There have been several threads about the ACD lately (one was mine) which has made me wonder what the percentages were. So, has your Evo had a problem with the ACD i.e. all three tarmac, gravel, snow lights on at the same time?

 

My ACD pump died last year (or the one before? can't remember). Got a used one from someone in california and that one's been going strong since, however I'm starting to see surface corrosion on it. Considering rebuilding it right now before it fails then adding some kind of protection around the pump body.

 

I believe it's a common problem with Evo's. Mine went and with roughly 20k miles. I think it's because it's open to the elements so it just corrodes away. If I remember correctly though, non US Evo's have the ACD pump located elsewhere.

 

I haven't had problems per say, just all ACD lights coming on at once. The problem I found is the fluid was low nearly bone dry (not used to ACD because my previous evo was an 03). So I replaced it then we bled the valve after and a bunch of air came out then put more factory fluid in. Since then I've noticed a difference in how the car corners in a positive way.

Usually the lights will come on for a bad pump or simply if the fluid is low and there is air in the line. I recommend starting with the cheapest solution and going from there if you're having ACD issues.

 

I don't get it...87 views but only 6 votes?

 

0 problems in almost 9 years daily driven daily and road raced a bit over that time too. I am the original owner and have always maintained the car on a regular schedule by checking the fluids as well as having it looked at by shops that have dealt with Evos for years (the two in my sig). I think a lot of the issues some folks have are either due to lack of maintenance somewhere in the car's history or having folks not familiar with the ACD working on it (and sometimes a combination of both).

 

There's no ACD-related maintenance other than checking the ACD fluid level. Not sure how someone could manage to botch that. Also has nothing to do with pumps getting corroded.

 

Bingo...

Lets be honest, Mits corrosion performance is one of the worst in the N.A market.

... but my car was 100% stock and within 35k miles had the TC fail and ACD pump
Mits made 0 profit on these vehicles from warranty I'm 99% certain

 

It's them '03-'04 Evo 8 guys looking to see how much the 9er's suffer wif ACD

Really? You must be very lucky since corrosion is such a common issue on the 9's and the failures are generally caused by the corrosion on the pumps which burns out the motor coils. Considering you're from Quebec I find that hard to believe even. Mine was a Wisconsin car with only 38k miles when I bought it and well babied and garaged and is now housed in Michigan. While it hasn't had any issues - touchwood - for reliability, the car is 6 winters old (stays indoors in winters) and the ACD pump completely corroded last year which needed rebuilding and a custom housing.

While you're right in that the fluid level is all the maintenance the ACD itself will require, the pump failure is what causes the lights to ultimately come on. The poll says 63%, but I think it's probably 90% + of winter states owners that will see corrosion on the ACD pump.

Here's 2 threads that could help the OP:
(1) https://www.evolutionm.net/forums/to...p-failure.html

(2) https://www.evolutionm.net/forums/ev...-acd-pump.html

Hope it all works out

 

Literally two posts above someone talks about not checking that fluid until it was already dry which is more common than you would think. And corrosion does not pop up overnight...you don't park a car with the pump with 0/little corrosion and come back to find the pump fully corroded the next day. Like you yourself said, you've been monitoring the new one you have in and are staying on top of it. Yes mitsu didn't do a good job with the corrosion protection, but that's been known for a long time. You solve it the way you do which is you stay on top of it.

 

EUDM and JDM cars have the pump under the trunk, behind the left rear wheel, and it gets really bad..

as for percentage, we get lots of salt on the road and only the garage queens still have working pumps. Evo X is much worse... those last about 2 years.

Loosing fluid from the ACD tank is usually an indication of a broken diaphragm of the hydraulic actuator in the transfer case that actually pushes on the central diff locking plates.

My pump died at about 70000 km, and I just rebuilt a pump on an identical E9 with identical miles from Romania.. Also had a E9 from switzerland with about 80000 km...

 

How am I lucky? Quebec winters did indeed take a toll on mine and it died 2 years ago.

 

When you buy a new car, you dismantle it and spray it down with anti-corrosion? I call this a design defect that customers shouldn't have to deal with. And Mitsubishi continues to sell them like this today even though it is a known problem.

 

Wow it is sad to see the amount of pump failures because of corrosion...
Going to look into making some kind of protection for it ..
Any shops that sell something like the EU and JDM ACD pump boxes, but for the USDM pump location?

 

I spray mine down with Boeshield every Winter season.