Turbo Dodge Forums banner

1 - 19 of 19 Posts

·
Registered
Joined
·
114 Posts
Discussion Starter #1
Refilling cooling system today.
1990 2.5L -
Above the thermostat on the "water box" there is a fitting(vent) I need to remove before refilling coolant.
WHAT TOOL FITS IT?
is it hex?????
thanks
Scott
 

·
Registered
Joined
·
3,340 Posts
It was hex originally. I'm guessing you are asking because it isn't hex anymore? Do you know about drilling the 1/16" hole in the thermostat?
 

·
Administrator
Joined
·
24,827 Posts
It is a 5/16 Hex.
That plug is still available thru Mopar as it is still used on the Jeep 3.7L and 4.7L
The part # is 6034331.
It is still a good idea to remove the plug when draining as this will allow the block and heater core to drain completly.If you cannot remove the plug then you can accomplish the same thing by removing the coolant temp sensor.
 

·
Registered
Joined
·
114 Posts
Discussion Starter #4
I didnt know bout the 1/16 hole in stat.
Now, I do!
Ok, it is a hex, thanks for the size too.
I have a metric set that didnt quite fit properly. now-I know why.
So I will remove temp sensor...IF I need to.
Ive already filler radiator and through several warm/cool cycles its drinking in coolant.Ive got heat, all hoses are hot, should I remove temp sensor anyways?
do I have to?
 

·
Registered
Joined
·
584 Posts
It is a 5/16 Hex.
That plug is still available thru Mopar as it is still used on the Jeep 3.7L and 4.7L
The part # is 6034331.
It is still a good idea to remove the plug when draining as this will allow the block and heater core to drain completly.If you cannot remove the plug then you can accomplish the same thing by removing the coolant temp sensor.
I can't get my plug out. I have soaked it for several days with liquid wrench and still nothing. I guess will have to remove the sensor. So how does removing the coolant temp sensor do the same thing as removing that plug?
 

·
Premium Member
Joined
·
9,043 Posts
they will both serve to 'vent' the 'water box' - whether you are trying to drain all coolant out, or 'burp' out any air which may be in there

when filling (burping) - I have best luck by parking the car on a slight incline such that the nose is high, then let car warm up with rad cap off; keep adding coolant until it starts to swell back out, then cap it quick

may need to repeat this a couple times to get the system fully air-purged

make sure you have coolant in your overflow bottle too
 

·
Registered
Joined
·
2,134 Posts
I would NEVER remove that plug. Tried it once, and ended up having a broken easy out.

Much easier just drill a hole in the thermostat.

DDG- Tricks for going fast!

agreed, that thing it usually a b*tch to remove...fought with it for several hours when i did the headgasket in my lebaron. with the head off and heat and lots of PB still nothing, had the machine shop take it out and i put a new one in, with a generous helping of anti seize.
 

·
Administrator
Joined
·
24,827 Posts
The CTS is located in the head behind the thermostat so if you remove it when draining it will allow air to enter and the block to completly drain.The only fallback is that it sits slightly lower than the hex plug so when filling you will need to keep your finger slightly over the hole so you do not lose a lot of coolant and when it is filled to the top of the hole quickly reinstall the CTS.
I avoided the stuck plug situation by replacing it every 2 years when i do the thermostat and drain and refill.It is worth the $3.00 investment and I keep extra's at home.
 

·
Premium Member
Joined
·
9,043 Posts
If I dont care about a FULL drain, heater core etc do I NEED to vent the system???
Thanks!
if theres much air in your coolant you will see things like temp gauge spiking up and down, heat from heater core being sporadic...

after you do a head job or other job where you have drained all the coolant = just keep your rad full by checking it every couple days ; eventually you will get all the air out
 

·
Administrator
Joined
·
24,827 Posts
Draining completly and refilling with new coolant is always a good idea.The additive packages in the coolant become less effective over time and the ability to transfer heat,lubricate the water pump,and protect disimilar metals against corrosion and deposit buildup will suffer if left in too long or new is added to old.
FYI, Mopar RED lifetime coolant is NOT the same as Gm's Dexcool.I asked this question at training and was told they are completly different and they are NOT compatible.
 

·
Registered
Joined
·
13,463 Posts
I avoided the stuck plug situation by replacing it every 2 years when i do the thermostat and drain and refill.It is worth the $3.00 investment and I keep extra's at home.

You do real that maybe 1-3 % of the original owner who bought their 80-90 dodges still have their car, right? And if the plug hasn't been out since new, it's not going to come out without a fight. Much simpler just to drill a 1/16 hole in the thermostat to make the system self bleed.
 

·
Administrator
Joined
·
24,827 Posts
Yes I do realize that but for those that have been able to get the plug out and are not in the situation of it being siezed replacing it when you do cooling system work is a good idea and a minimal expense,you never know when you may have to remove it.
 

·
Registered
Joined
·
2,134 Posts
replacing it when you do cooling system work is a good idea and a minimal expense,you never know when you may have to remove it.
agreed, when i put the new one in my head, i bought a bunch (like 5) from work, for that exact reason.
 

·
Registered
Joined
·
2,134 Posts
uhhh, no..lol.
 

·
Administrator
Joined
·
24,827 Posts
I am confused,I am not sure what your response means.
 

·
Registered
Joined
·
2,134 Posts
I work for advance auto parts. i bought a bunch of the plugs for the bleed hole at the same time when i replaced mine.
 
1 - 19 of 19 Posts
Top