basic ?'s

[chelsea's dad]

just bought a '81 240D, manual, 180k for $2,400. original engine swapped out with another 4 banger with 110k on it. clutch not working and clear fluid leaking from between bell housing and tranny, so am changing slave cylinder tonight. ?: the radiator has green anti freeze in it. is this ok or do i need to use the gold colored stuff recommended for mb's?
the car also has cruise control. didn't try it on the way home. any thing i need to check, be concerned about or common problems?
one of the boots on the axle shaft is starting to crack. help with a link for repairing them? do i need to remove shafts to replace boots or are there replacements that will fit over shaft and then seal up?
lastly: had a '79 240D before and vin started 123123. this one starts AB23. any major changes between 79 and 81?
any and all help greatly appreciated. thank you in advance.

bill