Where is windshield wiper fluid resevoir on 1998 C230 Merecedes

could have broken off someof the plastic inside that help moves the wipers. look for small pieces of debris and replace that part

You have a sensor on your washer fluid system. Make sure it hasn't been unpluged. It might not be getting voltage.

1) Fluid resevoir is empty
2) Fluid is frozen
3) Washer fluid hose is disconnected, blocked or kinked
4) Washer switch is faulty
5) Washer pump motor is defective
6) Washer pump fuse is blown

go to a service station with an air compressor and with the air turned down to about 20 lbs blow into the washer top small hole to force fluid thru the hoses,not a lot of pressure so you blow hoses off or rupture something

May be the resevoir bottle may have something stuck in it, you are right, you may have a clogged line. Also check the routing of the hoses to the squirt that they are not pinched or kinked. Any washer fuild leaking anywhere?

Coolant in 50% concentration goes into the coolant overflow bottle. Windshield wiper fluid into the wiper fluid bottle. Power steering fluid into the power steering fluid bottle.
You do not need to add any other fluids to these. Do not add water to the washer fluid bottle for example, if you drive in a climate that would allow it to freeze.

When you pull the lever to activate the windshield washers, do you hear any type of sound coming from under the hood?  A whirring sound should be heard from the little electric pump that feds the washers.
If you can hear the whir, then you should look for a possible clog in the washer hoses (there is more than one...).
If you cannot hear the whirr, then you should check the fuse that protects the windshield washer circuit.  Check your owner's manual for the location and correct amperage for this circuit.
Good luck!

it might be in the motor pump or line is clog can you work the hose

Reservoir —Windshield Wiper

Removal

1. Remove the RH wheel; refer to Section 204-04 .

1. Position RH splash shield aside.
   1. Remove six screws.
   1. Remove three pin-type retainers.
   1. Position RH splash shield aside.

1. NOTE: Windshield washer fluid should be collected in a container after the windshield washer hoses are disconnected.
   Disconnect the electrical connector and washer hoses.

1. Remove the upper reservoir bolt.

1. Remove the windshield washer reservoir.
   • Loosen the two lower reservoir bolts.

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replace line fron resevoir to rear wiper. these vehicles do not filter dirt on wiper fluids. the replace tip on wiper. dealer item only on tip/ nozzle.