K so I was starting to have an abs light come on on the '98 uzj100 on cold mornings only (now it's cold every morning in CO) but then it would go off so I thought I would get ahead of the problem and pulled the abs code 56. So reading on here sounds like it was the booster/ accumulator so ordered one of those from cruiser parts. Also for good measure I got the 2 abs relays related to this on ebay found for $15 so why not right. Well all that done and it seems worse. I am now constant light reading the same code 56 and continuously cycling booster seeming never to get to pressure even though brakes seem to be working great. So here is where I'm stuck. Is there a special way to bleed the booster after install? What else should I check is there a switch that is not telling the booster it's at pressure? Maybe bad booster? Any ideas would be great.
Abs issue some work done but stuck? (1 Viewer)
- Thread starter viking cruiser
- Start date
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uHu
Bridgeburner
WHat did you change? Complete booster with accumulator and master, or only booster motor, or only booster accumulator?
I'm asking because if you changed the whole caboodle, there isn't that much more that can go wrong.
I'm asking because if you changed the whole caboodle, there isn't that much more that can go wrong.
- Thread starter
- #3
I changed the booster and accumulator assembly not the master
- Thread starter
- #4
ok I do not think I bled the brake booster properly. FSM is not the most clear on this. Can someone explain this with out using the SST?
Maybe a bit of ABS action will get things purged, can you find an icy/snowy carpark and lock the brakes a few times to see if that gets things cleared?
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2001LC
SILVER Star
^2x, I do remember needing to get the ABS to kick-in per FSM two or three times, but that was for bleeding fluid. Worth a try....
- Thread starter
- #7
Ok did this today and took it on a longer drive no dice. Thinking I may have to take it in to see what else it needs.
If the ABS light is on the system is usually disabled so you have to get it functional before you can bleed it that way.
Not sure how to bleed otherwise. You could try turning the part at different angles while pre-filling it with as much fluid as possible before install.
Not sure how to bleed otherwise. You could try turning the part at different angles while pre-filling it with as much fluid as possible before install.
uHu
Bridgeburner
If I understand this right, you have the abs-light on, and the code 56, and having changed booster and accumulator complete with pressure sensors.
If the booster is cycling on and off all the time, without applying brakes, it means that the pressure is disappearing somehow. Wouldn't that lead to suspecting a seal in the master? There is a service kit available.
ABS bleeding can be done using TechStream.
If the booster is cycling on and off all the time, without applying brakes, it means that the pressure is disappearing somehow. Wouldn't that lead to suspecting a seal in the master? There is a service kit available.
ABS bleeding can be done using TechStream.
APKhaos
Unfixing the unfixable
If you still have an ABS light on, you need to clear that to re-enable the ABS controller.
The clear process is specific for the early years, including your 98. The 2004 FSM is not the guide to use. Here's how to do it on your 98:
(1) Using SST, connect terminals Tc and E1 of DLC1
and remove the short pin from DLC1.
SST 09843−18020 = a short length of 12 gauge wire with spade lugs at each end.
(2) Turn the ignition switch ON.
(3) Clear the DTC stored in ECU by depressing the
brake pedal 8 or more times within 5 seconds.
(4) Check that the warning light shows the normal
code.
(5) Remove the SST from the terminals of DLC1.
SST 09843−18020
(6) Connect the short pin to DLC1.
With the ABS controller reset at least that part of the system is good to go. Sounds like the primary brake system is losing pressure, which suggests a leak or a failed master cylinder seal.
The clear process is specific for the early years, including your 98. The 2004 FSM is not the guide to use. Here's how to do it on your 98:
(1) Using SST, connect terminals Tc and E1 of DLC1
and remove the short pin from DLC1.
SST 09843−18020 = a short length of 12 gauge wire with spade lugs at each end.
(2) Turn the ignition switch ON.
(3) Clear the DTC stored in ECU by depressing the
brake pedal 8 or more times within 5 seconds.
(4) Check that the warning light shows the normal
code.
(5) Remove the SST from the terminals of DLC1.
SST 09843−18020
(6) Connect the short pin to DLC1.
With the ABS controller reset at least that part of the system is good to go. Sounds like the primary brake system is losing pressure, which suggests a leak or a failed master cylinder seal.
- Thread starter
- #11
Ok looks like I am buying the rebuild kit and giving that a try!
I am in the same boat. I think its the brake pressure sensor mounted on the master cylinder or the harness for the sensor.
- Thread starter
- #13
Did you do the rebuild already?
I only changed out the booster pump assy. I bleed the brakes, then actuated the abs multiple times by driving on a gravel road. Then bleed the brakes again. I cleaned the connector contacts and I thought that was it since it stopped for 2 days. I am going to try to check continuity in the harness next and maybe buy the sensor (89637 30050)next week. Its around $250-$300. I should have bought the whole assy.
APKhaos
Unfixing the unfixable
Hey Viking.....can you delete some old PMs - been trying to PM you but your box is full. Tks.
- Thread starter
- #16
Pm's deleted
So I cleared the fault codes and got about two days of no faults. I then got c1252 fault (Hydraulic Brake Booster Pump Motor
ON Time Abnormally Long) yesterday. So the c1256 fault went away with the booster change. The weird thing is it only happens when the truck has sat overnight and had time to get cold.
ON Time Abnormally Long) yesterday. So the c1256 fault went away with the booster change. The weird thing is it only happens when the truck has sat overnight and had time to get cold.
- Thread starter
- #18
If you figure it out please let me know I changed my booster also and it went away for a few day but when it get cold it comes back. Pissing me off
I think my issue is with the high pressure switch. The sensor stops the pump when the pressure is met. See the following:
http://www.ezdries.net/Vidpics/ATRAC/LC100 new features.pdf
I am going to open the abs cover and poke around. If I can't find it, I may buy the master + abs assy.
http://www.ezdries.net/Vidpics/ATRAC/LC100 new features.pdf
I am going to open the abs cover and poke around. If I can't find it, I may buy the master + abs assy.
APKhaos
Unfixing the unfixable
Great reference. Thanks! That one should be a stickies candidate [unless its already there, of course].
