Upper radiator hose rock hard????

Discussion in 'Fox 5.0 Mustang Tech' started by tbird187, Mar 7, 2004.

  1. After I let my car warm up all the way and drive it. I notice the upper radiator hose is rock hard seems there is to much pressure in it. Is it supposed ot be like this? How can i fix it ...
  2. Have you checked the radiator or resevoir cap on the system? They are basically relief valves which are designed to vent and release pressure when it gets too high. If yours isn't working properly, in theory it could allow system pressures to get too high. If yours hasn't been replaced recently, they're fairly inexpensive. Might be worth replacing the cap (get the proper one - different cars have different system pressure requirements) to see what that does to the situation. Are you having any other symptoms? Maybe it's not worth worrying about....
  3. no other symptoms I put a new cap on 16lbs one. I only have a tube off the overflow no tank....
  4. Is 16lbs the proper spec for the system? If so, and there are no other symptoms, drive the car!! Mine is spec'd much lower - 7.5 psi.
  5. The upper hose should be pretty hard anytime after the thermostat opens. If your cap is the right one then it should vent before anything happens. I probably woudlnt worry about it
  6. just a thought

    Have you ever had it off of the car to look inside it?

    when I took my car apart last year for the motor rebuild, my lower radiator hose was hard as a rock, come to find out there was a spring inside of it, I guess to keep it from collapsing maybe. I have never heard of this being the case on upper hoses, but just something for thought.

    I would say, if you have the appropriate cap on the radiator you should be okay.

    Have you changed a t stat or anything lately, maybe theres some air in the system. If you think it would help you could try burping the system.
  7. ...my upper has a spring in it too...
  8. no spring in my upper hose..... how do i find out what my pressure for the cap should be?
  9. most systems for small blocks use a 13-15 lb. pressure cap-if your system is tight, no leaks, then it is normal for the upper hose to be hard when the system is up to operating pressure. when it is not hard, then either the pressure cap is leaking or there is another leak somewhere else that prevents the pressure from building up like it should. the system operates under pressure in order to increase the boiling temperature of the coolant to make the system more efficient at keeping the motor cool. lower hoses often have springs in them to keep the water pump from sucking it flat and then not pumping properly causing the motor to overheat. good shops have a pressure tester that can check both caps and the cooling system under pressure if you really are worried about this, but I think it is normal and wouldn't lose any sleep over it as long as the temperature is normal range.