No. CEL is caused by fault codes set at the fuel injection computer or the ignition control computer.

See (copy and paste link in new browser window or tab):

https://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

1. Diagnostic Test Mode 1: Fault Code Retrieval

If the result is anything other than the all is well 1-1-1 red light flash, repeat until no new codes display. Write the CEL codes down and post back here or in a new thread.

Black brake fluid, I guess? Black brake fluid causes corrosion in the brake system including seized brake calipers. Usually replace or rebuild. Quality of calipers can vary by vendor.

Use a Motive or like pressure method to flush the brake lines after completion using DOT four.

Does your 1991 240 have ABS or no?

https://www.brickboard.com/FAQ/700-900/Brakes.htm

https://www.brickboard.com/FAQ/700-900/BrakesABS.htm

700-900 uses different brake calipers, yet the systems are generally the same ABS or no. If not ABS, using a pressure bleeder like that Motive makes may require two-three passes to get air bubble out.

Fluid passes out and air gets sucked in at the caliper bleeder nipple threaded bore. Unless you have an assistant to open (unscrew) the caliper bleeder nipple as you press down on the pedal, and not too far, and close (screw clockwise to snug, not to torque), using the brake pedal is folly. Some that use the brake pedal to bleed brakes may perform a bench bleed of the brake master cylinder with the fluid reservoir assembly off the car. Using a pressure bleeder, I do not have to bench bleed the master cylinder.

Also, if the flexible brake lines show cracks in the outer rubber sheathing, you may want to replace these. ATE is OEM for these flexible brake lines. The unions between metal copper-nikel brake lines and the flexi brake lines tend to corrode together.

Read here on brake fluid flush using the Motive power bleeder. Around 15-20 PSI.

The system is a 1992 240 with ABS.

https://www.brickboard.com/RWD/volvo/1662538/220/240/260/280/new_pads_resurface_rotors_hows_brake_fluid_black.html

Hope that halps.
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