2007 Yukon..Common places to check for coolant leak.

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Hi,

2007 Yukon XL dropping coolant on to my drive after average driving conditions. Any advice on where to look, the pool on the ground is just inside the nearside front wheel.

Thanks in advance
 

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"Nearside" meaning passenger side? The plastic Ts in the heater hoses near the passenger side firewall crack and leak. Put some toilet paper or a paper towel around them if a leak is not evident upon visual inspection.

If one or both are leaking, it's strongly recommended to replace both with AC Delco, not Dorman Ts which are know for a short life.
 

OR VietVet

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I am assuming you are talking about the driver's side when you say "nearside"? Do you mean inside at the front or rear area? Front area could be driver's side of the radiator or radiator hose. Have you pressure tested to get it to leak faster and do a sight check? Many areas around the engine area can leak and drain down and drop to the ground away from where the actual leak is at.

I honestly, in all my years in this industry, never heard the nearside as a description of a side of vehicle. Drivers side=left side and passenger side=right side.
 

Fless

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I am assuming you are talking about the driver's side when you say "nearside"? Do you mean inside at the front or rear area? Front area could be driver's side of the radiator or radiator hose. Have you pressure tested to get it to leak faster and do a sight check? Many areas around the engine area can leak and drain down and drop to the ground away from where the actual leak is at.

I honestly, in all my years in this industry, never heard the nearside as a description of a side of vehicle. Drivers side=left side and passenger side=right side.

I hadn't, either, but I've never been to England.

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And I've never been to Spain, whatever that has to do with this. I HAVE tried to sleep through a 3 dog night, though. LOL

 
OP
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"Nearside" meaning passenger side? The plastic Ts in the heater hoses near the passenger side firewall crack and leak. Put some toilet paper or a paper towel around them if a leak is not evident upon visual inspection.

If one or both are leaking, it's strongly recommended to replace both with AC Delco, not Dorman Ts which are know for a short life.
yes passenger side, thanks for the advices will check those.
 
OP
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I am assuming you are talking about the driver's side when you say "nearside"? Do you mean inside at the front or rear area? Front area could be driver's side of the radiator or radiator hose. Have you pressure tested to get it to leak faster and do a sight check? Many areas around the engine area can leak and drain down and drop to the ground away from where the actual leak is at.

I honestly, in all my years in this industry, never heard the nearside as a description of a side of vehicle. Drivers side=left side and passenger side=right side.
thanks, will check out how to do a pressure test and yes, passenger side.
 

Doubeleive

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get a flashlight and get under the truck.
check bottom of the radiator
check under the water pump
check hoses that connect to water pump including the plastic T to the reservoir tank/heater
check the reservoir tank
check the 2 heater hoses that go into the firewall (passenger side) those also both have a T (these are very typical to break or crack over time)
check down both left & right side of radiator from the top
if you still can't find the leak, then leave a large piece of cardboard under the suspect area overnight and look at it in the morning (before you start or move the vehicle), look at the wet spot and directly above it will likely be your source.
you will not have any coolant leak on the driver side unless it is the radiator at the front.
 

petethepug

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The plastic on the radiator tanks likes to stress crack. After the hot coolant stops circulating in the system from the engine off you can follow the trail. Another method is to turn the a/c on full blast and as many electrical accessories as possible and the pressure / temp increase from the load on a hot day will reveal the source of the leak. On our 08 Denali it was two cracked radiator side tanks and a crack in the coolant overflow.
 
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get a flashlight and get under the truck.
check bottom of the radiator
check under the water pump
check hoses that connect to water pump including the plastic T to the reservoir tank/heater
check the reservoir tank
check the 2 heater hoses that go into the firewall (passenger side) those also both have a T (these are very typical to break or crack over time)
check down both left & right side of radiator from the top
if you still can't find the leak, then leave a large piece of cardboard under the suspect area overnight and look at it in the morning (before you start or move the vehicle), look at the wet spot and directly above it will likely be your source.
you will not have any coolant leak on the driver side unless it is the radiator at the front.
thanks, these are very helpful ideas. Changed the Firewall hoses 2 years back, hopefully they have not gone again
 
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Looks like it's the heater hose, leaking under the Y connector near the engine block. Got a Dorman replacement with a steel Y connector, hopefully this should be pretty durable.
 

DBacon

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My 2007 leaked along the rear heater lines, aluminum tubes tightly clamped every couple feet to the rocker panel. Leaked at a couple clamped areas. Rather than redesign that method of mounting the hoses, I just capped them off. BTW the AC tubing was already capped off... Many stories on the web about these leaking, I think they should have considered the expansion of the lines when mounting them, you can't fight it!
 
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