As I recall the '88 ABS was rear only. The flashing light means you've got a stored code with the ABS system. I don't know how to pull it without a Vetronics Tech 1 tool with the proper ABS pin E cable and mass storage cartridge. You could try taking it to a Pepboys et al and see if they can pull or reset the code for you. Or you could disconnect your battery for 20 minutes and see if the code resets itself. It could be that the system detected the leak and set a code that doesn't automatically clear when the problem goes away.