ACD Pump issues, what are my options?
Mar 1, 2018, 01:24 PM
#1
Evolving Member
Thread Starter
ACD Pump issues, what are my options?
Hey guys, new Evo owner here. Just picked up my new to me 9 MR and am loving it so far, however, turns out I have the annoying "all 3 acd lights on" issue... 
I've been doing some research here and it sounds like the acd pump is going to need to be rebuilt/replaced. I already went through all of the normal troubleshooting methods of checking the ABS wiring for damage (not likely the cause as the wiring seems ok and I don't get any ABS lights on the dash), acd fuse on the positive battery terminal (its good), holding the gas pedal with key in the on position to cycle pump (I can hear the pump working but it doesn't slow down or stop. From what I understand this means the pump is working but is not building enough pressure. I also get the click sound from the relay and then all 3 lights come on). I haven't pulled the acd codes yet though. Seems like the only way to do this is to take it to the dealer or use a paperclip to "bridge" pin 1 and 4? Is this on the OBD2 port or acd ecu port? And what exactly is "bridging" the pins? Literally just straightening out a paperclip and sticking one end into pin 1 and the other into pin 4? Is that safe lol? Sorry I know next to nothing about electrical systems. Also I noticed that sometimes when its cool out in the early mornings it wont give me the 3 lights issue at all but always happens right away when its hot out during the day. Has any body else experienced this? Should I start by trying to bleed the system with fresh fluid first to see if that helps it? Is it possible to remove the pump from the car and still drive around with no issue or will that damage the acd or cause fluids to leak out of the acd to pump connections?
Assuming that the pump needs rebuilt/replaced, what would you recommend for rebuild kits or used/refurbed pumps? I see a few on ebay but I am always wary of buying from ebay.
I've been doing some research here and it sounds like the acd pump is going to need to be rebuilt/replaced. I already went through all of the normal troubleshooting methods of checking the ABS wiring for damage (not likely the cause as the wiring seems ok and I don't get any ABS lights on the dash), acd fuse on the positive battery terminal (its good), holding the gas pedal with key in the on position to cycle pump (I can hear the pump working but it doesn't slow down or stop. From what I understand this means the pump is working but is not building enough pressure. I also get the click sound from the relay and then all 3 lights come on). I haven't pulled the acd codes yet though. Seems like the only way to do this is to take it to the dealer or use a paperclip to "bridge" pin 1 and 4? Is this on the OBD2 port or acd ecu port? And what exactly is "bridging" the pins? Literally just straightening out a paperclip and sticking one end into pin 1 and the other into pin 4? Is that safe lol? Sorry I know next to nothing about electrical systems. Also I noticed that sometimes when its cool out in the early mornings it wont give me the 3 lights issue at all but always happens right away when its hot out during the day. Has any body else experienced this? Should I start by trying to bleed the system with fresh fluid first to see if that helps it? Is it possible to remove the pump from the car and still drive around with no issue or will that damage the acd or cause fluids to leak out of the acd to pump connections?
Assuming that the pump needs rebuilt/replaced, what would you recommend for rebuild kits or used/refurbed pumps? I see a few on ebay but I am always wary of buying from ebay.
Mar 5, 2018, 08:53 AM
#4
Classic ACD pump failure. I wouldnt bother trying to pull the codes as what you're describing is exactly how it begins to show signs of it failing. It sounds like you've odne some research on the topic so as you put it hearing the pump run but continuing to run without changing sound tells you its not building pressure. Also, the 3 lights coming on when warm vs cold is another clue that your pump is going out; mine did the exact same thing.
Your options are to pick up a rebuild kit or try and find a used good condition pump on here facebook ebay etc. If you are looking to rebuild it yourself shoot me a PM as I have a rebuild kit that I didnt end up using.
Your options are to pick up a rebuild kit or try and find a used good condition pump on here facebook ebay etc. If you are looking to rebuild it yourself shoot me a PM as I have a rebuild kit that I didnt end up using.
