I have purchased and received the ACD pump rebuild kit and tester which I believe was developed by kikiturbo. I wanted to identify for certain if the pump was bad before getting into the unit to do what looks like pretty good surgery based on the videos and posts.

My rub was that I have a CA car, always garaged, and the pump looks new on the outside. However the behavior I have had the last year or more was that while trying to bleed the system it just wouldn't spit out fluid or bubbles like it used in many years before. I just assumed my assistant with foot on gas pedal and key turning thing wasn't perfect and I didn't worry much about it.

I then purchased a built diff from TRE, and the car still didn't rotate as I might have expected. I started to wonder if my ACD was really doing what it should. I tried bleeding again, and again, but still it barely dribbled out fluid. Didn't seem like a lot of pressure there.

I decided the pump was not working. I also felt like the pump was free wheeling while I was bleeding it, which is that the motor is running, but the pump housing isn't producing any pressure. Time for the rebuild kit. I also ordered the tester so I could quantify a before and after pressure measurement from the unit, and figured this would make a better thread or how to on the process with some data before and after the fix.

The test however is suggesting that the pump is working fine. On the bench initially it seemed to freewheel when I had the plug installed. Then I did the test again with the gauge attached (after buying a bunch of crazy adapters) and after several tests it seems to be changing in tone, and the gauge shows pressure. Once pressure builds the pump seems to max out. You can hear it in the video and it will make the gauge rattle when it gets there. I made quick video in case it would help people see what I am talking about.

I am trying to troubleshoot if the pump is bad, or intermittently bad. If not then what other issue could I have when the punp is in the car, and how do I test or troubleshoot for that. Any thoughts appreciated.

Here you can see the pump is in good exterior condition. Again CA garaged car all its life.


Here you see the pressure with the solenoid opened. The pump is not running in this pic, the pressure is static.


Here is the video of the test and me babbling on.

 

To answer your key question: yes, a pump can go through an intermittent phase before dying. (Elsewhere I have talked about "mostly dead" pumps and "completely dead" pumps, but there aren't enough fans of The Princess Bride for that to be funny, it seems.) In your shoes, especially with the parts in hand and a pump that is already out of the car and looks like it will come part easily, I would rebuild it. Then use the Kiki tool to do a good bleeding.

 

That was friggin hilarious. I guess I am old enough to completely get that reference.
"It just so happens that your friend here is only MOSTLY dead"

Can you comment on the sound the pump makes after it gets about full pressure? That rattling sound once its pressurized in the vid. I turn if off then, because I fear without the ECU and the pressure sensor connected it could damage itself by continuing to run and try to pressurize beyond some engineered level. Or it could just be that the pump is not dead until a certain pressure and then its mostly dead.

Do we know what pressure is supposed to show on that valve for a properly working pump?

Or, is it OK to let the pump run in this 'on bench' configuration until it stops itself, or will it stop itself?

 

I'd stop at 150 psi. Too bad that the Kiki tester doesn't read the switch and turn off on its own. That would be a nice feature. Maybe add it yourself. At a minimum, put a volt-meter on the pressure switch to make sure that it makes it to whatever Mitsu thinks it should stop at.

The rattling could be a partly corroded plate. I don't have enough experience to say much on that. But that's part of why I'd rebuild it while it's out of the car.

edit: in case that first part wasn't clear, without wires on the pressure switch, I don't see how or why the pump would stop on its own

 

Where can I get this kit? Originally I was going to get it from www.acd-tuning.com but it seems like they are not selling it anymore.

 

The easiest way to test the pump is actually with it on the car itself. You turn the key to the on position and push the pedal to the floor(like you're bleeding it but dont open the bleeder) you're just going to be listening to the pump. If it runs for 3-5 seconds and then shuts off it is operating properly and is building enough pressure to shut off and sit idle waiting for the need to run again to build more pressure. If the pump runs and runs and runs for like 20 seconds and then finally shuts off from exhaustion then that means it is not building pressure and then yes it would need a rebuild. The gauges are nice and so is that testing kit but having it installed in the car and seeing how it behaves is really the best test overall.

 

Other than the fact that having it in the car means that the pump will be turned off when the pressure switch closes, I don't actually see any advantage of having the pump in the car. Can you explain a bit more?

 

Ive never had success with the gas pedal to the floor bleeding. Only drips ever since I did the clutch at 40k (now at 120k and have bled it at least 20 times troubleshooting a bad pump and installing a rebuilt one).

All you need to do is apply voltage to the pump and the solenoid. If the solenoid doesnt open flip the polarity. Pump power is obvious, black & red. I swear it will drain the reservoir in less than 30 sec if youre not paying attention and you will KNOW its bled. Wire the above circuit to a toggle switch that is within reach of the bleeder and its a one man job.

The testing kit most likely does this for you, but Im not sure if you can use it for bleeding once its installed.

 

Good idea, I will put a meter on that pressure switch to see if I can see it want to jump during a cycle.

