What is this on my LQ4
 

Attachment 1408965

It is driven off of the serpentine belt.
The engine came out of a large box truck.

Re: What is this on my LQ4
 

charcoal canister maybe???

Re: What is this on my LQ4
 

What year/truck is it out of? I can't tell what its mounted on, is that on the power steering pump?

It looks like a diaphram sorta shape so maybe a charcoal cannister as Clyde said, or possibly a vacuum cannistor. It looks like there is a bunch of wiring going to it tho, instead of like vacuum lines or anything.

HD/Medium duty trucks have had so many cab configurations and special equipment like PTO's that its hard to diagram them or have a reference without knowing what it came out of. Trucks with dump beds or a refrigerated box or something like that have all sorts of weird wiring.

Re: What is this on my LQ4
 

It was a 2005 Isuzu box truck..it is above the power steering pump with its own pulley. It had one big hose that I think went to the valve cover. Everything was cut and removed..so it is hard to tell. It reminds me of the vacuum on the kick panels of ac trucks.

Re: What is this on my LQ4
 

It is a Vacuum Pump, All 6.0L Isuzu NPR had them. Remove it & buy a new belt. You will need a Vacuum "Push-in" fitting for the back of the intake if your running Vacuum assisted brakes.

The Vacuum Pump supplies Vacuum to the brake booster, If the engine dies or the Pump Fails, They also had a back-up Electric Vacuum Pump, Kind of a weird system that is super expensive when parts are needed, IIRC the Vacuum pump alone is over $300 & is only available from Isuzu.

Re: What is this on my LQ4
 

That bracket looks kinda strange as well, you may just want to get a pickup bracket and belt.

Re: What is this on my LQ4
 

Also worth a lot of money to a hotrodder running a huge cam and wanting to retain power brakes.:metal: