Brake fluid leak while replacing motor mount

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

22h0ffers

TYF Newbie
Joined
Dec 12, 2022
Posts
1
Reaction score
0
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.
 

Attachments

  • 373435F7-766F-484E-9E75-656022AF2140.jpeg
    373435F7-766F-484E-9E75-656022AF2140.jpeg
    274.1 KB · Views: 7
Joined
Apr 11, 2018
Posts
6,282
Reaction score
12,257
Location
St. Louis
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.
 

OR VietVet

Multnomah Falls
Supporting Member
Military
Joined
Oct 8, 2014
Posts
19,067
Reaction score
31,163
Location
Willamette Valley
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.
 

Charlie207

Full Access Member
Joined
Apr 13, 2021
Posts
1,166
Reaction score
2,123
Location
LFOD, New Hampshire
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.

Do you happen to have a schematic of the rear heater coolant lines handy?
 
Joined
Apr 11, 2018
Posts
6,282
Reaction score
12,257
Location
St. Louis
Do you happen to have a schematic of the rear heater coolant lines handy?
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

Full Access Member
Joined
Oct 22, 2018
Posts
1,343
Reaction score
2,298
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:
Gruven Tee.jpg
 

Joseph Garcia

Supporting Member
Joined
Aug 2, 2018
Posts
6,386
Reaction score
8,311
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
Joined
Apr 13, 2021
Posts
1,166
Reaction score
2,123
Location
LFOD, New Hampshire
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:
View attachment 387259

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.
 

OR VietVet

Multnomah Falls
Supporting Member
Military
Joined
Oct 8, 2014
Posts
19,067
Reaction score
31,163
Location
Willamette Valley
@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
Joined
May 4, 2016
Posts
2,273
Reaction score
2,217
Location
SoCal
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.
 

Forum statistics

Threads
128,781
Posts
1,805,310
Members
91,760
Latest member
MyCleftNut

Latest posts

Top