Cleaning ABS sensor magnets

Discussion in '80-Series Tech' started by Trunk Monkey, May 19, 2005.

  1. Trunk Monkey

    Trunk Monkey Moderator

    Messages:
    7,559
    Location:
    Salt Lake City
    My 80 has been having ABS issues. Started with the ABS activating when I was braking to a slow stop. I pulled the sensors and cleaned them, didn't see anything on them other than grease. That took care of it for a couple days, but now the ABS light is on permanently.

    I'm going to pull the code and see if the front sensors are bad. My pocketbook hopes not. :frown: For anyone that's thought about cleaning the magnets, it's a .5 banana job, here's a couple pics.
    Last edited: Jul 12, 2007
  2. rgsiii

    rgsiii SILVER Star

    Messages:
    771
    Location:
    Valley, AL
    You may be in for an expensive times. I had a similar problem when a "Cruiser shop" botched a knuckle job. There are some shims that helped for a brief while. Then the symptoms came back. I ended up having to send CDan about $300 to fix the ABS.

    Unfortunately, that wasn't all they messed up with the knuckles. :frown:
  3. semlin

    semlin rocker SILVER Star

    Messages:
    5,147
    Location:
    north of 49
    is that an "after" shot of the abs sensor harness after cleaning? It looks brand new. Mine is caked in crap and I think it is black.
  4. Trunk Monkey

    Trunk Monkey Moderator

    Messages:
    7,559
    Location:
    Salt Lake City
    Nope, just as it was on the knuckle. The shot of the magnet is after I cleaned it. I'm guessing the ABS system is tempermental, the light is back off this morning. :rolleyes:
  5. MartinMac

    MartinMac

    Messages:
    7
    I can feel the abs activating just before stopping. At first I thought it was the break sticking. The garage I bought it from told me it's because it's lifted about 6 inches at the rear. Also the abs light comes on occasionally and then this problem is gone.

    I'm new to this vechicle and would appreciate any advice.
  6. beno

    beno 33030-60450 Moderator Supporting Vendor

    Messages:
    13,346
    Location:
    Covington, GA
    Just hack all of that ABS stuff off!!

    Sell it and you've made some money and have a vehicle that brakes better (at least in my opinion).

    :grinpimp:

    I'm in the process of taking out all of the wiring for ABS and getting rid of the ABS box in the engine compartment as well. once that's out, i'll have a nice open area for some engine compartment accessories.

    -o-
  7. I have he same issue, did you manage to fix the ABS issue?
  8. Ebag333

    Ebag333

    Messages:
    8,163
    Location:
    Medford, OR
    Is the ABS light staying on? Are the brakes pulsing when stopping? What year truck do you have? More information is needed.
  9. Tyler93

    Tyler93

    Messages:
    485
    Location:
    Lander, WY
    I had the same problem about 3 months ago, ABS would only activate when stopping slowly. The shop I had do my front wheel bearings tried to say it was my off brand tire! (same size and tread depth different ply). I didn't buy it. I asked them to go back through it and it was either shims or dirty sensor. Either way didn't cost a thing. Good luck.
  10. I too have been having the exact problems. When i slow down to a slow stop 60% of the time I get the pulsating brake. Then every other time I drive the abs sensor light comes on. Im getting my rear o2 sensor done this week and going to check the magnets as well. Word on the street is 515 for new abs sensors. OUCH that would hurt alot. But I will let you know the status at the end of the week. Thanks for eve1s help. God Bess America dont forget to vote.
  11. HI I have a 1994 LC 80 VX. the ABS light is off, but the brakes is pulsing when stopping.
    Last edited: Jun 26, 2010

  12. ndega01

    ndega01

    Messages:
    14
    I'm having a similar problem with mine. Do you know what they did with the shims. Maybe I could let the shop that did mine know what they need to change.
  13. ndega01

    ndega01

    Messages:
    14
    rgsiii,

    What did you have to buy from CDan. I am having the same problem. I sent the knuckles to be serviced by a drive line specialist here in Atlanta and the next thing I know I am having trouble with my ABS. One of the sensors activates when I am braking and the car is close to coming to a stop. What did your have? and what did you do to fix it?
    Last edited: Dec 22, 2009
  14. ndega01

    ndega01

    Messages:
    14
    Tyler93,

    Do you recall what your shop did to fix your ABS problem. My rig has been in the shop for a week now and they have been working on trying to find out what was wrong with the ABS for the last 2 days. HEEEELLLLLLLPPPPPPPP.
  15. toojayzee

    toojayzee

    Messages:
    473
    Location:
    Emerald City
    ABS Sensors arent meant to be submerged in grease. Mine is, I cleaned the sensor. Question is, how much grease is supposed to be in the knuckle ?
    The FSM shows a hand smearing grease on the outside of the birfield. Mine is absolutly packed with grease, all over the reluctor ring as well. So just cleaning the sensor isnt going to fix my problem.
  16. timer00

    timer00 Just another LC driver

    Messages:
    1,207
    Location:
    NEPA
    I just finished my first knuckle job yesterday and I filled the cavity up to just before the ABS hole and cleaned my sensors all up and did not have issues after the test drive. I remember reading someone saying fill up the cavity to just before the ABS to hopefully avoid problems.
  17. FZJDoc

    FZJDoc

    Messages:
    85
    Location:
    Little Rock, AR
    I can't see the photos from the original post now.
    Anyone have a pic of what an ABS sensor is supposed to look like?
    My light is always on and code shows a left front.
    I took it out and it didn't look bad, with just some grease on it.
    What goes wrong with these things?
  18. toojayzee

    toojayzee

    Messages:
    473
    Location:
    Emerald City
    I cant speak for everyone but mine was damaged by the birf


    [​IMG]
  19. Jack G. Nichols

    Jack G. Nichols

    Messages:
    98
    You have to buy the two sensors in pairs, comes with a harness, really easy and well engineered, of course.

    Clean the sensors, of course, but look carefully for cracks in the sensor. Be sure to pull the sensors before you pull the birfs, or you will dink something up.

    Also check your harness that runs along the left control arm on my rig. I had to replace the whole thing because a rock smashed the harness wire - would not work with my try to fix it.

    Connectors not making good connections can cause problems. Take them apart and clean them, then pack with dielectric grease.

    I ran without ABS (pulled fuse) until I was sure I had to have it. Works fine without ABS. Insurance liability?

    I paid about $200 ten years ago - maybe more now. Cdan is the man.
  20. FZJDoc

    FZJDoc

    Messages:
    85
    Location:
    Little Rock, AR
    Thanks for the photo toojayzee. Mine didn't seem to have anything the matter with it and certainly not broken off like yours. I'll post a pic of mine next time I remove it for comparison.

    ^Jack, I am aware of the expense. That's why I'm trying to figure out what the hell goes wrong with them so maybe I can just clean something up and get it working. Thanks for the "check connections" tip.
    I'll run through everything again and make sure I haven't missed something simple.

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