I think I just blew my OTHER heater hose (coolant diagram?)

[AlphaAssault]

Months ago I had to replace the heater-core hose that ran to the top of the coolant system right next to the radiator cap. Recently, I am leaking coolant from somewhere on the passenger side of the car, and I cant find exactly where. My guess would be the lower heater hose; but i cant be sure for a few reasons:

1) the coolant is leaking onto the transmission before hitting the ground. most of the coolant is leaking down from the backside of the tranny, but some is leaking down from the front as well. i looked and it didnt look like either heater hose was positioned in a way that would leak coolant so that it would dribble both ways on the tranny.

2) secondly, both heater hoses appeared to be fine; though i cant be sure because it was dark out and i was only using a flashlight. my primary question here is if there are any more lines back around the thermostat housing/rear passenger corner of the engine in which coolant flows, besides the heater hoses. a diagram would sure be nice, if anyones got one. also, assuming it is the lower radiator hose than requires attention, how much coolant am i looking at losing when i undo that hose?

 

[motorboat]

if you undo your lower radiator hose you will lose all your coolant, so have a bucket ready. If you think your heater core hoses might be bad it would be safest to replace both of them, coolant isnt a nice fluid to animals. There is a coolant line that runs to your throttle body, most people dont have it anymore. Just check all the hoses that run from your thermostat housing and from your water pipe.

 

[BUCK]

You need to replace EVERY old original Coolant Hose on your car - 1 Gallon of Antifreeze will service the entire System - Why not replace Thermostat & Flush your Radiator, Motor & Heater Core while you are at it?

 

[DGajre777]

You probably blew the turbo water return line.

Turn your car on, let it heat up to normal operating temperature and then shut it off. With your car off squeeze the upper radiator hose, you'll see coolant come off from the hose that is leaking.

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10163P, 10163Q and 10164 - Engine Oil Cooler
10719 - Turbo Water Return
10718 - Turbo Water Feed
10712 - Throttle Body Water Return
10711 - Throttle Body Water Feed

 

[AlphaAssault]

You need to replace EVERY old original Coolant Hose on your car - 1 Gallon of Antifreeze will service the entire System - Why not replace Thermostat & Flush your Radiator, Motor & Heater Core while you are at it?

the system has been flushed numerous times, even since ive owned the vehicle.

You probably blew the turbo water return line.

Turn your car on, let it heat up to normal operating temperature and then shut it off. With your car off squeeze the upper radiator hose, you'll see coolant come off from the hose that is leaking.

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10163P, 10163Q and 10164 - Engine Oil Cooler
10719 - Turbo Water Return
10718 - Turbo Water Feed
10712 - Throttle Body Water Return
10711 - Throttle Body Water Feed

I dont think the leak is that far up; the majority of the coolant appears to have come from the back passenger side of the engine, with just a bit dribbling down from the front end of the transmission. The water return line is metal though, isnt it?

as of right now, im still trying to pinpoint where the leak is. i have been out there numerous times, and cant find a hole in either of the heater hoses. you say theres a coolant hose that goes to the throttle body, where exactly is that hose? because it might have blown a hole, but i dont know where it is.

 

[AlphaAssault]

sorry for the double post, but ive found the source of the leak. its not a heater hose, but a smaller hose coming off the back of the thermostat housing. it comes off the housing just above the heater hose. does anyone know what the name of this tube it, where it goes to, and the internal diameter? im completely lost because i have no idea what that coolant hose is for.

 

[DGajre777]

sorry for the double post, but ive found the source of the leak. its not a heater hose, but a smaller hose coming off the back of the thermostat housing. it comes off the housing just above the heater hose. does anyone know what the name of this tube it, where it goes to, and the internal diameter? im completely lost because i have no idea what that coolant hose is for.

Throttle body water line. Run a 3/8" fuel line and you'll be set.

 

[AlphaAssault]

Throttle body water line. Run a 3/8" fuel line and you'll be set.

is it 3/8 even on a 1990?

 

[Black91TSiAWD]

is it 3/8 even on a 1990?

sure is, just did some last week on my 90.