How to bleed the brakes with rear ABS?

Tiny
GOGOJUICE6
  • MEMBER
  • 1994 FORD RANGER
  • 2.3L
  • 4 CYL
  • 2WD
  • MANUAL
  • 113,000 MILES
I replaced the master cylinder in my truck. According to Haynes, after bleeding master cylinder, I have to bleed the ABS unit. There's no bleeder screw in it, just an 7/8 nut, (which I don't want to mess with it, not knowing what is it for) and then, continue with the standard bleeding pattern. How do you bleed a screwless ABS unit, if so?
Thanks for your help, and
Happy Holidays to y'all.
Sunday, December 1st, 2024 AT 6:34 AM

12 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Happy Holidays to you as well. Can I ask if you have a good brake pedal, and the system seems to work okay? If so then you don't need to bleed the ABS system. The only way to bleed the ABS is with a scanner to open the valve inside the control valve. Please go over this video to show you what I am talking about:

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

Please let us know what happens.
Was this
answer
helpful?
Yes
No
+1
Sunday, December 1st, 2024 AT 12:43 PM
Tiny
GOGOJUICE6
  • MEMBER
  • 76 POSTS
Brakes were fine until the right rear wheel started locking up. Thinking it was air in the line, bled it. Nasty dark fluid and air was coming out until it stopped. Maybe clogged line. Took it off and it is clogged. Ordered both sides, should be here by Thursday (hopefully). I'm not sure if my obd 1(it's a '94) can pick up brake issues. I was told I could bypass ABS, is this true? If so, how do I go about it?
Thanks for your help and knowledge, Ken.
Was this
answer
helpful?
Yes
No
Monday, December 2nd, 2024 AT 9:06 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
The ABS system will not make the tire lock up; I would not worry about the ABS system if you have good brake pedal. Here is a guide on what makes the brakes lock up, please go over it to help fix the problem:

https://www.2carpros.com/articles/a-comprehensive-guide-to-fixing-automotive-brakes-locking-up

Please go over this guide and get back to us.
Was this
answer
helpful?
Yes
No
+1
Monday, December 2nd, 2024 AT 10:12 AM
Tiny
GOGOJUICE6
  • MEMBER
  • 76 POSTS
Great, I'll replace lines, check the wheel cylinder and check for grease leaks. Bleed and see how it goes. Will let you know in a few days.
Outstanding article.
Thank you so much for your help.
Was this
answer
helpful?
Yes
No
Monday, December 2nd, 2024 AT 11:37 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
You are welcome, thanks for taking the time to read it, most people just want the, "put a piece of tape on it that will fix it@!" Style answers lol.
Was this
answer
helpful?
Yes
No
Tuesday, December 3rd, 2024 AT 9:23 AM
Tiny
GOGOJUICE6
  • MEMBER
  • 76 POSTS
  • 1994 FORD RANGER
  • 2.3L
  • 4 CYL
  • 2WD
  • MANUAL
  • 113,000 MILES
I just replaced mc (bled it)wheel cylinders, rear brake lines, including center flex hose, shoes, flushed and bled system and brake pedal still goes down, almost to the floor. What am I doing wrong?
Thanks for your help.
Was this
answer
helpful?
Yes
No
Thursday, December 19th, 2024 AT 10:32 AM (Merged)
Tiny
MECHTRIX
  • MECHANIC
  • 382 POSTS
Might be time to replace the master cylinder.
Was this
answer
helpful?
Yes
No
Thursday, December 19th, 2024 AT 10:32 AM (Merged)
Tiny
MECHTRIX
  • MECHANIC
  • 382 POSTS
Or the brake booster. Check those first. Hope this helps, good luck.
Was this
answer
helpful?
Yes
No
Thursday, December 19th, 2024 AT 10:32 AM (Merged)
Tiny
GOGOJUICE6
  • MEMBER
  • 76 POSTS
Master cylinder is brand new.
Was this
answer
helpful?
Yes
No
Thursday, December 19th, 2024 AT 10:32 AM (Merged)
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Did you bench bleed the master, also how is the rear brake shoe adjustment? Please go over this guide and video,

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

and

https://www.youtube.com/watch?v=WDxvEQrMkBg&t

To help isolate the problem you can use vise grips with fuel line over the jaws to gently close down the brake flex lines on the front and rear of the system. Let me know what happens.
Was this
answer
helpful?
Yes
No
+1
Thursday, December 19th, 2024 AT 10:35 AM
Tiny
GOGOJUICE6
  • MEMBER
  • 76 POSTS
Hi, Mr. KenL,

Didn't bench bleed master cylinder, because I read somewhere, you could bleed it while mounted on booster.
Thanks for the help and links.
Greatly appreciated.
Was this
answer
helpful?
Yes
No
Thursday, December 19th, 2024 AT 1:42 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
No problem that what we are here for, let me know how it goes, have a good weekend :)
Was this
answer
helpful?
Yes
No
Friday, December 20th, 2024 AT 9:23 AM

Please login or register to post a reply.

Related Bleed - Flush Content

Bleed and Flush Your Brake System Correctly
VIDEO
Bleed and Flush Your Brake System Correctly
Instructional repair video
Brake System Flush
GUIDE
Brake System Flush
An automotive brake system flush is similar to a standard brake system bleed except for all of the brake fluid is flushed out of the brake system components such as the...
VIEW MORE