@jpsfj60, have you attempted the ACSD delete yet? I'm wondering whether the replacement hex key bolt size for the backing plate (post-ACSD removal) that the Radd Cruisers representative suggested is correct (6mm x 1.0), back on post #11 in this thread?
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Thanks @jpsfj60! Anything you contribute will help out others (and myself) a ton.
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- #25
I am working on removing the ACSD (thermo wax) now. Just took a quick break to look at the pics again.
Will post how this removal went as soon as I am done and my 81 is running again..
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- #26
So here is what I learned doing this thermo wax removal.
1st remove the 2 throttle linkage arms. I then removed the 3 5mm bolts that held my cruise control and tranny cable
bracket on. After that I took the 12mm bolt that held the thermo wax linkage on where those 2 big springs on.
I took the linkage and the springs off. You can now get to the top 5mm bolt of the thermo wax. After that I just broke
the top and bottom 5mm bolts loose for the ACSD.
hose that comes off the block. The clamp was faced downward and I had to unplug the green sensor that is right next to
it so I could work the clamp around to where I could work with it.
So now it started raining right while I was about to take out the ACSD. So I just tightened up those 2 5mm bolts and left
everything for tomorrow to finish up. So now all I have to do is take out the ACSD (thermo wax) and loop the coolant lines
together with a new 3/8in hose. Will find out how long the bolts are that hold that acsd to the IP tomorrow. From what I have
read I should be able to use the tranny linkage bracket bolts for the block off plate. If not then I will just go to my local true
value and get new bolts that are the correct length.
After that I was told to top off coolant at the rad and to pump the plunger on top of my fuel filter. Also was told to hold my
pedal to floor for the 1st start up after this job is done. The reason for that is cause of the diesel
fuel you loose when you take out the ACSD from the IP.
Will let you know how everything goes tomorrow morning.
1st remove the 2 throttle linkage arms. I then removed the 3 5mm bolts that held my cruise control and tranny cable
bracket on. After that I took the 12mm bolt that held the thermo wax linkage on where those 2 big springs on.
I took the linkage and the springs off. You can now get to the top 5mm bolt of the thermo wax. After that I just broke
the top and bottom 5mm bolts loose for the ACSD.
hose that comes off the block. The clamp was faced downward and I had to unplug the green sensor that is right next to
it so I could work the clamp around to where I could work with it.
So now it started raining right while I was about to take out the ACSD. So I just tightened up those 2 5mm bolts and left
everything for tomorrow to finish up. So now all I have to do is take out the ACSD (thermo wax) and loop the coolant lines
together with a new 3/8in hose. Will find out how long the bolts are that hold that acsd to the IP tomorrow. From what I have
read I should be able to use the tranny linkage bracket bolts for the block off plate. If not then I will just go to my local true
value and get new bolts that are the correct length.
After that I was told to top off coolant at the rad and to pump the plunger on top of my fuel filter. Also was told to hold my
pedal to floor for the 1st start up after this job is done. The reason for that is cause of the diesel
fuel you loose when you take out the ACSD from the IP.
Will let you know how everything goes tomorrow morning.
I don't really think that is necessary.
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- #28
Sorry was told to do that after it shuts off from the air in the fuel system. Will let everyone know
if it shuts off like my buddy says. He is a trained diesel tech and have built many of the best diesel
engines in the world. THE CUMMINGS!!! Wish this 81 had a 6BT in it instead of this 1 HDT. Wouldn't
be doing this delete if it was a Cummings. I would be doing a Denny T top hat delete that adds 90 HP
with just one simple mod!
That, and the killer dowel pin, lol!
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- #30
Never had any issues with that killer dowel pin problem with any of my 6bt's. That is a simple
fix also on those motors. Reminds me a lot of this ACSD problem that you could have on these 1 HDT's.
Now that it has stopped raining this morning I will go out and pull the thermo was out and put the block off
plate on. Then loop the coolant lines. I think I will loop the lines 1st then deal with the block of plate install.
Not looking forward to getting the clamp tight on the bottom coolant line that is right next to that green sensor.
Will let everyone know how this goes.
The KDP is very similar to the ACSD actually, danger lurking within, lol. Good luck this morning!
- Thread starter
- #32
Finished this ACSD removal up this morning. I used a medium plastic container to catch the fuel from the side of the IP. That
worked very well. Take the top coolant line off the back of the thermo wax and put a bolt into it to plug it. Now you can take the bottom
coolant line off at the engine block. Almost no mess at all. As soon as you take that line off slip on your new hose. Make sure you have
your clamp in the right spot so you can tighten it get it back on. I used new clamps. I also capped the back of the thermo wax when I
took that line off so I didn't have coolant dripping while I removed this ACSD. Now take the other line off the top of the engine block and
put the new hose on up there to complete the coolant loop. Tighten both clamps. That was the only pita part of this job.
Now loosen the 2 5mm bolts that hold the ACSD on. Make sure you plastic container is wedged underneath it. Remove the ACSD.