I think I just noticed that gauge is in bar, so I am exceeding 150psi during each test. ? If that gauge is accurate. I thought initially it was in psi.


I also started this thread on my order:
https://www.evolutionm.net/forums/ev...ll-around.html
There are a couple of mentions about a transition in there, so that is what seems to be the hiccup and likely why there are no more kits listed on that site.

I used to have good success with the bleed using the gas pedal years ago. It was at least as strong as bleeding the brakes.

The tester is commented in other threads to be a great bleeder, but you will ultimately still need to bleed the line itself anyway, so you need to bleed the system when its re installed in the car. You can connect the tester then to avoid needing someone to do the key and gas pedal thing.

 

I think that 10 bar (145 psi) is the minimum for a pump to be OK. I think that the actual operating pressure is something like 16 bar (235 psi). Maybe those are the switch-on and switch-off points for the Hobbes. Sorry. I don't have my notes here. Maybe try teh google. I knew that your gauge was in bar from the reading combined with the sound of the pump.

If you can get to the pump's harness when it's in the car, I'd bleed it with Kiki's gizmo. Just make sure to get all the air out of the pump part while it's still on the bench.

 

Looks like am actually going backwards first. I took the pump apart, and as I suspected it was essentially in totally new condition. I installed the replacement plate and o rings anyway since I was in there. Very little cleaning was needed at all.

With the exception of wiping some oil off with a paper towel this is how my internals looked. The bolts just clicked off without any issue, and the whole thing unfolded like it was brand new. (I have 70k miles on my car, but in CA)





I put is all together and went to test it and go no pressure. None. I kept fiddling with the solenoid wires thinking that the solenoid wasn't opening as it did in my first test, before taking it apart. no change. I then thought the battery jumper I was using was getting low and maybe that thing is really sensitive to volts/amps. So I charged it overnight, and today, same thing. I then took my gauge off and ran a line from the outlet back into the res to 'bleed' the system. Still nothing. The pump would run, but the solenoid clicked softly, but nothing was getting through.



Now I am trying to figure out what to do next. I tried to find solenoids online, but I couldn't. How do I test if that thing is still good. I took it out, and it also looks in good shape, but it wouldn't click over as I expected on the bench. Does anyone have a spare I could use to test/troubleshoot if that is the issue? Do you know where I can get one?

Is there anything common about putting the pump back together that could have been a mistake I made. Its pretty simple in there, and I watched the video a zillion times from kiki.

 

Self bump,
Does anyone know where to get the ACD pump solenoid?

 

I was hoping to get some help, because I am somewhat stuck. I rebuilt the pump as noted above, and then couldn't get any pressure to register.

Possibly I need to bleed in a way that I am not understanding, but no matter what I couldn't get pressure. I assumed the solenoid went bad because it didn't fire. So I sourced a used junkyard pump. Unfortunately the solenoid on that pump had the plug ripped off, and it was not possible to use. I was able to test it and then confirmed that the tester from the kit was now bad. Only occasionally would the button for the ACD solenoid actual provide a signal. I took the tester apart, and jumper the connection to make sure the solenoid worked. It does, and so does the junk yard spare.

Then I pump the junkyard pump back together and tested for pressure. Nothing. I could hear the pump running and volume decreasing, and the sound of the gas building, possibly venting internally. But no pressure on the gauge. Convinced I was doing something wrong, I took the bit off of the junkyard pump and put them on my rebuilt pump. Same thing. No pressure.

I was trying to eliminate that fact that I might have done something incorrectly when rebuilding my pump with the new plate and orings. Then I put both pumps on the car's wiring harness to make sure its not some error my bench testing proess. Still no pressure for either pump.

Now I am stuck with a bunch of possibilities, but no ideas on how to prove or troubleshoot them. Only questions.

1 - What does the N2 Gas bubble container do exactly? How do that interact with the oil? How does that thing work? I know its working on the junkyard pump because during a switch of the parts it exploded oil all over me, my pops, the wall, and every tool within 5 feet! Fun.

2 - How do you properly bench bleed the system?

3 - What could I be overlooking that I am not getting any pressure at the output for either pump. I know the gauge works, because it did before, and because I retested it with the air compressor.

 

hi,

I just watched the vid... The pump in the video works ok. it produces pressure and works fine.

as for the bleeding.. you basically open the bleeder from below the ACD diff, turn on the pump motor, wait untill the pressure reservoar (black N2 bulb) gets under pressure (you can hear the pump slow down) and then you press the ACD button (or whichever button you connected to the valve) and the fluid should gush out from the bleeder. Then close the valve and wait for the pump to pump up again and repeat.

Repeat untill there is very little air coming out from the bleeder.

 

Also, the pressure gauge in the kit is intended to go to the pressure sensor port. The video is not clear in this regard as the first version of the kit came with the hose that connected to the pump outlet, like you did. That is why the hose doesn't fit. But the way it is done now is better for pump testing.