Hot Rods Lower Radiator Hose collapsing

I wouldn`t make the problem bigger than it really is. Chrysler put a spring in the lower hose. If temps are fine, just push in a spring and be done with it. ... but maybe that`s just me...

 

How did you get on?

 

I went through this when replacing the hoses in my cadillac. None of the replacements (including the Gates I went with) had springs in them. I was told today's materials are superior and dont require a spring - which I think is a little BS, but I have not had it collapse yet.

I read that the springs were originally put in from the factory because in order for them to add coolant on the assembly line and not have air in the system, it had to be added under vacuum. Then they just left the spring in. The original in mine rusted and took the water pump with it I believe. So make sure you do use stainless.

 

31Vicky, my friend, please don't be upset. I knew what you meant from the beginning, of course. I just thought you stated it in a somewhat confusing manner, the first time.

That's all.

(You mixed talk about both Gauge Pressure and Absolute Pressure in the same sentence. That is the confusing bit.)

Please forgive me for seeming so persnickety over trivia folks. A part of my job is to take ambiguous notes and specifications and re-write them to remove every loophole. It's the part where engineers get to play lawyer, for our own protection. After nearly 40 years of this stuff it's become an insufferable habit, and even among my associates I have a reputation for being too persnickety.

 

That's too bad. In normal service the hose always gave out before the spring rusted away. BUT, you have to use Prestone or similar in the coolant for anti-corrosion properties, or the whole business just rusts up.

 

A parly plugged radiator has nothing to do with the hose collapsing, it is normal, and all lower hoses should have a wire in them. As for the flex hoses, I never use them, because they are so stiff, they put a lot po pressure on the radiator outlets, and can cause failure where the outlets are soldered to the tanks.

 

Put your calculators away. Grab some old seat springs and shove them in the hose. Go for a drive.

 

31Vicky, First off it's 6 in the morning and I am 1/2 asleep so who knows if I am reading any of your comments correctly...but lately at work I am playing with industrial chillers - they are quite similar to a car's cooling system, but have pressure gages in them. Here's a typical setup: I pressurize the system to 2.3 Bar - everything is turned off so there is 2.3 bar everywhere in the system. Next I turn the pump on. The pressure on the outlet side of the pump goes to 4 bar and the pressure on the return side of the pump drops to 1.5 bar. Adjust your static pressure of 2.3 up or down and everything moves accordingly. Am I stating everything you already know? Hey I'm STILL 1/2 asleep!!!!!!

 

Continuing with your if/then process; If the pressure is the same in all areas of the system then there could be no flow. Fluids flow from high pressure to low pressure. The water pump moves water by pushing water away on one side causing a lower pressure on the other side. The radiator does restrict the flow of water. This is easily proven with the radiator hoses disconnected and the cap installed. Run a garden hose into the top hose connection at full flow. Water will come out around the garden hose. Wrap a rag around the garden hose and try to stop the leak and you will feel the pressure build up while the lower hose connection is at 0 [atmospheric] pressure. The water pump in most engines is capable of creating more than a 13 psi pressure differential.

 

I agree

IF - the hose collapses

THEN - the water pump would be making more than 14.71 pressure differential at sea level
AND The radiator would providing more of a restriction than the pressure in the system can overcome.

Both the pumps suction and radiator restriction need to be true for a hose to collapse.

Bottom line I guess is put a spring in the lower hose or get a radiator that is less flow restrictive.

 

You may be over driving the water pump also. A larger water pump pulley, turn the pump slower. ?

 

one complication seems to be mixing psia (absolute) vs psig (gauge). All my dozen or more gauges are psig . Some even are marked that way. Atmospheric pressure is ~ 14.7 psia and 0 psia

http://www.pumpfundamentals.com/images/mercury.jpg

 

[QUOTE="Dan Timberlake, post: 10640054, member: 112291" . . . All my dozen or more gauges are psig . Some even are marked that way. Atmospheric pressure is ~ 14.7 psia and 0 psiG[/QUOTE]

Minor correction...

Regarding psia and psig, since your gauge is in the air, it can only measure in relation to the air, that's psig. Measureing relative to the air on earth.

To measure psia, just put your car and gage in a vacuum chamber, and it will give you psia even if it says psig on the dial.

(If you can get the car to run in a vacuum. )

 

Pretty sure that's a just a simple typo

Atmospheric pressure is ~ (= to +/-) 14.7 psia and 0 psia should be psig.

Instead of entering a vacuum chamber to read a gauge or running cars in a vacuum chamber that big a better example - unless you'd need a time machine to see what time the clock said it was at noon yesterday ( see post 28 if that's unclear )

a bicycle tire pumped up to 65 psi on your tire gauge will have a pressure of
65 psig or
65 + 14.7 = 79.7 psia
Or
If the bicycle tire were flat, it would show 0 psig and 14.7ish psia.

However you could build a vacuum chamber to try I guess.

 

I agree with this -- if the cap cannot pull water back into the system from the overflow tank and the engine cools, it will create a vacuum in the engine. The soft hose will collapse.
Check the cap or try a new one.
Also won't hurt to be sure you have a small hole drilled in your thermostat.

 

I was being silly again.
Of course, only the gauge needs to be in the vacuum tank to read psia.

 

It's all very confusing with the gage and the absolute, the hot, the cold, but boiled all down it's as simple as I stated before - call it PSIG PSIA BAR - it's all relative - forget about it - it's just an offset.
You have a static starting pressure - atmosphere - pump on - pump output pressure RISES - pump inlet pressure DROPS. Inlet "pressure" is below atmospheric = a good start for a collapsed hose.

The radiator is a restriction - more restriction = more pressure to over come it. More pressure means more suction.

Outlet Inlet

Static:

Atmosphere_________________Atmosphere
________________/\_________________


Dynamic:



Atmosphere+_______________Atmosphere - (pretend this is tilted down)
_______________/\_________________

No free Lunch.

 

http://www.ebay.com/itm/66-72-Ponti...Parts_Accessories&hash=item2c798e4f65&vxp=mtr

Recently installed one in my car.

 

The confusion here is that all tests must be zeroed to what ever the atmospheric pressure is at what ever altitude you are at. 13 psi measured in the cooling system would be 13 psi over the atmospheric pressure. JW

 

Also water is classed as a solid and for the bottom hose to collapse, you will find that the top hose has expanded with the pressure created by the resistance for the coolant to flow from the water jackets and radiator core. It also amazes me that some folk can build a nice Hot Rod but cant bend a length of 1/8'' stainless wire around something to make a simple spring !!!!!! JW

 

Me too

 

Almost midnight here. JW

 

Hey, I want to thank everyone for their replies. I wasn't convinced that the proper solution to my collapsing lower radiator hose was inserting a spring in the hose. That might have solved the immediate issue, but I felt that was just masking the overall problem. It turns out (thanks Stimpy) that my radiator cap was not allowing for vacuum release in addition to pressure relief. Replacing the radiator cap solved my problem and no spring was necessary in the lower hose.