Hey boys/gals...

Techy question.

I just had the coolant changed by Ford.

Now 3 or 4 times, after the car is off...I see a puddle of coolant underneath the car. It looks to be leaking from the resevoir cap itself bleeding out.

What could be the cause?
The car is not overheating and the resvoir is down to 1/5 when the car is off.

Help!

 

Maybe the system needs to be re-bled?

 

Stinger mentioned this to me.

Running it without the cap for 10 min
Hopefully that's all it is.

 

Might be just overfilled. There should be a little level indicator somewhere on the reservoir. If its over the indicator, it may not have enough room for expansion and let the excess out. The pressurized reservoir will only hold a level to the full line.

 

I believe it's more complicated than this. There should be a high point bleed screw. I am not sure if the reservoir is the highest point in the cooling system. Supposed to relieve the air with the cap tight and from the screw. Snap a pic of your engine bay just to make sure I'm on the same page though.

 

Right - its not like the old days.

The Dealer should do it since they refilled it. Prob takes once or twice after a new change to get excess air bubbles out.

 

http://www.allfordmustangs.com/forum...96-post13.html

That the valve/screw?

 

No.

And I thought there was a bleed screw like Al said (I looked but its my Chrysler that has the bleed screw). Sorry.
The Ford manual (08 Mustang) says Ford has a "RADKITPLUS #078-00497" and follow it's instructions. lol

Or it explains to do it the old fashioned way (guess its not pressurized). (08 Mustang 4.6L, section 303-03A-23).

*Fill coolant/distilled water between the marks on the degas bottle.
*Select the max heater temp & max blower speed settings and position control to send air through the AC vents. (to flush the heater core also).
*Start engine and idle until normal temp is reached. Hot air should be coming out of the AC vents. The top hose should feel hot. The temp guage should be remaining in the the middle of Normal range.
*Shut engine off and allow to cool completely.
*Check the level in the degas bottle and fill as necessary through the cap.

When I do this on my old F150 I do it with the cap off (takes longer to come up to temp this way). But the manual does not say either way for the Mustang so I assume have the cap on and let any excess escape through the overflow hose.

Hope this helps.

 

I believe that you fill the coolant system from that plug. Then fill the reservoir to the fill line and cap it. Don't touch the reservoir cap again. Only fill it from the plug after that. That's the way it is on my car for sure. For mine which is very tricky to bleed and fill, I sealed a funnel to the plug opening. Reservoir already full line and capped. Just squeezed the upper and lower hoses till there were no more air bubbles present. Cranked it up just to top off and it was ready to go.

 

Apparently some have a "degas bottle" (pressure release cap on bottle - no radiator cap). Others have a "coolant expansion tank" have the pressure relief cap on the radiator (08 Mustang 4.6L, section 303-03A-5). My 08 has the cap on the bottle.



I looked again - my 08 does not have that screw atop the thermostat housing. Nor is it shown in the exploded view in the manual for the thermostat (08 Mustang 4.6L, section 303-03A-28).

 

I have the pressure cap + screw.

I got some gold coolant/deonized water tonight. And ran it.
Fans working...coolant circulating. Heat enough to cook an egg off the vents... **** its hot out lately.

I noticed bubbles swirling in the coolant res. for a bit.
After the 10 minute mark I noticed it was bubble free and wasn't rising anymore.

I'll check it tomorrow morning to see where it settled.

 

I went through the same rigamarole - turned out it was the thermostat the whole time... so much $ on distilled water down the drain... pun intended.