2008 Goldwing Trike bleeder screw problem

[Starfall]

I recently bought a 2008 Goldwing with a Motor Trike conversion and started changing all the fluids. Each brake caliper has 4 bleeder screws, but only the top two are used. Most of mine are rusted or completely stuck. Can I use any two to flush the brakes and are replacements only available from Motor Trike?

 

[moolahzoola]

I recently bought a 2008 Goldwing with a Motor Trike conversion and started changing all the fluids. Each brake caliper has 4 bleeder screws, but only the top two are used. Most of mine are rusted or completely stuck. Can I use any two to flush the brakes and are replacements only available from Motor Trike?

You can flush the brakes using just the top 2 bleeders if those are the only ones working . For stuck or rusted bleeders, Motor Trike is likely the best source for replacements, but sometimes regular or aftermarket bleeders might fit

 

[OilStain]

@moolahzoola The reason for the four bleeder screws is that these are often dual piston calipers, and the two top ones are on a separate circuit from the bottom two. The top bleeders are typically for the foot pedal brake, and the bottom ones are sometimes part of the linked braking system.
The trike conversion usually bypasses or modifies this, which is why only the top two are used for the main bleeding procedure.
So yes, you should only use the top two bleeders as per the manufacturer's procedure. Using the bottom ones could cause air to get trapped in the other brake circuit