Possible radiator hose issue

[TheJMan]

I've noticed lately that if I let the engine cool down for an extended period of time, the upper radiator hose looks like it has been sucked flat. Kind of reminds me of those foodsaver infomercials, when those bags have all the air removed. I replaced the radiator cap and that didn't help any. Temps run around 195-210 verified through a handheld scanner. Anyone else had this problem? Or is it normal?

 

[Lloyd10977]

I've noticed lately that if I let the engine cool down for an extended period of time, the upper radiator hose looks like it has been sucked flat. Kind of reminds me of those foodsaver infomercials, when those bags have all the air removed. I replaced the radiator cap and that didn't help any. Temps run around 195-210 verified through a handheld scanner. Anyone else had this problem? Or is it normal?

I noticed this same occurence on my OHV V6 and upon investigation, O found that the return hose running between the reservoir and the radiator cap had a small blockage. Apparently, when the radiator was under pressure while the engine was running, coolant was pushed through or around the blockage. BUT, under vaccum, when the engine was cooling, there was not enough pressure (as in vaccuum pressure) to overcome the blockage, so the effect is on the next path of least resistance, the UPPER RADIATOR HOSE.

The fix is simple: remove the reservoir return hose from the radiator cap connection and from the reservoir. (Use a golf tee to temporarily block fluid from the reservoir.) Use compressed air to blow out the hose. Make sure to blow in both directions to ensure the clog is removed. Reconnect the hose and you should not longer suffer from the collapsed upper radiator hose when the engine cools.

 

[TheJMan]

Cool, thanks for your help!

 

[Lloyd10977]

Please make sure to post and let us know your progress. I tried to do mine using a wire but could not get one long enough to push the clog completely out, and blowing through it was not quite strong enough. When I got it out, I found that it was some sort of sludge mixed with dirt/crud that had settled to the bottom of the reservoir. It seemed almost solid when cold, but was somewhat pliable when warm.

 

[TheJMan]

Please make sure to post and let us know your progress. I tried to do mine using a wire but could not get one long enough to push the clog completely out, and blowing through it was not quite strong enough. When I got it out, I found that it was some sort of sludge mixed with dirt/crud that had settled to the bottom of the reservoir. It seemed almost solid when cold, but was somewhat pliable when warm.

Your advice was right on the money. The hose going to the radiator from the overflow tank was clogged with a yellow-brown sludge. I used a garden hose and forced a high power jet of water into it that removed the clog. However, there was the same sludge at the bottom of the overflow tank, I flushed that out, and all is well. It concerns me that some of this nasty stuff may be floating around inside the engine.

 

[Glacier991]

Doncha JUST love this board?

 

[TheJMan]

Of course, this place kicks ass!

 

[Joe Wakefield]

I just did the head gaskets in my 2000 ford ranger 4.0 ohv. Everything is running beautifully. Went out to run a few errands, I was out long enough to get to temperature. I checked under hood and hour later and noticed the upper radiator hose was flat. I read the above comments but because I did the head gasket I was wondering if I should be looking for a different problem. Any advice would be greatly appreciated