Canister on brake booster?

[DaBurb]

Could someone tell me the purpose of the canister on the brake booster of my 03 Burb???

Is it a vac pump of some sort?? the wiring harness connected to it (five wires, I think) has me curious the purpose of it..

Thanks

Rick

[farmtruc]

Is it an electrical pump of some sort to keep the vacuum up on the brakes or something, i haven't seen one, but that's the only guess i can come up with.

maybe someone else will know,

[L82gofast]

Can you post a pic? If it has wires going to it, it must be more than a resivour. A pump like Allen said, they probably want a certain amount of vac to bring that burb to a stop and it might just be insurance......

[SSilverado60]

Yeah its a vacuum pump, it will kick on and give you a little more help when you really need it, Im not sure exactly when it turns on but I know thats what it is. My SS has it as well

[Dynatech]

The Burb came with a small power booster, The radius of the power booster is verry important on boosting power (powerapplied versus power provided) there is no room to put a bigger booster so the only way for the booster to to push harder on the master is to apply more vac.