Trico Windshield Wiper Motor Doesn't Oscillate

S

some mech 3

Member
When I engage the switch the motor shaft moves one half cycle counter clockwise and stops. When I disengage the switch the shaft returns to its stop. The paddle has been rebuilt, there are all new gaskets, the yoke, valve kicker, and slide valve all work properly when turned by hand. The wiper body is in excellent shape. And it has been well lubricated. Any ideas? Thank you in advance.
some mech 3
 
Mine does the same after a $150 rebuild. Look forward to an answer. Could be the blade is too tight against the window? Window is not wet? Inside of wiper mechanism not properly lubricated?
 
It may depend on the wiper, early with the screw-on front cover or the later version with the snap-on cover. I had a similar problem with an early (original) vacuum wiper. Sent it to John Holland in Ohio to be rebuilt and was informed that this is a common problem with the early ones due to pitting and/or warping of the pot metal housing. The later version for the most part corrected the problem. I was advised to just toss the early wiper and replace it with a later version. I did so, saved money, and the later wiper works properly. Take my comments for whatever they are worth.
 
Need more info. What kind of car is it in? Tudor? Fordor? Roadster? ETC. Did you try it before mounting in the car? As Superhart stated, is it the original motor with the two small screws holding on the front cover or the later one with the snap-on cover? There are many small passageways inside these units that can get clogged. Much like a carburetor, merely replacing the paddle and other parts won't help if any of these passages are clogged. The on/off assemblies are also more complicated than we think and must seal 100% to function properly.
 
With the TRICO wipers, and particularly the first generation ones original to the model A, everything needs to be top notch for the wiper to work. Hence, leaking passageways could be a contributing factor.

However, when you say that the wiper motion starts but stops half way, you almost certainly have a problem with a warped bowl, which is very slightly wider at the center of the motion, such that the paddle will not seal properly.

This should be checked before fitting the cover by moving the paddle over its full motion in the bowl and with a strong electrical light at the back of the paddle. Any light coming through means a bowl where the paddle doesn't seat right.

It is difficult to see, but look carefully at the attached photo where there is a small stream of light coming through. It isn't much, but it is enough to ruin the performance of the wiper. This wiper displayed exactly the same problem as described by the original poster.

If you insist of using the original TR-series wiper, find the best bowl you can get. You may still need to custom make a paddle and seal to fit the bowl. Be prepared to have to re-restore the wiper after some time of operation. (when the bowl has warped further).

Obviously the valves and passageways also have to be free and not leaking. I have had some success with laying out with a toothpic very fine lines of permatex sealer on the lid gaskets were the walls of the channels in the lid are supposed to seal
 

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The Trico motor is a later style with the oval cap back. It was on my 1931 coupe when I bought the coupe in 1963. I tested the wiper motor by holding the motor in my hand and connecting the car's vacuum hose to it. I cleaned the many orifices by forcing compressed through them. I will try your many suggestions. Thanks.
some mech 3.
 
some mech 3 said:
When I engage the switch the motor shaft moves one half cycle counter clockwise and stops. When I disengage the switch the shaft returns to its stop. The paddle has been rebuilt, there are all new gaskets, the yoke, valve kicker, and slide valve all work properly when turned by hand. The wiper body is in excellent shape. And it has been well lubricated. Any ideas? Thank you in advance.
some mech 3
Click to expand...
Remove line to wiper squirt a few drops 3 in 1 oil in wiper! Reconnect and try!!
 
This is what I did...may work for you.
I took the vacuum line off and squirted some hydraulic oil into the wiper motor. I exercised the motor with the wiper arm attached, carefully, going back and forth. The motor loosened up. I re-attached the vacuum line and it has worked ever since. For me it was a simple fix and I hope the same for you.
 
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