Collapsed upper radiator hose ????

[Jomar]

After my truck has been setting all night,the upper radiator hose has about a 6" lenght that is collapsed. Anybody had this happen or know the reason why ? Coolant recovery cap, or thermostat maybe ??? When the thermostat opens, it goes back to normal.Are you there dmaxallitech ??


Jomar
jgmg@gvtc.com

[a64pilot]

Not since the late 70's. Had a 340 that blew the head gasket between no's 3 and 5. Hope that is not what has happened to you.
Have you had to add any coolant?

[DmaxMaverick]

If the coolant level is on par, it sounds like a cap. If the pressure valve sticks closed, the condensing of the coolant will cause a vacuum in the system, colapsing a hose at its weakest point. Like most anything, it will take the path of least resistance, which is the upper hose. The lower hose will have more pressure (although very slight, but enough) than the top hose, unless your truck is upsidedown. It is important to correct the problem. If it is the cap, it may be failing under pressure, as well. Overpressure is not a pleasant experience.

It is not likely the thermostat. The system is a closed loop and pressure will be equal on both sides of the thermostat when the engine is off.

A marine engine may be different. Some use a displacement type water pump (as opposed to a centrifical type for automotive) and a thermostatically controlled bypass valve to regulate engine temp. This is not the case with the Duramax.

[DinoMax]

Jomar, hate to say it, but that is usually a sign of head gasket problems :( :( Have the system pressure tested by a qualified shop (preferably a GM shop, especially if you are under warranty). Hope that's not the case, but get it checked before it gets worse. There has been too many post as of late w/ head gasket problems. Good Luck, DinoMax

[GM Smitty]

My truck has done that since I brought it home. 30,000 miles and no signs of any problems. I thought this was discussed awhile back and it was determined it wasn't a big deal?? :confused:
The hose doesn't completely collapse, but just gets sucked in a bit. Should we fellas with collapsing hoses be concerned?

[mdrag]

Originally posted by Jomar:
After my truck has been setting all night,the upper radiator hose has about a 6" lenght that is collapsed. Anybody had this happen or know the reason why ? Coolant recovery cap, or thermostat maybe ??? When the thermostat opens, it goes back to normal.Are you there dmaxallitech ?? I had this occur on one occasion about 1 year ago, and posted the same question. It's never happened again, and no cooloant loss ever.

[mdrag]

You know it's been a bad day when you have to correct yourself :eek:

See my post from Nov 2002 (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=3;t=004427)

In retrospect, it was the next week when my fuel filter failed - and I had even more severe starting problems than described in this post. I can't see how they could be related :confused:

[Jomar]

This afternoon when I got home and let the truck set for about 3 hrs, I raised the hood and the hose was beginning to collapse and the coolant level was normal. I loosened the tank cap almost all the way and the hose popped back to normal. I`ll get a new cap tomorrow and see what happens. My truck has 36345 miles on it and I have extended warranty. Thaks all,


Jomar

[dmaxalliTech]

Jomar, sounds like your on the right track with the cap, make sure to get oem, not aftermarket. Might not be worth the trouble getting the extended warr to cover it. But its worth a try. Sorry took so long to respond.

[mackin]

I too like Mdrag had it happen once ..... Headgasket ??? Dunno if I would go that extreme without some simplier possible issue ruled out .....

I have lost no coolant ,purrs puuurfect,still today, many hard miles later .....

Good Luck .....

Mac

[a bear]

I also agree with the possibility of the cap or a no issue. It is the character of glycol to expand more than most fluids with heat and then contract also more than most when cooling. Especially Triethelene. If a head gasket you would loose fluid to the base, exhaust or externally.

[MadDuraMax]

I had this happen on my d*dge. Look at the simple stuff first. Make sure the siphon tube to the tank line is unobstructed. Blow a little air through it etc. Mine had a small of flash, paint or other gunk in it that was enough of an obstruction.

Next is the cap, cheap to replace. After reading all of the Dexcool nightmare stories, don't take the cooling system trying to pull a vacuum that lightly. If it won't pull coolant, it might pull air next! The system should always pull from the tank when cold.

[letsgo]

If I

[Jomar]

I`m running a little late tonight but here`s what I did. Went to the dealer this morning and got a new cap for the tank, put it on , drove around til the engine was good and hot then parked the truck. I raised the hood about 9 hrs later and no problem. The service mgr. told me he was pretty sure it was the cap that was causing the problem and looks like he was right. Cap was only $7 too. Thanks to everybody for your comments, and thanks to the DP.

Jomar

[mdrag]

With somewhat cooler temps, I again noticed that my upper radiator hose was partially collapsed (http://community.webshots.com/photo/76034334/93508928EyRPvA) after the truck sat overnight. Looks like it is time for a new cap.