Different wheel assemblies need different care. The case where too much grease has been injected and covers the break parts has been discussed a number of times in TT forums. I have not experienced it myself.
Old times, required trailer wheel hubs be disassembled, greased and reassembled. Bearing play was adjusted during the process. This did not need to be done very often and sometimes was neglected all together. It was obvious how much grease to apply.
Adding grease zerks and drilling channels for grease flow slowly became the normal. Too much grease became the norm. Various designs developed various problems from too much grease. After all, why have user serviceable grease zerks if they were not meant to be used often.
Blown or pushed out seals or wheel bearing have occurred in some designs. Grease on break drums or disks also occur. Rubber boots have been exploded.
The manufacture is responsible for not contaminating the break drums on new axles, not the buyer. A mechanic hired to service the wheels is responsible when he works on them. The owner is responsible when he does his own service work. The owner usually pays regardless. It is just another expense to owning a TT.
Read the manual for your axles. Follow the instructions. You have learned the hard way. I have never found the instructions to be clear, but it is all I have.
I wish you good luck and happy trails ahead!
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