Coolant leak help. Common external points of failure?

[Charlie207]

2014 5.3 stock engine with Blackbear tune.

Not sure how long it's been losing coolant, as I work from home and don't drive much. This past weekend I noticed hotter than normal temps, and no heat in Park (vehicle stopped). I checked the coolant level and it was low - reservoir was almost empty. (f$ck).

Added coolant when engine was cold up to the fill line (sat overnight on level ground), and went for a drive to get up to temp & run some errands. Checked next day and reservoir was down 1/2"-3/4".

I can't see anything dripping when the car is parked w/engine ON or OFF.

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SCRATCH THAT.... I just went out to check in the daylight, and DO see coolant leaking out from under the reservoir/expansion tank. And the level looked lower than it did the last time I checked (engine was cold and had not run in between checking).

Checking prices/availability for local pickup of new overflow tank. wish me luck, gents.

 

[Geotrash]

My 2c: Check your coolant tees by the firewall. And check around the radiator thoroughly, as well as the water pump shaft. Check also to see that there are no hoses with worm drive clamps, or if there are, give them each a tightening turn or two. Those seem to be the most common leak points on these, in my experience.

 

[swathdiver]

My 2c: Check your coolant tees by the firewall. And check around the radiator thoroughly, as well as the water pump shaft. Check also to see that there are no hoses with worm drive clamps, or if there are, give them each a tightening turn or two. Those seem to be the most common leak points on these, in my experience.

This too! ^^^^^

 

[Charlie207]

Just finished replacing the expansion tank. The old one was leaking from the seam along the bottom.

I let it run for a while, and didn't see any leaking, so it'll have to sit overnight and I'll check tomorrow.

I used this video as a guide, and it was stupid-simple.

 

[89Suburban]

Just finished replacing the expansion tank. The old one was leaking from the seam along the bottom.

I let it run for a while, and didn't see any leaking, so it'll have to sit overnight and I'll check tomorrow.

I used this video as a guide, and it was stupid-simple.

Awesome trick there with the washer fluid bottle!!!

 

[Doubeleive]

now for the heater hoses and "T's" because those will be next to fail.

 

[Charlie207]

now for the heater hoses and "T's" because those will be next to fail.

I was just pricing them out. Fun.

 

[iamdub]

I was just pricing them out. Fun.

New OEMs are fine (NO Dorman!). I have no reason to believe mine weren't original (IIRC, I found a date code on them) and they were still holding up at 200K miles.


If you want aluminum, Gruven sells a kit with small hose splices and clamps: https://www.gruvenparts.com/billet-gm-heater-core-coolant-tees/

JTR/Stealth sells just the Ts: https://jagsthatrun.com/collections/best-sellers/products/traditional-hose-tee

I went with the ones from Stealth and bought 12" each of 3/4" and 1/2" of bulk heater hose from O'Reilly.


I also replaced the factory plastic Y connector with the aluminum Dorman 626-553. I cut off the included 5/8" hose and replaced it with Gates.

 

[Doubeleive]

I was just pricing them out. Fun.

ya set of oem T's and hoses will run about $100 or close to it, when I bought mine last time Amazon had the best price
I have had the t break off before luckily I was in town and not stuck on the side of the highway in no-where-ville

 

[iamdub]

ya set of oem T's and hoses will run about $200 or close to it, when I bought mine last time Amazon had the best price
I have had the t break off before luckily I was in town and not stuck on the side of the highway in no-where-ville

I have less than $90 invested in both Ts, hoses and clamps.

 

[Doubeleive]

I have less than $90 invested in both Ts, hoses and clamps.

ya I went back and looked I was way off it's around $100, I must have been thinking of something else

 

[iamdub]

ya I went back and looked I was way off it's around $100, I must have been thinking of something else

Yeah, the Gruven kits (Ts, hoses and clamps) are $95 each- $200ish total with shipping. The Stealth Ts are $30 each- $70ish total shipped. Hose and clamps are cheap, unless you want silicone.

 

[Charlie207]

After a couple days of checking levels and driving, and checking levels, it looks like there's still a slow leak somewhere on top of the old expansion tank leak. Not a great time of the year as I just down want to stand around the engine bay, or lay on the snow under the truck to hunt and peck.

 

[89Suburban]

ya set of oem T's and hoses will run about $100 or close to it, when I bought mine last time Amazon had the best price
I have had the t break off before luckily I was in town and not stuck on the side of the highway in no-where-ville

Mine broke off towing the boat home right after I picked up a pizza at 9 at night in a monsoon in the ghetto, freakin SUCKED. Thank god I had a spare jug of antifreeze in the back.

If this ever happens to anybody you can cut both heater hoses and dig the broken plastic nipple end out of the one heater hose and use it as a splice to bypass the heater core lines. You can use zip ties or tire wire for clamps.

When I replaced everything I put a brass splice into one of the heater hoses with spring clamps as an emergency bypass setup if it ever happens again