Brake Drum Question

[panthermike]

I'm thinking about replacing the drums/shoes on our 2000 Corolla.

I checked out Rockauto and they list the 7-7/8 X 1-3/16, as well as the 9.26" diameter drum. Anyone know if there's a difference or if there's an easy way to find out which the car has?

Thanks.

 

[oilboy123]

Used to be a lot on older cars they had optional sized brakes. If you have two options you have to measure the drums or buy both sizes and use the one that is correct.

Maybe your factory build sheet would tell you.

 

[labman]

That is a huge difference. If the drums show through the wheel like many do, any kind of a rough measurement will do. Even the backing plate on the 7 7/8'' is likely to be less than 9.25''.

 

[panthermike]

Thanks for the reply's. I'll see what I can do.

 

[panthermike]

I just went out and tried to measure the best that I could. I'm not sure if I'm supposed to measure the back or front side.

I measured the front(outer) side, it was around 9", not measuring right against it, about an inch away. So, it seems safe to say that I need the 9.26" drum?

 

[1kickbuttranger]

Any markings on the drum itself that show the maximum ID on them???

 

[mechtech2]

When you get your new drums, clean them off inside and out with brake cleaner, and spray paint the outside with Rustoleum. Use a number of light coats. I have almost 6 years on my drums, and they look brand new.

 

[eljefino]

Do you have the big or small motor?

Sometimes your old drums will have "max dia xxx" stamped into them, will be on the outside but hard to find/read thru the dust.

 

[panthermike]

Originally Posted By: eljefino
Do you have the big or small motor?

Sometimes your old drums will have "max dia xxx" stamped into them, will be on the outside but hard to find/read thru the dust.


I think the car only came with a 1ZZFE engine. I will definately take a look at the drum, check for anything I can.

Thanks.

 

[JakeR22]

How many miles are on the car? Are you sure then even need to be replaced?

 

[panthermike]

Originally Posted By: JakeR22
How many miles are on the car? Are you sure then even need to be replaced?


The car has 152K miles. The reason I'm thinking of replacing the drums is because of an issue we've been having with the brakes.

1. There is a slight squeal from the brakes, not a big deal. Occasionally sounds slightly worse than a squeal.

2. The car "pulls back" when brakes are applied. It's hard to describe, kind of "stutters." The car doesn't stop smoothly. It feels like your putting on more pressure to the pedal and then less, repeatedly. Not sure if this makes sense

Anyways, I've had the brakes checked twice. The front rotors are smooth and only have 40K miles on them. The front pads are at 50-60%. The brakes aren't hard or soft, so I don't think it's the master cylinder or the booster. We had the rear shoes replaced about 50K ago. The only thing that's original are the drums, w/ 152K miles.

I'm glad you asked that question, what do you think?

 

[labman]

Pull them off and have them turned. Also measure them. If the problem quickly returns, you will know what size to buy.

 

[ikeepmychevytoo]

Originally Posted By: panthermike
The car "pulls back" when brakes are applied. It's hard to describe, kind of "stutters." The car doesn't stop smoothly. It feels like your putting on more pressure to the pedal and then less, repeatedly. Not sure if this makes sense

Why not inspecting them. For "out of roundness" take radial measurement from at least four different points inside. And it is highly probable that max. inside diameter (scrap diameter) is already be stamped outside at convenience.

Sometimes front caliper slides stuck. Some cars recommends cleaning/lubrication or changing the sliding pins with each brake pad change. Stuck caliper pins may not stand against the brake application but can prevent the piston from fully retracting back. Problem is the master cylinder fully retracts, and compansates the lost stroke by taking a little more fluid from reservoir. Now, for the next application there is a reduced cylinder volume (stroke) for the front cylinders, so reaches max pressure much sooner, and the sytem proportionally applies the rears earlier than designed and firmer thinking front should still have displacements to complete. Depennig on speed and power at the pedal, brakes may feel biased to front or rear. Gradual slowing down might be harder.

 

[cousincletus]

Could be a stuck rear wheel cylinder too. I agree w/getting the drums turned first.

 

[panthermike]

Originally Posted By: cousincletus
Could be a stuck rear wheel cylinder too. I agree w/getting the drums turned first.


I didn't even think of that, I'll look into it.

 

[panthermike]

Well, I went and had the drums machined.

It smoothed it out quite a bit, still some but not too bad.

It feels good enough for a while. Maybe around 200K, I'll swap them out.