Mar 5, 2018, 10:30 AM
#5
Evolving Member
Thread Starter
Classic ACD pump failure. I wouldnt bother trying to pull the codes as what you're describing is exactly how it begins to show signs of it failing. It sounds like you've odne some research on the topic so as you put it hearing the pump run but continuing to run without changing sound tells you its not building pressure. Also, the 3 lights coming on when warm vs cold is another clue that your pump is going out; mine did the exact same thing.
Your options are to pick up a rebuild kit or try and find a used good condition pump on here facebook ebay etc. If you are looking to rebuild it yourself shoot me a PM as I have a rebuild kit that I didnt end up using.
Your options are to pick up a rebuild kit or try and find a used good condition pump on here facebook ebay etc. If you are looking to rebuild it yourself shoot me a PM as I have a rebuild kit that I didnt end up using.
Mar 5, 2018, 11:05 AM
#6
No issues pulling the pump off and driving the car around while you repair it. The pump enables the system to be pressurized which controls the lockup of the center diff. Without the pump your center diff just operates as if its open the entire time. It will not cause damage to the system but will not handle as well as it can with a functioning pump. Its really no different than how it stands now with a faulty pump.
One thing that I would recommend and its something that I did was if you plan to drive around without a pump, put some sort of rubber cap and zip tie on the end of the line so the remaining fluid doesnt continue to drip out and it'll also keep it from having dirt and grit entering the system.
As far as getting the pump apart sounds like you'll more than aware of what you could run into. Only one way to find out however! Get the pump apart and get it it. And like I said I have a rebuild kit so if youre planning on buying one PM me lol!
One thing that I would recommend and its something that I did was if you plan to drive around without a pump, put some sort of rubber cap and zip tie on the end of the line so the remaining fluid doesnt continue to drip out and it'll also keep it from having dirt and grit entering the system.
As far as getting the pump apart sounds like you'll more than aware of what you could run into. Only one way to find out however! Get the pump apart and get it it. And like I said I have a rebuild kit so if youre planning on buying one PM me lol!
Mar 11, 2018, 10:37 AM
#7
Evolved Member
So when the ACD pump fails will the center differential lock and it would still engage all 4 wheels ?
Experiencing the same issue but the rear wheels are not getting the drive. all 3 lights are on.
Experiencing the same issue but the rear wheels are not getting the drive. all 3 lights are on.
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Mar 11, 2018, 10:49 AM
#8
When the ACD fails, your car will act like an open center diff.
Sometimes your able to rebuild the pump and sometimes your not. My first Evo which was a IX, the pump failed at around 38K miles. At that time there was not a rebuild kit, but it was so corroded I couldnt take it apart without ruining it further. Road salt really destroyed it. I ended up converting it to non ACD tcase .
This is why I dont like ACD and now own a non ACD southern evo 8 that never seen snow/salt.
Sometimes your able to rebuild the pump and sometimes your not. My first Evo which was a IX, the pump failed at around 38K miles. At that time there was not a rebuild kit, but it was so corroded I couldnt take it apart without ruining it further. Road salt really destroyed it. I ended up converting it to non ACD tcase .
This is why I dont like ACD and now own a non ACD southern evo 8 that never seen snow/salt.
Mar 12, 2018, 08:13 PM
#9
No issues pulling the pump off and driving the car around while you repair it. The pump enables the system to be pressurized which controls the lockup of the center diff. Without the pump your center diff just operates as if its open the entire time. It will not cause damage to the system but will not handle as well as it can with a functioning pump. Its really no different than how it stands now with a faulty pump.
One thing that I would recommend and its something that I did was if you plan to drive around without a pump, put some sort of rubber cap and zip tie on the end of the line so the remaining fluid doesnt continue to drip out and it'll also keep it from having dirt and grit entering the system.
As far as getting the pump apart sounds like you'll more than aware of what you could run into. Only one way to find out however! Get the pump apart and get it it. And like I said I have a rebuild kit so if youre planning on buying one PM me lol!
One thing that I would recommend and its something that I did was if you plan to drive around without a pump, put some sort of rubber cap and zip tie on the end of the line so the remaining fluid doesnt continue to drip out and it'll also keep it from having dirt and grit entering the system.
