ask em

Cheers, Ron

 

[TFucili]

Ran across this post on another forum:

Pretty sure I found my problem. My overflow has been reading almost to the top of the bottle so I was thinking that should start by taking some coolant out. So I took the bottle off and drained to the right level. Thought I should check the rubber hose leading to the bottle. All good there. Thought it would be fun to blow though the hose end of the bottle to see some bubbles and nothing. Darn, that was no fun. So I drained the whole bottle out and the small tube is totally plugged up at the bottom. Put my air hose to it and that didn't even work. Shoved a thick wire down the thing right along with some degreaser and plunggered that bugger right out. Probably over an inch of crap. So I'm soaking it tonight to flush the whole bottle. #ad

 

[Wiredawg]

Ran across this post on another forum:

Pretty sure I found my problem. My overflow has been reading almost to the top of the bottle so I was thinking that should start by taking some coolant out. So I took the bottle off and drained to the right level. Thought I should check the rubber hose leading to the bottle. All good there. Thought it would be fun to blow though the hose end of the bottle to see some bubbles and nothing. Darn, that was no fun. So I drained the whole bottle out and the small tube is totally plugged up at the bottom. Put my air hose to it and that didn't even work. Shoved a thick wire down the thing right along with some degreaser and plunggered that bugger right out. Probably over an inch of crap. So I'm soaking it tonight to flush the whole bottle. #ad

Good to know... a blockage. Anytime hoses collapse, it's due to a vacuum created by a blockage. Had the truck sat allowing guck to form?

Anyway, I feel good we understand the theory AND now have a cause.

Good thread.

Cheers, Ron

 

[jhenderson]

My money is on factory installed stop leak coagulating at the restriction.

 

[Learjet]

Update: New reservoir cap fixed this issue...$10 on ebay

 

[Cummins12V98]

Curious why you didn't have the dealer replace? I know $10 not worth a trip.

 

[Learjet]

Curious why you didn't have the dealer replace? I know $10 not worth a trip.

Yep...Between the fuel to drive there and my time...it would be more than the $10 I spent to get a cap.

FYI...I've been doing all the maintenance myself...only been to the dealer for 4 recalls and had the tires balanced and fronts rotated while I was there last time. Nothing coming up that I would need to go there for...so I just took care of it.