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Where would you use Teflon tape in a brake system? It's inert, anyway.
 

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Discussion Starter · #22 ·
Where the hard line goes into the transfer block for the rubber lines. There was teflon on the coupler threads and the flare for the hard line.
 

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Discussion Starter · #24 ·
I know. The dealer did it. That was how they 'fixed' my leak a few years ago. They put a warranty on it and it was working and i wanted my truck back (it sat for a week while they ordered the wrong parts).

The dealership was the only one near me at the time.
 

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Discussion Starter · #26 ·
I even brought up how compression fittings work lol

First and only experiance. They made a lot of mistakes that visit and lost me as a future customer. The manager lady and service writer lady were nice though.
 

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There is the possibility you have an issue with the ABS module leaking internally.
 

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Discussion Starter · #29 ·
There is the possibility you have an issue with the ABS module leaking internally.
This is the longest my brakes have stayed 'not soft' so im hoping i missed that bullet and it was the "repair".
 
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Discussion Starter · #31 ·
Couple panic stops today (florida is lawless) and it still feels good.

Anyone gravity drain before? Ive got half a bottle left and id rather bleed the brakes again (just incase) then to let it collect water on the shelf. My wife is tired of helping haha.
 
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Couple panic stops today (florida is lawless) and it still feels good.

Anyone gravity drain before? Ive got half a bottle left and id rather bleed the brakes again (just incase) then to let it collect water on the shelf. My wife is tired of helping haha.
I only do a gravity bleed on a known good system. In my experience, it simply doesn't provide the velocity to get junk or air out.
They ain't cheap, but the Motive pressure bleeder is the bees knees. I may only use it once a year or less but it was a solid investment for sure. Took me 30 -40 minutes to completely flush the truck. The really nice part is you can be hands off and cycle the key while it's pushing fluid. That let's the ABS do its self test to purge a little fluid through it as well.
 
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No, not really. It's a little better than gravity bleed, but the pressure is so low you can't do the velocity needed to accomplish the things you highlight. But certainly better than vacuum bleeding.

We had to do the vehicle testing to sort out the products and meet FMVSS criteria; pedal travel was an important aspect. Not only for "feel," but an assessment of friction material compression, caliper flexing, and keeping the knee or runout of the boosters where you would not lose the boosted line pressure to pedal effort ratio when evaluating stopping distance and fade resistance. Bleeding out all the air was of utmost importance.

I could spend any amount of money for bleeding tools from any supplier. And suppliers would ask my company if we would use their product and endorse it. I usually took the products and then sent back a report of how well they did - we never supported anyone's product.

A Motive pressure bleeder, like others, is run at 15psi, with a max of 20 psi. A better one is the Branick steel containers that the DIY user will never buy; it is run at 60psi with a diaphragm separating the fluid from the air. The more important aspect, the 60psi, is over the entire diaphragm surface area (air over oil), so you have much higher pressure in the hydraulic system. It's a dangerous tool when it leaks under pressure.

So I could have spent $10,000 on brake bleeding equipment. We were a friction material supplier, OE, and Aftermarket. If you own a Superduty, I tested, and the company sold those brake pads to Ford and the aftermarket. Unless we had to bleed out the ABS unit, we did the two-person bleed. It was the only way to get all the air out of the system fully, so we had an accurate and consistent reading of pedal travel vs. pedal effort.

The Motive style bleeders are in the range of 15 to 30psi, depending on what you get. Every vehicle test starts with new rotors, brake pads, and calipers, all four corners. And vehicle testing takes either 4 or 10 days. That's a lot of brake flipping over 25 years with a group of 8 to 20 test drivers.

At the start of every test, I had the setup "fingerprinted" to know we had the correct travel to pedal effort ratio. The knee or runout of either a vacuum booster or hydroboost is travel-dependent. At some point, you run out of assistance, and you get into a "manual" pedal mode, just like if the booster failed - which is another part of the testing we had to do - failed booster, failed primary camber of the master, failed secondary chamber of the master.

This compares vacuum vs. hydroboost on a 2005 to 2008 brake system and representative of doing a manual bleed with the engine off. The first of the left graphs is what is important. The hydraulic pressures you can achieve using the brake pedal above the Motive et al. bleeders. At the lower pressures, we would also tap the calipers with a small hammer to vibrate loosen the air, which was about 95% effective.

Slope Rectangle Font Triangle Line


This would be our first stage. Next, we would bleed with the engine running, and the boosted pressures were much higher, where when bleeding, you would get the fluid turbulence in the caliper around the pistons to loosen any air bubbles that would adhere to the walls.

This is the second "fingerprint" data (again, 2005 to 2008 Superduty) that would allow the vehicle to continue the test or run another bleed to get the travel back. One interesting aspect of the data is you can see how much more effective a hydroboosted Superduty is, getting a higher brake fluid pressure for a given pedal effort. Before or after the booster knee where the assist falls off. Brake pedal travel is relatively the same for a given hydraulic pressure.

Rectangle Slope Font Line Parallel


We had years and the means to assess the best methods for eliminating the air out a brake system. The old two-person bleeding was the best in getting all the air out - which would also be contaminates for old fluid bleeding. No one wants to be responsible for ruining a $10,000 vehicle brake test because there was too much air in the hydraulics.
 

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Discussion Starter · #34 ·
Ive used the motive one before. Its never worked right.

Ill just make my wife help me.

Thanks for the input.
 

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Interesting. I've had really good results with the Motive. Even with a completely empty Jeep system.
 

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Discussion Starter · #38 ·
I could never get them to seal correctly. Tried it with several makes and models and it worked on my rlfriends mustang but that was it.
 

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TET, depends on the situation. Using the Motive is a good way to what I would call prefill the system. I have one! We did try the method at work with our fully instrumented vehicles. It just never got all the air out to the extent we need to. Using it and tapping on the calipers helps to get there, too. That should be tried.

For our work, we had to have "assembly line" conditions for each test. And as I mentioned, part of my test analysis was to look at pedal travel during different phases. The friction material is compressive, especially when hot. Doing the two-person bleed was the most reliable way of getting there. Sometimes using IDS to electronically bleed still need a two-person bleed with off-the-shelf calipers.

My wife is not the happiest doing the seat work.
 
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