Cracked - Split brake line...?

Took a short trip to the store and felt like I was having to push the brake pedal all the way down to stop. I had to check my seat adjustment thinking it didn't auto adjust when I started the truck and that wasn't it.

Noticed the BRAKE light come on while in the drive thru for a coffee and figured maybe that was the truck telling me I needed new pads but at a minimum I planned to inspect the system. Figured I was close on pads anyway so not too concerned. Nursed it 2mi home and parked only to see the fluid in the driveway.

Looked under the truck and sure enough one of the rear lines (pass side) appears to have cracked or split? Fluid everywhere and the reservoir is empty. Just got underneath long enough to see the mess and snap a pic, haven't thoroughly inspected the source of the leak yet. Truck is kept outside in driveway and pretty sure this wasn't intentional, so not going down that road.

Just got back from a camping trip over Easter weekend pulling a 5K# trailer through some 7% grades (in the rain coming home). May have driven 10mi since then, glad this didn't manifest on the trip home with the camper.

2014 1794 CM: 73,000mi. Purchased 10/23 with 65,000mi. At least 3K of those miles are towing the trailer. Truck didn't come with OE brake controller, I installed a Redarc Tow Pro Elite.

Was considering the Alcon kit eventually, wanted to do the BM trans pan first. Might have to rethink things...

 

That is terrifying. Looks like the rubber brake hoses have been contacting the exhaust pipe under suspension compression.

 

Excellent observation 600lb of tongue weight from the trailer likely although I do use a WDH and the truck sits pretty level when hooked up.

I'll look closer but I think the mark on the exhaust was from the spare tire. Still appears to be close enough to be damages from radiant exhaust heat. I removed the spare a few weeks ago and have been eyeballing a new exhaust system. This might be my sign to jump on this @reywcms

• New Exhaust System | Toyota Tundra Forum (tundras.com)

 

Already eyeballing this: '07-21 Toyota Tundra SDHQ Built 6 Piece Brake Line Kit (sdhqoffroad.com)

Will likely apply some header wrap on the exhaust section that cross' over the brackets until I get a new exhaust installed.

 

Post pics of the area where it leaked once you find it.

 

That's some scary shit... you don't have a crazy lift or anything do you? Do those brake lines get tension at full droop?

 

Not the first time I've seen this with duals setup that way..

 

6112's and 285/75/17

 

You sure about that? Looks like 2 perfectly spaced brake line witness marks.

 

Agreed, the more I look at the bigger picture that's what I'm thinking. I'll be heading over to SDHQ tomorrow for their braided stainless line kit and address the exhaust issue shorty after.

 

Right, but you're not running a block or aftermarket leaf packs that would require extended brake lines? I'm at around 1.5" of lift and a shitload of droop with my RXT leafs and was able to squeak by without extending the lines. It's now higher on the list after seeing this.

 

If that's the TRD exhaust that shouldn't be the cause. The exhaust is further to the rear of the axel and shouldn't be contacting on that side of the pipe...

 

It's not TRD; unknown aftermarket cat back that was on it when purchased. Been wanting to change it anyway, don't like the dual side exit.

Factory leafs/shackles in the rear, no blocks.

I'll get more pics up shortly...

 

Well that makes a lot more sense then. The SPD exhaust should do nicely, but ask @reywcms about all that low end torque you’re leaving on the table…

 

Here’s how the driver side pipe routes on the TRD exhaust, for reference

 

It’s real, I also suffer imaginary torque loss that doesn’t show up on a dyno.

Much better, the metal brake line are more robust.

 

Shhh you weren’t supposed to see that. I make sure to grease that every 5k miles so it slides easier

 

lol sooo much hp and tq loss especially from this exhaust and Whipple. Should have a fire sale for it all.

 

Here is the culprit:

So here is what I'm looking at for a fix: '07-21 Toyota Tundra SDHQ Built 6 Piece Brake Line Kit (sdhqoffroad.com) I'm sure I could find them cheaper, but SDHQ is close, has them in stock and I have a trip towing the trailer to San Diego planned next weekend so I feel a little pressed for time.

Per SDHQ:

• Front Brake Line: +0.75" over stock
• Rear Brake Line: +2" over stock
• Includes the axle to caliper brake line.

I measured the OE lines, and all seem to be 12". I'll use the front +.75" lines up and the axle/caliper lines from the kit. I don't think I'll use the +2" rear caliper lines and will just sit on those for future use.

While I'm at it I think I'll do brakes/rotors because A) why not B) truck is new to me and with all the towing I expect to do this summer I want peace of mind.

Just for shits and giggles I will apply some header wrap on the exhaust section that cross' over the brake lines until I can purchase the SPD exhaust.

Here are pics of the current exhaust:







So fortunate this didn't happen Sunday on the way back from Roosevelt Lake towing up/down 188 and thru Devils Canyon in the rain...

 

Absolutely agree doing all that while you’re there

 

Any downside to chopping the exhaust in front of the axle and running that for a few weeks? Never did like the side exit duals...

Maybe clamping a couple 90* downturns on there?

 

Do it!!!

 

You may lose some tq. I think that brake line mount can be modded and moved down a bit

 

X2

 

Depends on state laws, but no I don't see a performance issue with it. Noise issue maybe...

 

As long as it doesn't throw a code it's not an issue in AZ. Im not due for emissions until Oct 25 anyway. This will just be for a month or so.

 

Thats what I did, no regrets…just make sure your exhaust is well supported….otherwise driveshaft gets some unintended weight reduction.

 

Ye olde lathed shaft

 

OP are you at all concerned about your brake performance after the repairs are done, because the reservoir went dry, and air likely reached the ABS pump?

I ask because a friend of mine put his '08 Tundra up on blocks to do a bunch of maintenance, new rotors and pads all around and rebuilt his calipers. While the brake lines were disconnected he didn't cap/plug the lines properly, and he says his brakes have never been the same since (as in don't seem to build up pressure as effectively).

We've bled and rebled his brakes probably a dozen times, bench bled a new master cylinder then installed, and tried going down dirt roads and slamming the brakes to get the abs pump to actuate, all to no avail.