ABS Questions

[Lemondrop]

Im messing with my 95's ABS and I believe the Hydraulic Control unit is toast . Im going to do the tests on it tomorrow afternoon (if I get the wifes Explorer to start ) to verify the HCU being dead . I currently have a C1210 ABS Outlet Valve Coil RF Circuit Failure , which my little Ford manual says to runa series of test that show if my wiring is good then the HCU is fried .
Anyway ,
It says for bleeding the unit you need a "T90P-50-ALA" Antilock Brake Adapter so you can turn the pump over and open a valve to remove the air . Anybody know of a alternative to this tool ? How much would it cost to buy a Ford one ?
Id rather fix it myself at home because I have 2 Explorers plus my buddy has a Explorer so sooner or later (his has a dead ABS right now also) Ill be needing the tool or Ill have to pay ford just to bleed the brakes , which means Ill end up having them replace the ABS unit .
Anybody know ? Thanks in Advance .

 

[mrboyle]

As far as I know there is no aftermarket tool that can run he ABS to bleed it.

 

[BradE.]

OTC Enhanced with ABS software can. It's pricey however.

 

[Lemondrop]

Anybody ever think of building a tool to do this ? I may trace out what wires I need to power and build a tool . Seems it needs the motor to run and a valve to open . Motor runs for 60 seconds , after 20 secinds push and hold the valve dump for 20 seconds then release ..... motor runs for 20 seconds more and it's now got the master cylinder and the HCU bled , so you can proceed to bleeding the wheels themselves .
I dunno I may build something ......
Worst I can do is roast a roasted HCU trying

 

[Lemondrop]

I checked everything and the resistance on my HCU is within specs . I also checked the wires going to the HCU from the ABS ECM and it's out of spec . I checked the wires between the HCU and the connector for the ABS computer and they have continuity and no resistance . I got in a hurry because the sun was going down and the mosquitos were coming out in force so I slapped it together without checking to see if either wire had gone to ground .
Ill check those tomorrow and I guess if they are not shorted to ground the HCU must be internally fried .
The resistance at the HCU runs a steady 3.6 ohms on both terminals , if you connect it through the main harness it starts around 8.5 ohms and slowly climbs to between 10.5 and 11 ohms . I don't understand why the resistance would climb ..... never seen it do something like that before without a temp change . I guess I also need to check the wires in the HCU vs. ground .
Anybody got any experience with this ?

 

[Lemondrop]

Wiring diagram was backwards to my connector (showed the harness side in the diagram not the HCU side) so I was probing the incorrect wires . The RF dump valve coil is roasted . Guess Ill be building a wire harness to jerry rig the valves and see if I can bleed them .

 

[dogfriend]

There is a link in this thread to an aftermarket tool by Thexton that is supposed to let you bleed the HCU

Dead Link Removed

 

[Lemondrop]

Thanks , looks like the tool is $168 now . I may go that way but I might go ahead and build one myself . Like I said the valves are supplied with 12 volts and the motor the same so there is no reason I can make a harness .

 

[Lemondrop]

I bought the adapter for bleeding the brakes but it needs a adapter harness .... I swear sometimes I would like to run something up a engineer's *** .
Anybody know the part number of the adapter harness to hook the bleeder "box" to the Explorer ABS module wiring ?

 

[Lemondrop]

Oh , BTW I installed a used HCU , hooked it all up and then figured out I could not hook the bleeder up
I was stuck at that point with air in the system so I bled it best I could and then closed the lines up and took it out on the street .
The pedal was mushy but it would solid up pushing it down . I took it out during a slight rainstorm and mashed the brakes as hard as I could doing 30 MPH . The anti-locks turned on but the pump was making popping , smacking noises . I did this for a few times and then returned home . I bled the brakes again and a little more air came out (was bleeding at the 3 brake lines that come out of the HCU unit , I never bled the calipers themselves) of the lines .
I took it back out and got up to 50 MPH and crammed them . The truck was weaving a little and the ABS pump stopped making noise but the ABS functioned . I repeated the process a few times and it stopped weaving but I could hear each tire locking and unlocking .... "chirping" as the truck stopped . The pedal is solid as a rock now , even better than it has been before the HCU went out .
I still want to "correctly" bleed the unit so Id like to get the harness so if I need to do this again to either my X or my wifes X Ill be prepared .
Anyway , this was a just for your Info post ....

 

[Lemondrop]

I ended up buying the harness I needed from Ebay and finally bled the brake HCU last night . Feels the same as it did so I assume my locking up the brakes and bleeding the brake lines at the HCU cleared the air out of it ... would have been easier with all the proper tools .
Still , I got a used HCU for $40 and I have about another $80 buying the tools . A brand new HCU from Ford costs like $800
Next time I need to do one Ill be ready to go .
If anybody on the east coast / Central Florida ever needs help with thier 95-97 tool wise for the abs , drop me a email Im sure I can help in some way .