As far as getting the pump apart sounds like you'll more than aware of what you could run into. Only one way to find out however! Get the pump apart and get it it. And like I said I have a rebuild kit so if youre planning on buying one PM me lol!
Mar 13, 2018, 06:43 AM
#10
Evolving Member
Thread Starter
im suspecting my pump is faulty coz there is no sound when i turn the key with the gas pedal test but the acd didnt show any error (normal 1 light instead of 3 lights). is there any sound we should take note of while driving? I have this weird sound coming while driving on low gears at low speed. I have checked the gb and clutch are all okay. am on ats twin metal plate btw.
Mar 13, 2018, 09:17 AM
#12
Evolving Member
Thread Starter
Some tips:
There is a diy here that explains the step by step process of removing/reinstalling the pump https://www.evolutionm.net/forums/ev...placement.html but theres a couple things I did differently that should make it easier: It says to remove the pump assembly with the black bracket that bolts to the chassis. I didnt see why that was necessary especially since this would also require removing the intercooler pipe so I just unbolted the pump from the black bracket and wiggled the pump out by itself. Use penetrating oil especially on the 14mm hardline connection that runs under the intercooler, that will be the hardest to break loose but be careful when removing the pump because you will need to maneuver the hardline around the intercooler pipe and pump bracket.
Mar 14, 2018, 07:14 PM
#13
The pump can be hard to hear from inside the car, I thought mine wasn't working either until I had someone do the gas pedal test while I listened at the front of the car. Best way to be 100% sure is to have someone do the gas peddle test while you listen for the pump at front of car with the hood popped or visa versa. If it is working properly, you will hear the pump whine at first then start to slow down and get quieter until it stops after about 10 - 15 secs. If the pump continues to whine without slowing down then it is not building pressure and you will hear the relay click and the 3 lights will come on. Sounds like it must be working if you're not getting the 3 lights error or any abs error lights, maybe you just couldn't hear it. And I don't think the pump could make any noises that you would be able to hear while driving unless it was on its last leg getting ready to crap out maybe.
My intuition tells me its the clutch, because the sound appear after few few k miles.
Mar 14, 2018, 08:17 PM
#14
I just removed the pump from the car over the weekend so that I could try to rebuild it myself eventually (you can get a rebuild kit for $90-105). Not hard to get it out really, pretty straight forward.
Some tips:
There is a diy here that explains the step by step process of removing/reinstalling the pump https://www.evolutionm.net/forums/ev...placement.html but theres a couple things I did differently that should make it easier: It says to remove the pump assembly with the black bracket that bolts to the chassis. I didnt see why that was necessary especially since this would also require removing the intercooler pipe so I just unbolted the pump from the black bracket and wiggled the pump out by itself. Use penetrating oil especially on the 14mm hardline connection that runs under the intercooler, that will be the hardest to break loose but be careful when removing the pump because you will need to maneuver the hardline around the intercooler pipe and pump bracket.
Some tips:
There is a diy here that explains the step by step process of removing/reinstalling the pump https://www.evolutionm.net/forums/ev...placement.html but theres a couple things I did differently that should make it easier: It says to remove the pump assembly with the black bracket that bolts to the chassis. I didnt see why that was necessary especially since this would also require removing the intercooler pipe so I just unbolted the pump from the black bracket and wiggled the pump out by itself. Use penetrating oil especially on the 14mm hardline connection that runs under the intercooler, that will be the hardest to break loose but be careful when removing the pump because you will need to maneuver the hardline around the intercooler pipe and pump bracket.
Mar 15, 2018, 06:05 AM
#15
Evolving Member
Thread Starter
I had someone to help me with this test. no sound whatsoever. my pump is located under the boot not sure why maybe due to JDM version. The reason why i ask about weird sounds because im having this whine or bearing sound while moving off gradually or decelerate slowly. it goes off when i go fast. went thru few workshops, got different opinions e.g gb broken, clutch bearing, transfer case gone. acd pump spoilt.
My intuition tells me its the clutch, because the sound appear after few few k miles.
My intuition tells me its the clutch, because the sound appear after few few k miles.