So after seeing a leak and rust in my 3.0 ranger i repaced radiator, thermostat, all the hoses including both heater hoses, and stant 16 psi rad cap. I still have upper rad hose calapsing and a lot of pressure spewing out water when i take the cap off??? What can i do to correct this?

 

Make sure you get all the air out of the system.

 

Im pretty sure i did that but want to change tgermostat to one rated 195° i think i might have put a 180° one in....everything i researched says i should have a 195°??? Is that correct? Also what psi cap should i have? Want to make sure i have everything correct

 

Should be a 192-195 thermostat and a 16psi cap

 

+1 ^^^

Make sure new thermostat has a "jiggle valve", it is a hole in the plate with a metal pin in it, it allows air out when refilling the system, hole should be at 12:00 position when installed(where the air would be, lol).

Best way to fill up cooling system is to unhook a Heater hose at by-pass or firewall which ever is the highest point, and then fill system until coolant is coming out that hose, this allows air to escape from engine.

Cooling system has no internal pressure when cold, you can start up engine with rad cap off and no coolant should come out of the radiator, if it does then you have a head gasket leak.
You can get a burp of coolant out of the rad from air trapped inside but it should not continue to overflow.
Search this site for: Glove test
If you think you have a head gasket issue, free and easy test for that.
Water pump is not a "pump" it just circulates coolant, it adds no pressure.

The pressure in the system comes when coolant is heated up, it expands in volume, laws of physics.
The rad cap holds that pressure in because that raises the boiling point of the coolant.
Water boils at 212degF
50/50 coolant and water boils at 230degF
But if you add 15psi of pressure then 50/50 boils at 260degF, about 2degF increase per 1psi
Normal(best) operating temp of gas engine is when coolant is at 200-220degF, Ford temp gauge on dash has approx. 220 as center line, so normally needle would be just below center after full warm up.
When going up a long grade or pulling a heavy load it might run up to center or just above, 220-230degF.

As coolant expands the pressure in cooling system will reach 16psi and ONE of the valves in the rad cap will open and allow the "extra coolant" to flow into the Overflow tank via overflow hose.
As engine cools down then the OTHER valve in the rad cap allows coolant to be pulled back into the rad from the overflow tank.

A collapsing Upper or lower rad hose means the "other valve" or overflow tank is not allowing coolant to flow back in so there is negative pressure in cooling system.

If cap is new then check overflow tank, it can get debris inside and coolant can flow in, pushing the debris out of the way, but debris will block coolant flowing back out of the tank.


So you shouldn't have pressure in cooling system until engine is warmed up, period, and you should never take rad cap off if engine IS warmed up.

 

Okay i have a new 195° thermostat with air relief valve n new 16 lb rad cap...my only question when refilling system with heater hose disconnected....do i do that with the engine off

 

Yes, engine off

You don't need to ever fill with engine running.

Any air left in the system will eventually make it's way to the top of the rad, when engine warms up and coolant expands the air will be pushed out first, and into the overflow tank where it will bubble up to the surface.
When engine cools down again only coolant will be pulled back in.

So the system is self purging

 

New thermostat and rad cap is in and everything seems good. Thanks for all the help! I have bee running a radiator flush for a couple of hours and it has produced quite a bit of sludge at neck of radiator. What is the best procedure to flush the whole system and refill???

 

Wait for system to cool down.

Remove rad cap
Remove upper rad hose(rad end), allows floating junk out
Put garden hose in rad cap opening with low pressure to clear all the floating stuff.

Remove lower radiator hose(rad end) and allow all water to drain
Put garden hose in rad cap opening and turn it on.
Put hand over lower rad opening until water comes out upper opening(rad is full) remove hand, repeat.

Disconnect both heater hoses at firewall, mark one so you know where it goes.
Put garden hose on one heater core fitting to flush core
Switch to other fitting, back flush
Make sure both directions flow the same.
Put garden hose on heater hose to flush engine
Switch to other hose
If you have heat control valve or by-pass valve on heater hoses then mark hoses and remove so you can flush engine.

Let system drain and then start putting hoses back on, leave 1 heater hose disconnected.

Remove overflow hose from rad pull it out so end is lower than BOTTOM of Overflow tank, put garden hose in tank and fill so water comes out hose, remove garden hose and make sure tank drains completely, it should siphon out competely if it isn't clogged.
refill and let it drain again, you want to make sure there is no debris left in the tank to clog it up.
Reattach over flow hose.

I have used a Bottle brush to clean out the inside of overflow tanks, they can get coated inside so you can't see level of coolant inside.

Refill system with 50/50 coolant until coolant comes out heater hose, reconnect heater hose, top up rad.
Put coolant in overflow tank up to the COLD line on the tank

Start engine, coolant level in rad should drop, top it up and put on rad cap.
Turn on Heater to HOT, fan doesn't need to be on.
Let engine run for 1 minute then shut it off, spin radiator fan manually, it should spin easily, you are testing Fan Clutch.
Restart engine and let it warm up to normal, take it out for a drive and make sure heater is blowing hot.
Shut off engine and check coolant level in OVERFLOW tank, not rad, it should be above COLD mark.
Try to spin fan again, it should move but is stiff, won't spin freely, Fan Clutch is OK.
Let engine cool off and level in tank should go down to below COLD mark, air is purged, top up OVERFLOW tank to COLD line, not rad.

Check overflow tank over the next few drive cycles, check when engine is cold, add coolant to overflow tank if it is below COLD line

 

RonD's post should be stickied in a general maintenance section.