How too bleed and ABS unit on a 1993 Explorer 4x4 HELP!!

[Fishermanlife561]

I have been having this issue with my explorer. I have a 93 4x4 that has had a weak break pedal since I bought it about 2years ago. About a month ago I finally got around too replacing the master cylinder hoping too resolve my issue. After doing so the truck has no breaks. With the key off it builds a minimal amount of pressure, but when running goes straight too the floor. The rear breaks barely work and the fronts don't work at all. I have been chasing a break problem ever since. I have replaced the master cylinder 3 times, got 2 new calipers, re-adjusted the rear shoes and bled everything multiple times. I came to the conclusion that there was air trapped in the ABS hydraulic unit (HCU). I read somewhere online that it needed too be taken too ford too be electronically bled if air gets inside. But when I brought it too the dealer they said that an anti-lock break adapter (T90P-50-ALA) and a Jumper (T93T-50-ALA) were necessary too bleed the ABS unit, but both my ABS unit and both tools needed too bleed it are obsolete and that they can't even get ahold of them. This it my last hope of fixing my breaks. If anyone has any information on how too fix this issues of how and where I can acquire those tools would be much appreciated
-Joe

 

[jd4242]

Do you have 4 wheel abs or just rear abs? Didn't think 4 wheel came out till 94.are you bench bleeding the mc first??

 

[Fishermanlife561]

Yes I have 4wheel ABS it is an Eddie Bauer if that makes a difference. And yes every master that I have put in has been bled. I have gotten all the air I can get out of the system. I have had about 5 mechanics and 3 master technicians look at it

 

[IAmTodd]

Have you tried replacing the ABS pump? Sounds like it may be faulty.

I've bled mine by activating it on a gravel road close to home and bleeding immediately after doing that. That's assuming you have enough brake power to activate ABS.

 

[jd4242]

Yes I have 4wheel ABS it is an Eddie Bauer if that makes a difference. And yes every master that I have put in has been bled. I have gotten all the air I can get out of the system. I have had about 5 mechanics and 3 master technicians look at it

Eww yea I'm with you then, probably is the abs unit.I have heard they can be a pia but I don't have any suggestions or experience with it sorry.ill do some searching also to see if I can come up with anything. Would like to know how to just for future reference.

 

[Fishermanlife561]

I had come too that same conclusion, so I went too the junkyard and pulled the best looking replacement ABS unit. But the problem persists. The shop Forman at ford told me the same thing. Take it on a dirt road and lock up the breaks, but I only have rear breaks, my fronts have no stopping power so only the rear lock up. leading me too believe that I'm only activating the rear portion of the ABS unit so air could still be trapped in the front break portion. Which I cannot get too activate without any pressure too the front.

 

[jd4242]

Looks like your need to go to the dealer.the tool cost over $200+


QUOTE. ..

Here are a few quotes from the Ford Tech CD for a '95 -#"The brake master cylinder and Hydraulic Control Unit must be bled using Anti-lock Brake Adapter T90P-50-ALA and Jumper T93T-50-ALA. If this procedure is not followed, air will be trapped in the HCU which eventually leads to a spongy brake pedal.1. To bleed the brake master cylinder and HCU, disconnect the 40-pin plug from the Electronic Control Unit and install the anti-lock brake adapter to the wire harness 40-pin plug.a. Place the bleed/harness selector in bleed position.b. Turn the ignition switch (11572) ON. At this point the red OFF indicator on the adapter should turn on.c. Push the motor button on the adapter down. This starts the pump motor. The red OFF indicator turns off and the green ON indicator turns on. The pump motor will run for 60 seconds once the motor button is pushed (you do not need to hold the button down). If the pump motor is to be turned off for any reason before this 60 seconds has elapsed, push the abort button and the pump motor will turn off.d. After the first 20 seconds have passed, push and hold the valve button for 20 seconds. This bleeds any trapped air from the brake master cylinder and HCU.e. The pump continues to run for an additional 20 seconds after the valve button is released.2. Bleed the brake lines in the following order. Right rear, Left rear, Right front, Left front "Additionally, the Ford Tech info is clear that you can bleed the brakes in a normal way but only if you make damn sure you keep the reservoir full enough to keep air out of the system. Once air gets in the system, you're screwed if you don't have the electonic adapter/jumper to control the HCU for bleeding.Looks like you may have gotten air in the Hydraulic Control Unit (HCU) somehow and you now do need the adapter tool to bleed it. The adapter is an electronic control unit that plugs in to the controls of the HCU and helps sequence you thru the process of bleeding it.From my quick review of Ford Tech CD, it appears possible to have a firm pedal with the vehicle not running and then have problems show when you energize the ABS system with vehicle running. In other words, when you start the vehicle the HCU comes alive and it shows the air trapped in the HCU. With the ABS system unenergized (vehicle off) you really do not have the HCU/ABS in the hydraulic loop.

 

[jd4242]

I know this may sound far fetched but what if you jack the rear end up off the ground safety. .....leaving the front on the ground.. then put it in drive and slam on the breaks?? It will think the front wheels are locked up because they are not spinning and activate abs...crazy idk but may work.

 

[Fishermanlife561]

Here's the only issue wth that according too the dealership I'm brought my truck too both the tools and the ABS unit are considered obsolete so ford no longer makes the tool or the part therefor they cannot even get ahold of the tool too actually bleed my ABS. After telling me this they gave me the option of the "redneck way" which was locking up the breaks on a dirt road. Which I tried for hours and it has yet too work. So basically I need too acquire the proper tools and even then the ABS unit could be faulty itself.

 

[IAmTodd]

I know this may sound far fetched but what if you jack the rear end up off the ground safety. .....leaving the front on the ground.. then put it in drive and slam on the breaks?? It will think the front wheels are locked up because they are not spinning and activate abs...crazy idk but may work.

That may work or it may just completely disable the system as a fault.

Here's the only issue wth that according too the dealership I'm brought my truck too both the tools and the ABS unit are considered obsolete so ford no longer makes the tool or the part therefor they cannot even get ahold of the tool too actually bleed my ABS. After telling me this they gave me the option of the "redneck way" which was locking up the breaks on a dirt road. Which I tried for hours and it has yet too work. So basically I need too acquire the proper tools and even then the ABS unit could be faulty itself.

It's not redneck if it works...

Sadly the 93-94 system seems to be rather rare with sparse documentation. I know that air has gotten into mine and has worked it way out with bleeding. If yours isn't firming up at all I think you may have an issue bigger than just air in the system. If one of the seals has blown in the ABS pump it could be allowing pressure to bleed back.

 

[Fishermanlife561]

What kind of options do I have for deleting the ABS system completely? I know that there are models that don't have ABS, but what kind of wrk does it entail or is it even possible too eliminate the ABS?

 

[jd4242]

Get the lines from a pre 93 and mc