KDSS is evil..

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:) So ive read the Thousand threads over the years about KDSS and the problems associated with loosening the bolts but I never thought I would have that issue having a truck that's only been in the Southeast its entire life... WRONG!!
So I'm finally putting my lift on, I'll let the bolts soak overnight..
Can't remember if anyone has tried Heat before loosening? Obviously there would be an issue with overheating the fluid but...
 
If you've read the threads - you'll know that your KDSS system is laughing at you - if you think that an overnight soak is going to break them free! ;)

I wrote up a thread about breaking them free - and my system looked like it was drug up from next to the Titanic. Patience, Kroil (penetrating oil) and a little wire brush and a little tapping will work....but I hit them a few times over the course of a week or so....

Good luck!
 
If you've read the threads - you'll know that your KDSS system is laughing at you - if you think that an overnight soak is going to break them free! ;)

I wrote up a thread about breaking them free - and my system looked like it was drug up from next to the Titanic. Patience, Kroil (penetrating oil) and a little wire brush and a little tapping will work....but I hit them a few times over the course of a week or so....

Good luck!

This. I did this over the course of two weeks. Penetrating oils over and over. Wire brush the hex heads and all around it. Multiple times. Also used a pick to trace all around the head. More penetrating oil. More patience. And tapping. Then a ratchet with an extension and a new bit. This all worked for me. Best of luck!

Guy
 
Or LPS3 if you want something specifically designed to inhibit corrosion and makes a lot less of a mess.

@silverhorse get a very high quality bit if you aren’t already using one. Think snap-on/matco/etc. 3/8” drive, not 1/4. Use a pick to dig any scale or corrosion out of the hex heads before trying to loosen. Apply upward force on the ratchet when trying to loosen. If you use extensions support the head of the ratchet so you aren’t bending the bit/extension, all force is going into twisting the bolt. If you already know all these details good, just making sure.

And what they said about penetrating oil, patience, and tapping.

I do think a fair bit of heat is ok. The fluid is oil based and under a lot of pressure so boiling/cooking it wouldn’t be a problem, your issue would be harming the o-ring on the bolt, but it is pretty far up inside the valve. You’d have to put a lot of BTUs into the whole system to heat it enough to melt the oring. I seem to remember someone having their severely rusted bolts welded on and they came loose easily, which isn’t much surprise because this is a great method to loosen seized ones. But, quite a few people report hearing with a torch not working to help free them. Maybe they were being too gentle.. one problem with using heat to loosen frozen bolts is there is a lot of “feel” that goes into how much is just right vs too little or too much..
 
Oh, and once you do get them loose, back them out three turns exactly and put some anti-seize on the threads you can see. Then run them in and back out a couple times to distribute the stuff.

Final torque is 10ft/lb. I prefer an in/lb wrench at 120 for these, personally.
 
Someone just posted a cutaway shot of the internals. There is a O ring seal in there also as it relates to heat
 
Someone just posted a cutaway shot of the internals. There is a O ring seal in there also as it relates to heat
Yeah, that was me. I don't know what material they used for the o-ring but it likely wasn't designed for much heat.. and still, I think you'd have to put a lot of heat into the thing to cause problems. It is a fair sized chunk of iron.

Again, the problem is knowing how much is too much vs just right. And the significant consequences if it goes wrong. KDSS system depressurization, pull the screws, new o-rings, and refill/bleed. Keeping in mind how hard it is to find a dealer that has the tool and knows how to use it.

I'd definitely try all of the stuff above before resorting to a torch.. but if it were mine and that stuff didn't work, and with my past experience working metal, the torch would become an option.
 
Here it is again, straight from the TIS:

Capture 1.PNG


Capture 2.PNG
 
Patience. I wouldn't apply heat for fear of damaging the KDSS cylinder but some folks have welded a larger nut to the head of the screw which can help break it loose as well.

re: preventing this - I bought my truck in Jan 2016 from Houston and had it shipped to Chicago. I've been slathering marine grease on mine since fall 2016 once a year around November when I hit the rest of the undercarriage with fluid film. I just did it yesterday afternoon again... wiped off the old grease first just for grins and the KDSS screws are still pristine underneath. (FF does an ok job slowing down the rust but unless you apply it every couple months in the winter it won't completely stop surface rust on the frame welds or suspension bolts).

I don't remove the KDSS shield or anything, I just glob some marine grease on my finger and stuff it up in the hole and slather it around. Repeat for the other hole. The shield seems to do a good job keeping the road salt from spraying it off.
 
Patience. I wouldn't apply heat for fear of damaging the KDSS cylinder but some folks have welded a larger nut to the head of the screw which can help break it loose as well.

re: preventing this - I bought my truck in Jan 2016 from Houston and had it shipped to Chicago. I've been slathering marine grease on mine since fall 2016 once a year around November when I hit the rest of the undercarriage with fluid film. I just did it yesterday afternoon again... wiped off the old grease first just for grins and the KDSS screws are still pristine underneath. (FF does an ok job slowing down the rust but unless you apply it every couple months in the winter it won't completely stop surface rust on the frame welds or suspension bolts).

I don't remove the KDSS shield or anything, I just glob some marine grease on my finger and stuff it up in the hole and slather it around. Repeat for the other hole. The shield seems to do a good job keeping the road salt from spraying it off.
The KDSS screws may appear pristine, but do they loosen? Have you tried?
 
The KDSS screws may appear pristine, but do they loosen? Have you tried?
I've cracked them before to put the lift on, and again to swap the rear springs. I didn't do it this year but I'm confident they will open without issue.
 
^ And that is what REALLY counts!
 

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