Take out the old O ring and put your new O ring in place. Now you are ready to bolt your new Block Off Plate on. You have to use the
bolts that came out of the tranny cable bracket or get newer longer bolts. I also used a SS washer behind the 5mm bolts to put the block
off plate on. You can use the bolts that came out of the ACSD to put the tranny cable bracket back on. Connect you linkage rods back up
and you are almost done.
Pump you fuel filter plunger a couple of times and fire her up. CHECK for leaks at block of plate and where the coolant lines are.
I had no issues when starting her back up for the 1st time.
Good luck HillCountry! If you have any questions just ask. Job wasn't that bad at all. Just take your TIME doing it.
- Thread starter
- #34
There is no reason to advance the IP. That is what Radd Cruisers told me also. I just got back from my 1st test drive
and there is a huge difference in the way it acts and idles!! Idles lower than it did before and idles right where it should
with the AC turned on... Now I don't have to worry about metal shavings going thru my IP if there is failure with the
ACSD mechanism. Was told by another cruiser shop in Canada that I don't need this thermo wax at all in any way shape or form....
DELETE IT IF YOU STILL HAVE IT!!!!!!!!!
Thanks @jpsfj60!! Did you take any photos as well? If not, no worries, your explanation seems great without any photos. I have a manual (5-speed) and no cruise control, so I won't have some of the items you have to remove to get to the ACSD. I'm also wondering whether I should just go and buy new 5mm hex key bolts of the right length for attaching the backing plate. Do you remember the length and size so I can go to the hardware store and get some? I don't have the luxury of assuming that I'll have the right length 5mm hex key bolts since our HDJ81 is our only vehicle and our daily driver 
If you know a size/thread type for the 5mm hex key bolts that should be used to hold the backing plate on, that'd be great!
The coolant line hose how-to portion is great as well...I was wondering what the order should be so that I don't lose a bunch of coolant and make a mess. Thank you for posting your experience on the ACSD removal...huge, huge help!
I will try and add to this thread with photos when I get around to my ACSD removal. I have the new o-ring and backing plate, along with about 16 inches of 3/8 inch coolant hose and two new clamps (for looping the coolant lines after the ACSD removal).
If you know a size/thread type for the 5mm hex key bolts that should be used to hold the backing plate on, that'd be great!The coolant line hose how-to portion is great as well...I was wondering what the order should be so that I don't lose a bunch of coolant and make a mess. Thank you for posting your experience on the ACSD removal...huge, huge help!
I will try and add to this thread with photos when I get around to my ACSD removal. I have the new o-ring and backing plate, along with about 16 inches of 3/8 inch coolant hose and two new clamps (for looping the coolant lines after the ACSD removal).
The Radd Cruisers ACSD delete kit also included some dowels to space out the bracket from the pump where the ACSD used to occupy, although it took a bit of pondering to figure that out as the kit didn't include any instructions.
- Thread starter
- #37
Thanks @jpsfj60!! Did you take any photos as well? If not, no worries, your explanation seems great without any photos. I have a manual (5-speed) and no cruise control, so I won't have some of the items you have to remove to get to the ACSD. I'm also wondering whether I should just go and buy new 5mm hex key bolts of the right length for attaching the backing plate. Do you remember the length and size so I can go to the hardware store and get some? I don't have the luxury of assuming that I'll have the right length 5mm hex key bolts since our HDJ81 is our only vehicle and our daily driver
The coolant line hose how-to portion is great as well...I was wondering what the order should be so that I don't lose a bunch of coolant and make a mess. Thank you for posting your experience on the ACSD removal...huge, huge help!
I will try and add to this thread with photos when I get around to my ACSD removal. I have the new o-ring and backing plate, along with about 16 inches of 3/8 inch coolant hose and two new clamps (for looping the coolant lines after the ACSD removal).
I will find out the size and can tell you the length when I get home today. You will need to get new 5mm bolts that are longer cause you don't
have the transmission kick down cable bracket there bolted to the top of the IP.
This job will be easy for you. Take that 12mm nut off the ACSD and then pry the linkage and the 2 springs off. That will give you access to
that 5mm ACSD bolt and the other ACSD 5mm bolt you get to from the going thru the wheel well opening. You will need to remove the plastic splash guard to do this.
Now for the coolant hose removal. Take the top coolant hose off the back of the ACSD. Have a bolt ready to screw into the 3/8 coolant hose to plug it. Now remove the bottom coolant line from the engine block. Have your new hose with clamp ready to put on. You will only loose a pinch of coolant. Now take that top hose off the engine block and complete your loop. I also put a black vacuum nipple on the back of the ACSD so coolant would stop coming out. I also plug that bottom hose I took off 1st so coolant wouldn't flow out on stuff. Now remove ACSD. You should still have the one coolant line on the ACSD that is plugged with a bolt and the nipple on the top where the other line went. Now you can pour
that coolant out and see what it looks like....
Keep me posted on how it goes. Call me if you need to. 717-612-0619 If I lived around you I would come over and do this removal with ya!!
image of that kit ?
Don't have one, and can't find one. It was a bag with some bolts, hose clamps, heater hose, block off plate, o-ring, and sections of metal tubing (what I called dowel earlier, probably not the right word), etc.
What's the consensus on where to get the parts needed? I need a kit for my pump.