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

[desimunda]

o reilly has two options. 2002 year

[northern piper]

well, the short answer is you pull the drum off and measure. You might also try calling a Ford dealer and with your VIN they may be able to tell you, but I'd still be measuring.

[ricebike]

agree, not that hard to take a tape measure...

also, may have the stamping on the drum for maximum diameter allowed when machined...

usually both inches and in mm readings... if they're not rusted away

[desimunda]

So i can just measure the Outer Diameter of the drum then eh and that should do it. Because i'd rather not take the drum off unless I have to. Will also look for stamping.

thanks

[phil-l]

Drum sizes are generally based on the *internal* diameter of the drum.

[northern piper]

why don't you want to remove the drum? Once the wheel is off it's pretty easy and then you can see the shape of the shoes, test how the wheel cylinder is doing/check for leaks, .. to me that's a no brainer.

As Phil says, the 9 or 10 is based on inside diameter and while the max value is stamped into the casting, I've yet to be able to reliably read that number on the drums I've looked at.

[phil-l]

I understand why he's wary of pulling the drums: It can be a pain to pull old drums if you aren't familiar with releasing tension using the star adjuster - or you've got rusty/worn hardware. That said, they'll have to be pulled do the job anyway. And once you've overcome any challenges required to remove them once, it will go fast and smooth the next time.

[northern piper]

ya, I hear ya on that Phil... tho I must admit that the times I think to myself before doing some mechanical job "oh, I'll only need.." I find out upon starting that I'll also need....

A buddy of mine had a 1996 Jeep laredo. We had to do drums and shoes on his. He called me asking what size drums to buy (he's not a car guy) I ask him to provide the dealer with the vin and then they'll be able to sell him the right drums. Of course he does all this and (go figure) they sell him the 10 inch and he needed the 9.

So, I'm always of the habit now of actually holding onto the piece I need to replace before spending any money...

To the OP, just pull the drum adjuster rubber plug, roll the star wheel to release the shoes and the drums should come off. It might take a bit of work as often there's a rust "ring" that develops, but either way they need to come off.

I wouldn't waste any money or time in turning the drums, it's just not worth it any more with the tight tolerances they put on drums and rotors.

[ricebike]

OK, no need to pull your brakes apart!

i went to the website to see what's up

you'll need part # 665, the brake shoes with rivets on them

the other part # 705 is for the minivans with rear disc brakes that have an internal parking brake shoe setup

so you'll have to verify if you have:

rear drum brakes = 665

or rear disc brakes =701

-------------------------

o wait you need a replacement drum:

that # 9570DGS

has specs for you to measure the outside diameter if you're too afraid to take the drum off initially

http://www.oreillyauto.com/site/c/de...0062&ppt=C0009

Overall Height: 3.01"
Outside Diameter: 11.58"

[thinkbink]

so if i measure the inside diameter of the drum and its 10in its considered 10 inch brakes even tho the actual shoe length is 11.75?

[thinkbink]

im working on an old chevy k1500 and need new drums , they measure 10in. inside diameter but the shoes measure 11.75 long. when ordering the drums they ask for brake size. 10 or 11. so i need 10inch?

[phil-l]

>> so if i measure the inside diameter of the drum and its 10in its considered 10 inch brakes even tho the actual shoe length is 11.75?

Correct. The "size" of a brake drum is based on the *internal diameter* of the drum.

The *length* of the brake shoes isn't directly related to the *diameter* of the drums. Obviously, the curve of the shoe must match up to the inside of the drum - but the length of the shoe reflects how it was designed (i.e., measuring just the length of the shoe doesn't tell you the diameter of the drum).

[12Ounce]

If you are planning to use after market parts, say AutoZone or such; you could just buy both sizes ... complete with both sets of shoes, hardware, etc ..... and later return the parts not used. I often follow this scheme when not sure.

[phil-l]

Also - having done drum brakes a few times:

Take one side apart at a time. It may seem obvious where each spring goes and what direction each part faces - until you have a pile of parts sitting in front of you. Having the other side as reference is very useful.

Also note that many drum brakes have a "leading" shoe and a "trailing" shoe that are slightly different. Carefully inspect your parts - and then do it again - to make sure you're using the correct shoe in each location.

[thinkbink]

thanks, im ordering from roc auto online so dont want to pay return shipping if they are the wrong size. i always thought the drum diameter determined the brake size but wasnt for sure.