Well the rubber pulling out is a good thing ,if it didnt it would probably have split the radiator.
What year is your 520? If it is a 01 you have the good radiators. The 01s have a 9 core and the 00s only have 8. the 01s also have solid aluminum sides with cross bars welded in , to help with sideimpact.
I replaced the stock rads on my 00 witch aloud me to add the electric fan (STOCK PART FROM KTM) IT is not easy to add the fan to the 00s but can be done. ON the other hand it bolts right on the 01s and plugs right in to the stock wiring harness and the left radiator has the hole foe the thermostat
check the rubbers often they seem to cut easy and need to be replaced
I dont like the gards but I have had to fix or replace 5 radiators (BONEHEAD)
00 380 EXC
00 520 EXC
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