how do i find out what brake drum size do i have 9 or 10?

[wiswind]

The FIRST drum that comes up in the Rock Auto website list for 2002 Windstar Brake drums gives an outside diameter.....seems to be the part that Ricebike linked from the Oreilly website.

I recommend that you get a "drum brake hardware kit" that gives you all new springs and clips for the parking brake lever connection to the one brake shoe.
They have one for $3.27 on the Rock Auto site.......

Now....on my 1996 Windstar.....one of my rear wheel cylinders developed a leak.....
Age and the fact that the brake job process with have the pistons inside the cylinder moving outside their normal range makes development of a leak possible.....but not something that is real likely.
Mine developed the leak years after I had done the brake job.
So....I wanted to pass this along IF you end up replacing a wheel cylinder (I just did the rear brakes on my 2003 Sienna and replaced the wheel cylinders as a precaution).
IF you replace a wheel cylinder....I can pretty much guarantee that when you go to loosen the brake line connection the WHOLE brake line will want to twist as it will all be rusted together.
I had this issue on my Windstar AND my Sienna.
My solution....
With the drum off......and the brake shoes removed (if you are doing this all at 1 time.....otherwise...you can leave the brake shoes in place.)
FIRST...slightly loosen the nut on the brake line connection to the back side of the wheel cylinder.....you only need to get it to wiggle a VERY little bit.
THEN Remove the small bolts from the back side that hold the wheel cylinder to the backing plate...
NEXT....push/pull the wheel cylinder through so that you can spin the wheel cylinder on the end of the brake line.....
NOW you can just spin the old wheel cylinder off the brake line and spin the new one on....
YOU may have to twist the brake line slightly to get the wheel cylinder at the correct angle to reseat it onto the backing plate to line the bots back up.....if the nut on the end of the brake line has not come free.

Another thing.....which DIFFERS from what I show in my pictures.....
Before I put the hold down springs in place (the small springs that hold the shoes to the backing plate).
I found that putting the big return spring on as I put the BOTTOM of shoes into the BOTTOM clips on the backing plate....then pulling the shoes apart as I line the TOP of the shoes into the grooves in the wheel cylinder......stretching the bottom spring in the process.......
is MUCH easier vs securing the shoes to the backing plate as I show in my pictures and then trying to stretch that bottom "return" spring into the holes in the shoe plates......
Yes...the shoes will want to flop some as you compress and line up the slots on the retaining spring cups.....but you will get it.
There is a tool to help with the lining up of the retaining spring cup slots with the tabs on the pins.....but it is still a bit awkward for those of us who don't do this often....as the pins want to fall back out of the backing plate.....so 1 hand is busy holding the pin from the back while you compress the spring and line up the slot with the tabs....with the other hand.
https://www.flickr.com/photos/415748...7632198092975/

https://www.flickr.com/photos/415748...7632198092975/

NOTE.....your 2002 may vary slightly from my 1996, but the concept is the same.....

I found that getting new adjusters was not necessary....the adjuster spring is in the hardware kit and my old adjusters were just fine.

The spring tools that I found helpful.....
The bottom tool is for the retaining springs....you can see in from the side to line up the slot with the tabs on the pin.
I got mine at Orielly

https://www.flickr.com/photos/415748...7632197781661/