Sprague HP-200 wiper motors

[Iceni John]

I just finished rebuilding my driver-side wiper motor today because it was leaking air internally  -  the passenger-side motor is still OK for now.   After reading Tikvah's thread about his trials and tribulations when he worked on his motors, I was careful to mark the position of the arm's drive shaft and the motor's output shaft.   However, I still forgot to mark the position of the pinion on its hex shaft, but after a false start I got that fixed.   The one thing that threw me for a loop was the orientation of the valve assembly  -  it can be pointing either way, and I put it in the wrong way then couldn't work out why my air connections were pointing the opposite way!   D'oh!   The grease inside had hardened so much I'm surprised it worked at all.   I used a Teflon oil when reassembling it, and a light grease on the gear rack.

The two big O-rings are 3/16" x 1-7/8" x 2-1/4" (labeled as PAR328B7 where I bought them), and the four small O-rings for the valve body are 1/16" x 1/8" x 1/4" (labeled as PAR006B7).   I also used DOT push-on 1/4" air line x 1/8" MPT fittings instead of the original compression fittings, to make it easier in the future to disconnect the motors if they ever need any more attention.

With an inline lubricator for each wiper motor, they now both work smooooothly and quietly.   I love it when I can complete a project for less than $100!   I hope this will inspire others to fix their wiper motors for a few dollars instead of spending $$$$ for electric ones  -  air motors are simple and reliable, and not hard to fix if their O-rings wear out.

John 

[chessie4905]

   Route the exhaust line to outside the body. Not good to inhale the fine oil mist when running wipers.

[Iceni John]

   Route the exhaust line to outside the body. Not good to inhale the fine oil mist when running wipers.

Indeed they are.   I like the smell of Tri-Flow oil, but not that much!   I just finished making a catch can for my airbox drains, so now perhaps I also need one for my wiper motors!

[luvrbus]

Good job John I like air wipers when they are right they work good fwiw I install a 80# regulator then they never change speeds,jerk or slap 

[TomC]

If air wipers are so good, why are virtually all big rigs and buses equipped with electric now? On electric, you can get variable intermittent, lo and high speed, both motors on mine are synchronized electronically. But-good you got them running again-probably won't have anymore problems with them. Good Luck, TomC

[luvrbus]

Electric wipers are so much cheaper is the main 1 reason,you can buy electric wiper motors all day long for 75 bucks I just replace 1 on my MCI