ABS Brake Bleed issue

Tiny
TERRY MOORE54
  • MEMBER
  • 2013 FORD F-150
  • 5.0L
  • V8
  • 2WD
  • AUTOMATIC
  • 98,000 MILES
Replaced the vacuum booster and master cylinder in my truck. Went to bleed the brakes and no fluid would come out of the rear bleeders. It did, however, bleed from the front bleeders. Well, the next thing I did was research a scanner that would auto bleed ABS. In doing so I found a XTOOL Diagnostic Tool which was approximately $360.00 I thought it to be a good choice but upon receiving it I quickly found out that the directions were not meant for me. I tried it out on the f150 to no avail so I searched and searched again for a video and that's when I came across yours thank God. So I'm wondering am I on the right track by thinking that the tool that your using will fix my problem? All the while after I did what I did to bleed the brakes the front ones felt okay but the back brakes felt like they were dragging although no fluid was coming out after bleeding. And I did bench bleed the master cylinder so I'm at a loss. Please help. My name is Terry I am an old school mechanic without knowledge of the new age.
Monday, March 7th, 2022 AT 5:16 PM

12 Replies

Tiny
BORIS K
  • MECHANIC
  • 836 POSTS
Hello,

The ABS hydraulic block should bleed through without any activation via scan tool.

See good video below
https://www.youtube.com/watch?v=nQRnKyVyMuQ&t=4s

Try bleeding the brakes and while pressurized crack open the outgoing brake lines from the ABS to the rear wheels. Brake fluid should leak out.

How to bleed ABS system.
https://youtu.be/nQRnKyVyMuQ

Please let us know how you get along.

Cheers, Boris
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Tuesday, March 8th, 2022 AT 4:05 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
I think you are correct that if you are getting no fluid out of the rear that this could be an ABS bleed issue. However, was this issue happening prior to replacing these parts? Meaning is this why you replaced the master or is this an issue only after replacing them?

The tool that Ryan is using should work on your vehicle as well.

https://www.youtube.com/watch?v=nQRnKyVyMuQ&t=4s

However, if you bench bled the master then I would not expect this to have no fluid to the rear because there should have already been fluid purged through the lines.

So that means if you replaced the master, bench bled it and then went to the rear and have no fluid at all from the very start of bleeding then I doubt you had fluid there from the beginning. Which means you most likely had a soft pedal which is why you replaced the master.

Please let me know if this is what is happening, and we can go from there.

Thanks
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Wednesday, March 9th, 2022 AT 4:30 AM
Tiny
TERRY MOORE54
  • MEMBER
  • 7 POSTS
This all happened after replacing the master cylinder and vacuum booster. The reason why the master cylinder and vacuum were replaced was due to having a soft pedal after returning from an errand around town. Practically had no brakes. So, like I said we replaced both unit bench bled the master cylinder. I checked the throw on the vacuum booster to the master cylinder put everything together went to bleed the brakes and no fluid out of the rear bleeders but fluid out of the front bleeders. That's why I'm going nuts, lol. I am a mechanic from the days before ABS so I am being schooled as we speak. Please advise. I am getting the tool that Ryan was showing in the video I hope it works.
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Wednesday, March 9th, 2022 AT 6:14 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Okay. This could be an ABS issue but in this case the ABS is simple so don't let it confuse you. Basically, all it does is pressurize the fluid in a hard breaking situation so if you removed the master then the ABS should not need to be bleed using a scan tool so let's not worry about that for now.

When you bench bled the unit did you use clear lines to route back to the reservoir so that you can confirm you actually had fluid movement out of each port?

There is a chance that the master is the issue.

At this point, I would suggest we remove the lines and route them back and bleed it again just to confirm the master is sending fluid. Then we may have to disconnect the rear lines and check for obstructions. You have multiple connection points so we may need to look for a leak as well, but I suspect you would have found that.
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Wednesday, March 9th, 2022 AT 7:48 AM
Tiny
TERRY MOORE54
  • MEMBER
  • 7 POSTS
Yes, when the unit was bench bled, I used clear lines and fluid was coming out both ports. I am waiting right now for the scan tool to show up from ups. I am hoping that will take care of it. This should not of happened that's why I'm a bit confused. I do not want to have to replace the hydraulic unit. I feel bad enough cause this is my friend's truck and when I started, I told him no problem. I tried to save him some money rather than getting ripped off at the dealer. Now I'm looking bad but I am feeling that I have done nothing wrong, but I still need some help. I can't thank you enough.
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Wednesday, March 9th, 2022 AT 8:00 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Okay. Let us know what happens with the scan tool but the original issue was a soft pedal?

Do you still have a soft pedal? If you have no fluid, then I imagine you have no pedal at all?

If you have a hard or firm pedal and no fluid to the rear, then you most likely have a restriction in the rear system. More than likely a collapsed rubber line.
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Wednesday, March 9th, 2022 AT 8:51 AM
Tiny
TERRY MOORE54
  • MEMBER
  • 7 POSTS
No, no soft pedal. Just no fluid coming out of the rear bleeders and no leaks anywhere.
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Wednesday, March 9th, 2022 AT 8:54 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
If there is a firm pedal and no fluid, then there has to be a restriction in rear branch.

I would suggest starting to open the lines starting at the rear and open the connection points to see where you get fluid. Once you have then your restriction is behind that point.

If you think about it, the only way you can have a firm pedal is if there is something for the fluid to press against. When there is air or a leak you don't have that pressure build up and the pedal drops.

So, if you don't have that then that fluid is pressing against something, and it clearly is not the rear brakes.
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Wednesday, March 9th, 2022 AT 2:11 PM
Tiny
TERRY MOORE54
  • MEMBER
  • 7 POSTS
Going to get started just received the MK808 and registered it and its charging. Let me get this going and I will let you know how it's going. Thanks again guys.
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Wednesday, March 9th, 2022 AT 3:19 PM
Tiny
TERRY MOORE54
  • MEMBER
  • 7 POSTS
Sorry guys since I got the scanner late and read the instructions and charged it up. I didn't get done what I was going to do so please hang with me, I am going to attempt it again tomorrow since no one is in a big hurry thank God. Laters guys.
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Wednesday, March 9th, 2022 AT 5:45 PM
Tiny
KASEKENNY
  • MECHANIC
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Haha. Totally get it. Not enough time in the day sometimes.

Thanks for updating us but we will be here whenever you get to it.
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Wednesday, March 9th, 2022 AT 6:03 PM
Tiny
TERRY MOORE54
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Thanks guys, appreciate ya'll.
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Wednesday, March 9th, 2022 AT 6:05 PM

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