Where is power steering resevoir 2002 trailblazer problem we had a mechanic tell us this vehicle has a closed system on the power steering so he could not check the fluid level. I have never heard of that on a power steering system and now we are having problems with the steering. I need to know how to check the power steering fluid level.

This vehicle could have come with two different types of power steering ! One electric an the other hydraulic needing power steering fluid .
If your vehicle has no power steering fluid reservoir it has electric power steering .
Power Steering System Description and Operation (Electronic Power Steering)
Power Steering System Description and Operation (Hydraulic Power Steering)
An they did have a recall for the electric power steering !

Electric Power Steering

https://www.usatoday.com/story/money/cars/2014/03/31/gm-recall-steering/7127117

Firstly, I've never heard of a power steering system with a filter in it. I see no reason for said filter. And you never have to flush a power steering system. Any time I add fluid, I never use power steering fluid in a bottle that's labeled to be for that. It's much more expensive than transmission fluid, which is the same fluid. Unless of course these newer vehicles have added some things that really are not needed. Like a power steering fluid filter!!!! There's no such thing. Somebody correct me if I'm wrong, but you're going to have to prove it to me.

ask a local mechanic to have a look as it could just be the power steering belt has come off or if its the electric motor type power steering pump then it could be a fuse or a loose connection ,sorry to be vague here but never seen this american built vehicle here in spain

Hard to guess the cost until we know the component that has failed. It could be; power steering pump, resevoir, hoses, presure switch, or steering rack. Some one will have to climb under there and see which one it is.

The most exspensive one is the steering rack which would cost about 1000.00 - 1200.00 to replace and it requires the vehicle get an alignment when the job is finished.

Belt loose, tensioner bad, rack and pionion piston leaking internally, air in the system.

Have you checked your tie rods? Possibility one is either bent or broken, I've seen it before on TB's. That pulley shaft is a common problem to break, especially when cold out. PS pumps/pulley shafts and tie rods will snap if doing donuts in the snow with the steering wheel cranked, or off-roading. The PS is completely mechanical, no fuses or relays.

power steering should be on the left side with a strange green cap that u have to take off with a screwdriver or pair of pliers

As you brakes wear down your fluid level goes down with them. The pulsing is probably tires.

Hello there, here is a picture to better assit you in finding your PS resevoir. It is directly above the oil filter which is blue in this picture. The cap is black has orange letters. http://www.fastfieros.com/enginesavailable/images/3800sc_seriesIII_06.jpg