So last year I had the high pressure line from the ACE pump to valve block burst. I sourced a replacement 2 piece line from England plus a couple of valve block o-ring inserts and had them shipped over. The new line installed just fine, didn’t even have to replace the o-rings on the valve block. Fast forward about a year - after an off-road drive the new line started leaking at the valve block. I figured - cool, I have new o-rings, I’ll swap the new set in and be good to go. Not so.

After replacing the o-rings with new, it leaked worse. I tried finding some o-rings that were just a little bigger and inserted them, no joy. I was down to having to order a new 2nd half of the line plus a new o-ring set - that would have cost close to $200. Not too bad, but with no guarantee it would fix the problem I looked into removing the valve block, tapping out the holes and installing new hydraulic fittings - cheaper, with parts available right here in town.

My first task was to find a place to purchase the compression fittings. The metal lines on the ACE system are 3/8. I found a shop that had some in stock - 6 are needed so I bought 8 just in case.



I then got a tap from the local tool store.



I used colored electrical tape to mark the placement of the lines and took a photo. I did the same with the electrical connections to the solenoids.





There’s a bracket holding the two lines running to the rear - loosened that as well at the two on the forward pipes. One bracket on the front is accessed from inside the engine compartment.

Removed the nuts holding the retaining plates in place. Drained the fluid into a catch pan, plugged up the lines the best I could to keep any dirt out.





There are three bolts on the side of the block holding it to the frame. Once the valve block is out I used a bolt threaded into the o-ring keeper to grab onto it so I could extract it.



Once all the keepers, o-rings and spacers were removed I removed the solenoids making sure to save the large o-rings - internal and external.









I used zip-locks to keep everything clean and in order.



Then I removed the filter and transducer bagged them.



Now the really nerve-racking point of no return part. Drilling out the holes for the tap.

I got focused on what I was doing and forgot to stop to take pics. The drilling and tapping create a ton of filings. This is why removing everything from the valve block is necessary.
I used a ton of break cleaner spray bottles and after that a garden hose to make sure there were no filings left inside the block to come back and bite me later. The thing was clean as a whistle when I was done.



I ended up using a grinder on the sides so I could get a wrench on the fittings at the bottom. They would disappear into the o-ring retainer holes when tightening and
I wanted to have a wrench on the fitting while cranking down on the compression nut.
I used a sealing locktite on the threads and reinstalled the solenoids, filter and transducer.



All back together.







Refit the valve block to the truck. The rear lines I was able to push back just a bit and install them.
The front lines I ended up cutting down a little bit in order to avoid bending theml. The metal knuckles fit almost flush with the compression nut.



After everything is secure and back in place, refill with fluid and find a parking lot to do figure 8’s in for a while to get the air out of the system.

It’s been about 2 months since I did this job - I did have a leak after getting it all back together from one of the solenoids on top of the valve. Not a huge leak, but enough to worry about. I parked it and in a few days I was all set to remove the block again and try and find new o-rings for the solenoid, but I decided to take it out one more time and check for leaks. Lucky me - no leaking. I figure the o-ring must have dried out a little and a few days back in place it swelled back up and stopped leaking.

Lessons learned. I think if I were to do this job again, and I probably will since the wife’s rover has ACE on it too, I’d use a BOSS type hydraulic fitting. The block side has a chamfer for an o-ring - needs a sealing face and has a straight thread. I’m no machinist, so I’d have to take the valve block to a machine shop and have them do the work. I think it’d be worth the extra cost for the peace of mind knowing that it had an o-ring seal and not just threads. Plus, my work with the grinder was just sad and ugly and they could make it pretty.

 

Very nice write up! Would you like me to make it a Sticky? Just let me know

 

Hey that'd be cool if you think it's worthy!

Also I forgot to add to the post that the whole thing cost me about $60

 

My truck doesn't have ACE but this is an awesome mod / fix for this system!

 

I am having ACE issues, mainly leaking at the valve block and electrical issues. Found a company in England, Design and Development Engineering, LTD, that offers a total rebuild/redo on the ACE valve block. I plan to order one in the next few weeks and install. They then will take your old valve block and refund $$ as a core charge. I'll post something when I do the swap.

https://www.designdevelopmenteng.co....ded-p110170661

Great write up, T-Rex! Definitely make this a "sticky"!

 

Nice write up, you have managed to inspire me to do something similar. I have found the following hydraulic fittings. do you think they will work?