Well, I tried again today to get the lower bolt pressed out of the trailing arm. No go. I sat back and studied on the suspension for a while and decided to pull the caliper and the carrier end cap. When I did, I found out why the top bolt was backed out. The damn bolt had been stripped and the outer 1/4" of thread in the carrier was toast. With the end cap not being firmly snugged, it allowed the upper link bolt to work out with the levering action of the suspension. Now I found the cause, plus I found the caliper bolts weren't tight either.
Studied on the carrier for a bit and decided to chance a repair. An 8mm botttoming tap and a 8 x 40 replacement bolt were purchased (the original bolt is 8 x 35), opted for the extra 5mm of bolt to purchase good threads. Very careful work with the bottoming tap allowed me to restore the first 1/4" of thread and clean up the rest. Slow tedious work, but I saved myself from having to replace the caliper carrier.
After cleaning up the threads I turned my attention back to the link. I decided since I can't remove it I would try to use it. The upper link bolt had worked out approximately1/4" to 3/8". The bolt is mounted in rubber, encased in the link. I liberally coated the bolt with silicon and used a two jaw puller to press the bolt back in to it's proper depth. Once the bolt was returned to it's depth it lined up perfectly with the caliper carrier.
With everything lined up I started to install the end cap. I think I know how the bolt got stripped in the first place. The end cap does not set against the flats until fully tightened. What I suspect is that on a prior brake job, the caliper was removed and the brake line was unbolted from the end cap. This opened the end cap and on reassembly, care was not taken to ensure both bolts had a good bite and were tightened evenly. This allowed one bolt to strip and it probably appeared the end cap would hold. Over time the levering action twisted the bolt in the caliper carrier bore enough to back it out of the bore. For the week prior to the separation, I noticed a barely audible noise coming from the rear when stopping in reverse. The sound is hard to describe in words, but sounded like something small shifting in the trunk. The noise was most likely the link bolt working in the bore.
Everything is now back together and working properly. No noise when stopping in reverse. I drove into town and back by the route with the most stops, just to give the suspension a workout. Arriving back home I checked and there was no movement of the link bolt. I think it is going to hold. I still have the new link and will retain it in the parts bin. I also have a call in to the dealer, they are checking availability of the proper MB install/removal tool. I think this is gonna be an expensive tool if it is still available. Will need to have it when I do change the link.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.