428 over pressurized expansion tankOctober 7 2017 at 11:22 AM
|Jon (Login saltshakerxxl)|
Fresh rebuilt 428 and it has kicked the radiator hose off the radiator... it had been filled with water and a 10lb cap. I was able to get a 5 gal bucket of water from a restaurant, reattached the hose and filled the tank....all was good. Took the car on a 150 mile ride 70 deg outside no issues. Yesterday took the car out for fuel it was 84 out again no issues. This morning there was water under the car, backed it out the garage and went to take the radiator cap off and the expansion tank was pressurized...water was pouring out! I rented a pressure tester and after refilling the tank the system held 15lb for 10 plus min...I been using a 160 deg thermostat....
Going to replace the thermostat, cap and fill with 50/50 antifreeze... any thoughts what might be going on? The car has always run cool, even in 100deg summer heat!
|October 7 2017, 12:01 PM |
old stuff like that always run minimum 50/50 coolant 70/30 my fav is using green coolant
But a car like that the EVANS coolant is the only option for coolant. way to many advantages
and less bugs to work out at the end of the year. still have 3 vehicles all have had the same
coolant since 2004 great stuff.
Evans coolant would not of kicked off your hose even with a 30 psi cap cause if you lucky it will make 7 psi
max, but never seen it on all 3 cars have mine in, 3 psi caps all that is needed.
Anyway your tank may have burped out the water little by little during the drive and after it was parked, the tank is not coolant catch, it purges the water out the vent tube.
just have to keep an eye on it, it will operate at a certain level of coolant in the tank at operating temperature. once you find it that is where you keep it.
always check coolant and oil in the mornings before cold start.
|This message has been edited by Ranchopower on Oct 7, 2017 12:08 PM|
Are you sure there's no air in the system?
|October 7 2017, 1:23 PM |
Using the old surge tanks , you need to either fill the tank reeeal sloooow. Or, as iv;e heard of others doing, raise the front of the vehicle up high enough that it flows in smoothly. I solved that air lock problem in my sons 63 Galaxie by drilling a 1/8" hole ln the thermostat. It fills with no problems now.
Re: Are you sure there's no air in the system?
|October 7 2017, 1:36 PM |
I will drill a hole in the new thermostat.. why would having air in the system pressurize it?
|This message has been edited by saltshakerxxl on Oct 7, 2017 1:53 PM|
(Select Login johnvermeersch501)
FWIW....the heater plays a part in thermo bypass...
|October 7 2017, 2:07 PM |
Quite often we see the heater hooked up backwards which can cause an air lock, disrupting water flow....the upper hose (water OUT of the engine) needs to hook to the LOWER heater tube (all Fords have an upper & lower tube). This fills the core from the bottom preventing air bubbles which can stop flow....
|October 7 2017, 2:09 PM |
The car is a replica 427 Cobra
|October 7 2017, 2:13 PM |
you mentioned you used only water during a road trip correct?
|October 7 2017, 2:21 PM |
it steamed out during the trip
|October 7 2017, 2:41 PM |
using water makes steam and it never last long in a healthy engine. steam train whoo hooo!
|October 7 2017, 2:49 PM |
you just over filled it. when cold you only need to cover the bottom of the tank maybe 3/4 of an inch. Doubt you are getting compression in the system as it would lose pressure over night & fill a cyl. If you have a tight system it will retain pressure over night especially if the tank was filled to the top. I'm always amazed when I relieve the pressure on mine when it's hot, the expansion tank deflates like a balloon. Your coolant needs a place to go when it is hot and expands, if you had it full to the top of the tank, that's why it blew the hose off.
One more question
|October 8 2017, 12:07 PM |
The hose from the expansion tank goes to the port at the top of the radiator tank?
|October 8 2017, 6:27 PM |