70454

I recently replaced my expansion tank, upper/lower radiator hoses, heater hoses on my 70 454. I filled the radiator so that the expansion tank was half full and I am now experiencing a hotter than normal engine. Could it be that the system is underfilled or overfilled? Could it be a thermostat issue? The car never had a heat issue and even ran fairly cool in hot temps. Now the fluid wants to steam from all fittings/hoses. Any suggestions?

Thanks.

Smokehouse69

You might have gotten some air in the system during the swap, and even though it looks full, it might not be. It's hard to tell when I system with a remote tank is really full.

R. Bruno

You need to get all the air out of the system. Run the car with the rad. cap off and fill the radiator until you are sure there is no air in the system. Also, check that your lower hose hasn't collapsed. Did the new hose have a spring in it?.

Steve Straus

I got a Gates, Napa, and Goodyear hose, and despite the fact that none of them fit quite right, they didn't have a spring.

I ordered a GM hose from Zip and not only did it fit perfectly, but it had a spring in it. The hose seems like a high quality piece as well.


jesus, what is this??? :party:

Larry B.

I do not know what you have in the way of hoses but... The correct upper hose is the one with a "U" shaped trap toward one end. A flex hose will NOT work and some aftermarket hose are missing the "U". The U must go down just in front of the alternator. IF there is any place in the system that is higher than the pressure cap, air cannot escape because air, being lighter than water will get trapped at the highest point and impede water flow (vapor lock if you will). Air at a point other than the pressure cap will aslo force water out when the pressure cap relieves or vents. Routing of the hose is very inportant. My gates hoses did not fit correctly either. ZIP hoses are exact.




[Modified by silvervetteman, 5:31 AM 1/27/2003]

70454

I bought all new hoses from Paragon. They are correct. I took the spring out of the old lower hose and fitted it into the new one. I don't have a hose collapse situation. I did not run the system without the cap on when I refilled it. I also didn't keep track of exactly how much fluid I added. When it runs for a short time it steams from the upper hose at the radiator and the hose going from the tank to the radiator. I will try running it with the cap off. When should I put the cap on? Is it a matter of time and heating the car up or should I look in the tank for a fluid level change?

Thank for your replies.

Matt

Solidlifters

I don't think you have an upper hose problem. The waterpump gets it's supply through the lower hose and pumps upward through the engine and would pump through any air in a high spot in an upper hose.. It's very easy not to get all the air out of the block on a refill with a sealed thermostat. I've been drilling about 4, 1/8" holes around the perimeter of the thermostat flange before installing for years and all those problems go away. An alternative is to remove the housing and thermostat and completely fill the block through that hole and re install the thermostat. Either way you've got full liquid in the area of the thermostat so that it can open properly when up to operating temp. Hot air doesn't open thermostats very well, especially higher temp thermostats. Drill the holes, or fill the block the other way and I'm pretty sure your problems will go away.

Bobchad

How is your overflow tank set up. Mine has a line that runs from the cap to the bottom of the tank. It has fallen off before I replaced it. This will allow coolant to blow out into the tank but won't allow it to be suctioned back in, which can actually increase the volume of air in your cooling system.

If yours attaches at the bottom then this shouldn't be a problem.

Bob


[Modified by Bobchad, 11:22 AM 1/27/2003]

PRNDL

Is your temp guage heading to the right, indicating overheating? If it is just steam or coolant coming from the connections you might only need to tighten up your hose clamps a bit. MJ


[Modified by MNJack, 11:56 AM 1/27/2003]

70454

Yes. Both. The guage is heading hotter and the hoses are steaming up a bit. I've got those hose clamps pretty tight. I've re-adjusted them to make the best contact and they still seem to be pushing steam.

Fevre

I am running rubber flex hose both upper and lower with no cooling problems.

Fevre

Did you happen to put the thermostat in upside down? A long shot but thought I would ask since it is allows the obvious with me. :bb

70454

No. I didn't replace the thermostat when I replaced the hoses.

Brettmc

I drained my rad this wkend to install Spals...no new hoses but a new thermostat...i finished yesterday but a leaky fuel inlet prevented me from warming the old gal up to test the fans...my plan was to leave cap off and look inside rad to be sure of adequate coolant flow from tubes then fill her up the rest of the way...sounds like it might not go as planned tho...I got a replacement fuel inlet at lunch today so I'll be testin my plan tonite...I'm very interested to see how this comes out for you, 70454.

Brett :thumbs:

70454

Brett:

I'll let you know. If I have time tonight (and if it's not 11 degrees again), I'll fire her up w/o the cap and see what happens.

Larry B.

I am running rubber flex hose both upper and lower with no cooling problems.
_______

Chris LeFevre

Small blocks are different. You cannot compare the big block set up. The block is taller and the accessory bracketing is unique. A flex hose that goes over the alternator will assure you of blowing coolant out of the surge tank (where the pressure cap is.. There is no cap on the radiator. AIR MUSTgo to the highest point.. hot air expands and pushes coolant out. More air replaces lost coolant... more air blows more coolant, etc.etc. No flame intended, just explaining my earlier post.




[Modified by silvervetteman, 9:02 PM 1/27/2003]