Is there a common coolant leak spot on passenger side rear of the motor?

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98EXPY 5-0

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Well I've got some kind of coolant leak somewhere. For a couple days I was smelling coolant occasionally with the heat on or off. Last night I could smell it on my way home and when I stopped at a closed gas station to use my credit card for gas, I shut the truck off. While pumping I saw steam coming from under the hood on the passenger side by the windshield. I popped the hood and got my flashlight. By then the steam had stopped. Nothing looked wet back by the firewall but I did see evidence of dripping on the ground directly under the firewall and maybe a little towards the rear. The passenger floor was dry. I tried to see where the heater core hoses went into the firewall, but I think what I was looking at was the air conditioner lines. I couldn't see anything wet or dripping, so I decided to drive the mile I still had to get home. I parked in front of my house and popped the hood and jumped out quick, hoping to catch some steam, but there wasn't any.

Other than the smell, it was running fine and my gauges never went out of their normal positions.

Is there a common leak point back there somewhere? I probably won't get a chance to look at it until this weekend, so it will just sit until then.
 

hwy73

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Heater Core is first guess, which could run out the a/c drain onto the ground, but the trucks with rear heat/air were known to develop a leak near the "T" fitting in the heater hoses which would drip on cylinder #4 cop and take it out.
 
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JUST4FUN

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look above the number 4 spark plug there is a hose that has coolant going through it thatis your leak
 
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98EXPY 5-0

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#4 is rear passenger side right?

Is this hosed fixed by replacing or tightening a clamp or something?

Would this cause the coolant odor in the cab?
 

Thermo

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98Expy, odds are, if you look on the firewall, you will see where the heater core hoses attach there. The connections are known to fail over time or from "abuse" during a plug change. I had this happen on my truck and I simply removed the hoses, cut the connectors off of the end and then slid the hose with a hose clamp back on to the nipple that was left. easy fix for me, but then, I had most of the top of the engine off at the time.
 
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98EXPY 5-0

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I found the two hoses with t-fittings (rear heat I presume). I tried squeezing the plastic wings that stick out to remove them, but it didn't come easy and I didn't want to break it if I was doing it wrong. How do these get removed.

I'm not even sure I could find the leak with them in my hand anyway. I guess I need to run it up to temp and look for the leak. I don't have any other way to pressurize the system to force fluid out of wherever the leak is.

Also, are these lines a dealer only part? I tried looking for them online without much luck, to see what it would cost to just replace both.
 
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98EXPY 5-0

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Well I rented the coolant pressure tester over the weekend. Only to realize that I don't have a radiator cap and there was not an adapter for the cap on the expansion canister. In fact, the kit might just be useless. I tried it on my wife's suburban and all it did was blow bubbles in the overflow jug.

Neither one of the T fittings is over top of my COPs. They are both between the battery and the valve cover. I didn't start the motor to let it warm up and spray again. I didn't feel comfortable spraying coolant on the street in front of the house.

I also had the guy at Autozone check and he only has the straight heater hoses, not the T-fitting ones for rear heat. He said that rear heat wasn't even an option given when putting my vehicle info in. So are these hoses DEALER ONLY?

Also, that little plastic clip doesn't seem like it would be enough to hold the pressure from the system.
 

hwy73

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There is a tool that looks like an "L"-shaped, 2-prong fork that slides over those firewall fittings which releases the clips and provides a way to pull the hoses off. If you look on the beginning part of this video (2:40)
F150 Heater Core part 1 - YouTube
you will see the fellow do it. No "T" fittings, as he is working on an F-150. Then in part 3 when he is doing reassembly he does the rebuild kits for the fittings.
 
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98EXPY 5-0

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I guess I need to find one of these tools. I cut the old lines to get them out of the way. I can only get my hand on the left line on the firewall and it's not popping off. I can't even get my hand on the right side one until the left is off. I'm afraid to put too much pressure on it because I don't want to break the heater core hard line.
 

Big White

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Well I rented the coolant pressure tester over the weekend. Only to realize that I don't have a radiator cap and there was not an adapter for the cap on the expansion canister. In fact, the kit might just be useless. I tried it on my wife's suburban and all it did was blow bubbles in the overflow jug.

Neither one of the T fittings is over top of my COPs. They are both between the battery and the valve cover. I didn't start the motor to let it warm up and spray again. I didn't feel comfortable spraying coolant on the street in front of the house.

I also had the guy at Autozone check and he only has the straight heater hoses, not the T-fitting ones for rear heat. He said that rear heat wasn't even an option given when putting my vehicle info in. So are these hoses DEALER ONLY?

Also, that little plastic clip doesn't seem like it would be enough to hold the pressure from the system.

I got the same tool from pep boys. Had to go back after getting home and get the "screw adapters" so that I could attach it to the de-gas tank (coolant reservoir). I thought I had a head gasket leak only to find out my cap was the leak. Win for me.
 
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