Found another coolant leak - heater core (Page 3/4)
Cliff Pennock OCT 02, 11:43 AM
So armed with a 1/2" copper pipe, a pipe cutter and some knee joints, I tried to temporary fix the car. Turned out it wasn't 1/2" but 3/4"... 😭

But, I also saw this is probably going to be the easiest repair I ever did on my Fiero so I decided to wait for the heater core to arrive (which according to the Fedex website will be Wednesday) and just replace the heater core where the car is now.

One thing did surprise me however. When I took of the (insert name of that thing that runs along the length of your front window), and got a clear view of the hoses, I saw this:



What the heck is this? Who put that in an what for? It says "Keep tight. Flush Fill Connector"
Vintage-Nut OCT 02, 12:18 PM
As the cap says, this a coolant flush connector.

The complexity of the Fiero coolant flush (draining and filling) procedure in the manual by cleaning out ALL the old coolant requires several flushing’s until the drained liquid is nearly colorless.

But some people will use 'this' fitting (like on your car) is an 'easier' way to flush the Fiero coolant system. A person can now flush the coolant by connecting a hose (clean water) and opening the coolant system (radiator drain) with the engine running.

But to me, it is a 'bad' idea as 'tap' water can contains high levels of dissolved minerals; I ALWAYS use distilled water to flush my coolant systems.

EDIT: Inspect your coolant system and check for another 'cap' to open the system as this person who installed the coolant flush fitting, maybe installed another 'drain' too.

IMHO (which means that some members want to argue about MY views)

Below is MY V6 Coolant Draining Procedure:
-------------------------------------------------------------
*DO NOT try to open the plastic radiator drain valve; the plastic stem often breaks, or the threads get galled. Leave the plastic radiator drain valve alone.

*I don't try to open the two drain plugs built into the coolant pipes under the car as these plugs are normally very tight (frozen) and their inter socket of these plugs will strip.

*I don’t waste any time on the V6 engine block drain plugs either as aren’t accessible (one is under the starter) and ineffective as considerable amounts of coolant can remain in the block. (BTW: Some members will remove the starter and will attempt to flush the block.)

The passenger coolant pipe under the car, and 3-inches rearward more from the drain plug; remove the rubber hose (heater core) from the main pipe to start draining the coolant. Leave the radiator and engine/thermostat caps on. After the coolant drained; open the caps and remove the thermostat.

Without the Thermostat:
*Install the rubber hose (heater core) back on the main coolant pipe
*From the Thermostat Housing; pour distilled water watching the radiator opening, when fill, cap it
*Pour distilled water to fill the thermostat housing, and then cap it enough to seal the housing
*Run the engine 30 seconds, shut it off, open the engine cap, add distilled water and cap it tightly
*Run the engine at least 10 minutes to circulate the liquid, and then shut it off to cool it down

*Drain it again and fill it up repeatedly until the drained liquid is very clear. (On my GT is around ten times)

Install the rubber hose (heater core) back on the main coolant pipe.
Remove the coolant recovery tank, clean it and reinstall it.

Filling Procedure:
Keep in mind, the cooling system fluid capacity is 13.8 quarts and the fully flushed coolant system has ~7 quarts of Distilled Water in the engine block. The next step is to pour ~2 gallons (8 quarts) of straight full strength concentrate antifreeze, not a premixed 50/50.

------------------
Original Owner of a Silver '88 GT
Under 'Production Refurbishment' @ 136k Miles

[This message has been edited by Vintage-Nut (edited 10-02-2023).]

theogre OCT 02, 06:17 PM

quote
Originally posted by Cliff Pennock:
CLICK FOR FULL SIZE


What the heck is this? Who put that in an what for? It says "Keep tight. Flush Fill Connector"

is version of Prestone® Flush ‘N Fill Kit https://prestone.com/produc...ne-flush-n-fill-kit/

And been on there for Decades & can leak or break if you mess w/ it now.

I & many others hate them because they break often w/o warning. Often don't work very well either.
+ maybe Illegal in some places as users often dump coolant on the ground, in sewers, etc.

[This message has been edited by theogre (edited 10-02-2023).]

Patrick OCT 02, 06:33 PM

quote
Originally posted by Cliff Pennock:

One thing did surprise me however. When I took of the (insert name of that thing that runs along the length of your front window), and got a clear view of the hoses...



I don't know what it's called either, but are you referring to the tray/support that holds the sunroof while stowed up front?
Cliff Pennock OCT 03, 01:37 AM

quote
Originally posted by Patrick:

I don't know what it's called either, but are you referring to the tray/support that holds the sunroof while stowed up front?



Yes!
Patrick OCT 03, 02:41 AM

quote
Originally posted by Cliff Pennock:

Yes!



Yep... when that's removed (whatever it's called ), it really opens up access.
A_Lonely_Potato OCT 03, 08:26 PM
front tub cowl? best i can come up with for it.
Patrick OCT 03, 09:01 PM

quote
Originally posted by A_Lonely_Potato:

front tub cowl?



Except that non-sunroof Fieros don't have it (or the two small supports for the sunroof at the front of the tub).
Cliff Pennock OCT 04, 01:56 AM
I looked it up. Apparently it's called the "Shroud Top Vent Screen". 😁
Cliff Pennock OCT 04, 02:20 AM
No wait, it's called the "Glass Roof Vent Storage Cover".