I was replacing the passenger side motor mount today in my new to us 07 yukon XL (which will replace our 07 Yukon) when brake fluid decided to rain on my face. (And an trip to the clinic cause I somehow got metal embedded in the inside of my eyelid, but I digress.) it only leaked when jacking up on the motor and the leak came from two hoses up by where you would grab the dipsticks and I went to bleed the brakes when done and im getting so much air. I need more fluid now to try again, it’s definitely an excessive amount of air. My question is why did those lines start leaking and do I replace them or can I repair them? Also I can’t find them on the internet. And also, there has to be air leaking back into the system from there right? Again they don’t leak any other time. Usually I’m pretty ok with vehicles but today has been something else. I’m sorry for the long ramble, I’m tired a bit delusional. Thank you for any responses. It’s that snap together plastic to hard line. If you look close enough you can see a drop.
Brake fluid leak while replacing motor mount
- Thread starter 22h0ffers
- Start date
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gooffeyguy
Tom
Those aren't brake lines, those are coolant lines for the rear heater. They each attach to "T" right there on the firewall that also attaches to the heater core and those 2 rubber coolant hoses that run towards the front of the motor.
Welcome to the forum.
What @gooffeyguy said. The mount was bad enough that the lines/hoses got rubbed thru and are partially blocked when engine is settled. You likely induced air in to the brake system but unsure on some of your description. How did you determine that it was brake fluid. That leak(s) cannot be brake fluid or you would not be able to drive the rig and stop it.
What @gooffeyguy said. The mount was bad enough that the lines/hoses got rubbed thru and are partially blocked when engine is settled. You likely induced air in to the brake system but unsure on some of your description. How did you determine that it was brake fluid. That leak(s) cannot be brake fluid or you would not be able to drive the rig and stop it.
Charlie207
Full Access Member
Do you happen to have a schematic of the rear heater coolant lines handy?
gooffeyguy
Tom
No I don't, but the lines run along the passenger side under the vehicle and enter just behind the rear wheel well. the same spot where condensate drips when the rear AC is on. A couple members on here have replaced or repaired these so I know I've seen posts with pics, but can't remember who
donjetman
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what is pictured are coolant lines. There are 2 plastic heater hose T-fitting there that almost always leak/break with age. I installed 2 gruvenparts.com aluminum replacements:
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If you replace the Tees with similar parts, do NOT use a Dorman replacement Tee. Get OEM Tees (if not the Gruven Tee above).
Charlie207
Full Access Member
Dang... just the aluminum piece is $95 each.
I can see mine aren't leaking or broken when I stick my head in there with a flashlight.
@22h0ffers, I am a little worried about how you mixed up the brake fluid with coolant and then complaining about air in the brake system. Are you going to respond back to the comments?
petethepug
Michael
Purchase the heater coolant tees or factory replacement hoses for the truck now. When they go they’re nowhere to be found except the dealer who’s happy to sell them to you for hundreds. A broken T will drain the motor of coolant in 15-30 seconds forcing you to shut down the motor. That means no power brake, no power steering and a windshield full of steam. If you run the motor until you’re off the freeway, good bye engine.
Keep the T’s, clamps and hoses in the spare tire cavity or in the storage compartment at the left rear of the truck. When it does happen you’ll be back on the road quickly or have everything to do the job on your time & terms. My Indi shop charged $4h to replace both because I had to get outta there. Dealer parts were his only option when I was towed in.
Keep the T’s, clamps and hoses in the spare tire cavity or in the storage compartment at the left rear of the truck. When it does happen you’ll be back on the road quickly or have everything to do the job on your time & terms. My Indi shop charged $4h to replace both because I had to get outta there. Dealer parts were his only option when I was towed in.
Charlie207
Full Access Member
Do you know the part# by chance? Rock Auto doesn't seem to have the GM Ts in stock.
@Tonyrodz provides the part numbers with pics in this post:
What is this line that leaks?
After some prolonged absence and a quite few repairs, I need some help again. After some extreme cold in Colorado, I had to replace the throttle body sensor as truck went into limp mode. All went well, but when deep under the hood I realized I have a small coolant leak from a line pictured. What...
www.tahoeyukonforum.com
Amazon has them most of the time.
Charlie207
Full Access Member
@Tonyrodz provides the part numbers with pics in this post:
What is this line that leaks?
After some prolonged absence and a quite few repairs, I need some help again. After some extreme cold in Colorado, I had to replace the throttle body sensor as truck went into limp mode. All went well, but when deep under the hood I realized I have a small coolant leak from a line pictured. What...
Found them on Fleabay from a dealer an hour away for cheapest w/free shipping.
Is this a messy job, e.g. coolant everywhere? Or, will it be painless because of the height of the connections?
If you only had to replace the tees, it wouldn't be messy at all. But you also have to replace the heater hoses (and I would replace the one with the Y in it with the Dorman replacement that uses a metal Y fitting), and that means removing the other ends that connect to the water pump. Those sit about halfway up the height of the radiator, so you're going to lose a gallon of coolant at least unless you work really fast.
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