As I enter month two of D2 ownership, I think I've identified all the botch-job repairs the previous owner(s) have done. The major ones have been corrected, and I'm finally on a quest to remove all the warning lights. SLS was reinstated a few weeks ago, but the ACE light remains.

The PO indicated that the ACE system was working until sometime during his ownership. The pump started leaking, so he removed it. He did source a replacement pump from a junkyard truck, but never installed it. If the pump was removed and nothing else was touched, is there any risk of other component damage? I figure it's been this way for 2-3k miles. I figure this is akin to driving with no swaybars whatsoever - something I don't care to experience for much longer.

Based on what I've read in other ACE-related posts, my understanding of the general process is as follows:​​​​​​

1. Clean reservoir and exposed lines as best as possible
2. Install ACE pump and connect lines
3. Fill reservoir with CHF 11S fluid and bleed ACE pump by hand
4. Install new belt
5. Am I missing anything?

Once done, can I just run it and see what happens? I do have a Nanocom, but I'm unfamiliar with the bleed programs or process for ACE. Any input is greatly appreciated. Thanks!

 

It should be a self bleeding system, and if nothing was disabled via Nanocom or the ACE ECU wasn't unplugged it should work. Is it an amber ACE light or a red ACE light? With a Nanocom you can calibrate the yaw sensors.

 

Just the amber light. I got a flashing red one today real quick after cycling the key a ton while lubricating the ignition cylinder, but it's back to amber again. Plenty of error codes on the Nanocom, but I suspect it's not happy with no system pressure.

Good to know - I'll just hook it up and see how it goes.

 

I've never recommissioned an ACE system, but the one thing I'd watch out for ... are the lines that attach to the pump capped off ? (with the little plastic/rubber caps you can buy at auto parts stores or new pumps / hoses come with). The one thing I'd be worried about would be any debris that may have gotten into those lines. I have always read and heard that the ACE system (valve body, rams, etc) are very sensitive to grit / contamination.

But if it were me, I'd probably just hook it up and see if it works nonetheless if I was satisfied the lines stayed clean.

And then of course, hopefully it was indeed the pump that was the problem! (and not another issue the prior owner tried to fix by removing the pump)

Either way, ACE rocks I'd get it working, you'll like it. I have it on 2 D2's... love it, and it's on my must list for any new Disco's I'd buy.

 

Naturally the lines were left uncapped. I've decided nothing the PO did was worthwhile at this point, but I'll spare the ranting. Let's just say a door panel shouldn't be attached with wood screws when the proper clips are less than 20 cents each.

I figure I can at least remove the hoses that connect to the reservoir and give them a good clean, or just replace them. At a minimum that should also give me a decent idea of the condition of the other exposed lines. The pump recirculates the fluid constantly, I'd assume? My plan was to run it for a few minutes, extract the fluid from the reservoir, replace, run again, repeat, etc. If it seems to work ok and nothing else leaks, then I can splurge on a new filter for the valve block (maybe two depending on how the first one comes out). Wouldn't be surprised if it's ever been changed. Almost all the parts on this truck are original.

I'll give it a go in the next few days if it finally cools off here. 110 in the driveway is not fun for prolonged periods.

 

I hear you on working on a vehicle in the hot sun. BTDT! Yep the fluid constantly circulates (quite rapidly...).

I forgot about the filter on the valve block, I'd change that too. Note if your Disco has been exposed to salt/corrosion apparently they can be tough to remove although I've never had an issue with them corroding onto the valve body on the 2 I've changed over the years. (but I'm west coast / non salt states).

I'd use genuine LR ACE/PS fluid that's spec'd for these trucks btw. Others use other fluids and I've read the reasons, but I've always only used the genuine (pricey tho) stuff and never had a power steering or ACE issue (famous last words I'm sure).

 

Pentosin CHF 11S works really, really well in these trucks. Yes, it's pricey, but it comes highly recommended. Since the power steering and ACE systems share the same fluid, it doesn't pay to try to cut corners.

The Nanocom has a testing process for the ACE system, once you get the system reinstalled and bled. You sit in the truck with the engine running and enjoy the ride as the rams physically throw the vehicle around. It will definitely confirm that you've got everything working.

 

Aside from a year in Japan (?) it's been in the UT, CA and AZ desert it's whole life, so no corrosion here.

I've been torn on the fluid choice. Lots of people seem to recommend the CHF 11S with great results, but I do like sticking to the mfr specs. I always spends way too long researching the correct stuff to use for any given system. My first oil change was delayed two weeks because of it . I've read the AC Delco Cold Climate is cross referenced as the same fluid by Texaco, so I may go with that. Given how much I'll likely be flushing out and exchanging at first, the LR fluid may be a little pricey.

 

Good to know. That seems like a good indicator for total system functionality. I'll give it a go once I'm comfortable with the cleanliness of the fluid in the system.

 

I too am a total fan boy of ACE. Once you get it working, you’ll love it, but it can be quite pricey to sort out.

DEFINITELY change out the filter.

From my experience and some assumptions I’m making based on what has been presented:
- I’m assuming while the system was not in use, they just put a non ACE serpentine belt in to bypass the system? If so, WOOHOO as that will have helped keep from buggering up other components
- Everyone is spot on with the fluid recommendation and be sure to try and flush it when you do the filter. You may want to go the extra mile and actually pull the lines and flush them individually, but BE CAREFUL as the hard lines can get buggered and I can’t even imagine the hassle and cost of replacement- let alone finding them.
- If you don’t have a Nanocom, get one and do the procedure that has been suggested. The Nanocom is invaluable and stupid simple to do a lot of very specific things on a D2.
- Do a very thorough inspection of all the lines and connections- pay close attention to the rams on the sway bars.
- Study the system in the Rave and get some ideas on function and what you should see. There are some good videos on YouTube demonstrating it too.

Like I said, I love the system, but have moved to ‘04s where finding ACE is truly a unicorn, so I’ll suffer without it. I might try to find another in the future with it.

Here is a pic of the system in general: