Carbon brushes are the part that decides whether a vacuum motor gets a ten-minute service or a full replacement. This Ametek Lamb carbon brush is listed against Ametek Lamb motor 116309-00, the 5.7 inch single-stage thru-flow motor used in commercial backpack, canister and wet/dry machines. If the armature is still clean and the motor has simply gone weak or intermittent, brushes are the first thing to check and by far the cheapest thing to change.
Built for
- Janitorial and BSC service techs keeping commercial backpack and canister vacuums on the floor instead of on the bench.
- Central vacuum owners doing the periodic brush inspection rather than waiting for the motor to die outright.
- Car wash and shop vacuum operators, where the 116309-00 is a common service motor and machines run all day.
Why brushes fail, and how to read the symptoms
A small blue spark at the brush face is normal on a universal motor. A large spark that wraps around the commutator is not, and neither is a motor that runs intermittently or has lost obvious power. Pull a brush and look at the carbon: new brushes start around 3/4 inch of usable carbon, and the accepted replacement point is 3/16 inch. Above that, the brushes are not your problem. Below it, replace them before the holder starts scoring the armature at operating speed, because that turns a cheap repair into a motor purchase.
There is also a point where brushes are the wrong answer. A burnt smell, a blackened and pitted commutator, or a bearing you can feel wobble by hand all mean the motor itself is finished. Ametek vacuum motors are generally regarded as an 800 to 900 hour part, and past that the armature and bearings tend to go regardless of how much carbon is left.
Fitment
This brush is sold against Ametek Lamb motor 116309-00. Order by the number stamped on the motor label, not by the model number of the vacuum, because the same machine model is often built with more than one motor over its production run. Ametek vacuum motors take two brushes, one per side, and standard shop practice is to replace both at the same time so they wear evenly. Confirm the quantity in your order before you start the job.
Specifications
- Application: Ametek Lamb carbon brush, cross-referenced to motor 116309-00
- Host motor 116309-00: 5.7 inch, single stage, 120 V, thru-flow peripheral discharge
- Replacement wear limit: 3/16 inch of remaining carbon
- Brushes per motor: 2
Ametek does not publish physical dimensions or a rated service life for this brush, so none are quoted here.
Frequently asked questions
Is this one brush or a pair?
Listings for this part number are typically a single brush, and every Ametek vacuum motor uses two. Check the quantity on your order and buy two if you are replacing a set.
How do I know the brushes are actually the problem?
Remove one and measure the carbon. More than 3/16 inch remaining, plus a smooth commutator, means the fault is somewhere else. Less than 3/16 inch, or a large spark wrapping the commutator, means replace both.
Will new brushes fix a motor that smells burnt?
No. A burnt smell, a pitted commutator, or a wobbly bearing means the motor should be replaced. New brushes on a damaged armature will not last.
Can I change them myself?
On a 5.7 inch Ametek the brushes are reached by removing the cooling fan cover or the retaining band, then the two brush hold-down screws. The motor usually does not have to come out of the machine. It is a routine service job, not a rebuild.
How do I make sure it fits my motor?
Read the number printed on the motor label and match it to 116309-00. If your label shows a different number, contact us with it before ordering rather than guessing from the vacuum model.
Discount Cleaning Products stocks Ametek Lamb motors and motor service parts alongside the machines they go into, so you can match a brush, a motor and a filter in one order. Our US-based team can help you read a motor label and confirm the right part before you buy.
