Rear brakes pulsating after replacement

[wiswind]

Along with what 12ounce said.....one of my rear wheel cylinders started leaking (around 200K miles / 12 years). I replaced both sides......new wheel cylinders are not very expensive.
Also, they are easy to replace when you are doing other rear drum brake work.
One thing that I found on both my '96 Windstar and my 2003 Sienna, after all the years......the nut on the end of the metal brake line may not want to turn on the line......so the whole line turns. The EASY solution to this for me on both vehicles (I knew better after that first on on the Windstar) was to remove the 2 small bolts that hold the wheel cylinder to the backing plate....and then put the wrench on the brake line fitting on the rear of the wheel cylinder and turn the WHEEL CYLINDER on the brake line......which avoids twisting the brake line....and the fitting will loosen up on the brake line in the process. If not, you can just spin the new wheel cylinder onto the brake line fitting.....which avoids having to line up the stiff brake line to the wheel cylinder AND line up the threads on the fitting at the same time.
My suggestion is to replace the wheel cylinders on an older vehicle if you have to go in there and disturb it with brake work as that is tempting it to leak. Best to do the job completely and never have to go back in there again.