Wiper Problem m38 1952

joebuck · Post by **joebuck** » Sat Jul 20, 2013 9:59 am

I have a 52 m38 wiper problem. My right wiper does not work. one thing I notice is that there is no vacuum coming from the motor to it like the left side which works fine. Any suggestions? Thanks

Post by **wesk** » Sat Jul 20, 2013 10:26 am

Check your plumbing.

If you have the standard fording plumbing then there are two lines feeding the vac side of each wiper and two going from the fresh air in side to the air cleaner.

If you do not have the fording plumbing then there are only the two lines coming from the left side of the windshield to each wiper's vac port.

If your plumbing is correct then:

Check suction (Vacuum) at the shutoff valve with a vacuum gauge. Should be 10" to 12" between idle and 2500 RPM.

If the suction is correct then:

Check the wiper motor for lube. Spray a little bit of WD40 in the suction side of the motor as you work it back and forth by hand.

joebuck · Post by **joebuck** » Sat Jul 20, 2013 10:43 am

The suction side (right side of right wiper) has no suction coming from hose to air filter. Should it?

Post by **wesk** » Sat Jul 20, 2013 11:24 am

Suction comes from left on both wiper motors. Remember it's the vacuum pump and intake manifold doing the sucking! Left is as you sit in the driver's seat looking forward.

joebuck · Post by **joebuck** » Sun Jul 21, 2013 2:43 pm

The suction side (right side of right wiper) has no suction coming from hose to air filter. Should it?

Post by **wesk** » Sun Jul 21, 2013 10:07 pm

Same question gets the same answer. The suction comes from the left side (driver's side) via the vacuum pump and the intake manifold. Not the right side.

joebuck · Post by **joebuck** » Mon Jul 22, 2013 5:47 pm

The suction side (right side of right wiper) has no suction coming from hose to air filter. Should it?

Post by **wesk** » Mon Jul 22, 2013 9:09 pm

Now look harder at the information I have already presented you with Joe. It makes it quite clear that the wiper motor suction line gets it's suction from the vacuum pump. That leaves the second port (vent port) on the pump that has the hose going to the air cleaner without suction.

This should help you understand. Note both suction and vent ports are on the right side of the motor. References to holding finger over the end of are for the end of the removed hose not the metal ports.

Texbillhs · Post by **Texbillhs** » Mon Jul 29, 2013 7:25 am

I am installing the wiper motors - I understand the no-fording plumbing. What I have a question on is with the fording lines. They follow the right windshield frame arm and go through a grommet in the fender (same as the left), where does it go under the hood?

Second minor question - does the valve bolt to the windshield sheet metal or the roundstock frame? I can't tell from the photos and my windshield is a new one without holes - you have to drill them. The valve I have is the kind with 2 mounting ears for the screws.

evanso1975 · Post by **evanso1975** » Mon Jul 29, 2013 10:36 am

They follow the right windshield frame arm and go through a grommet in the fender (same as the left), where does it go under the hood?

Into the tee on the back of the air cleaner.

does the valve bolt to the windshield sheet metal or the roundstock frame?

Neither. The valve clamps to the 1/4" steel tube. The valve with the "ears" is off the M38A1 (and M151, I think). The original valve looks like this:

Be sure to check out the "M38 Wiper System" album in Wes's photo album; lots of good info there.

This website is helpful too:
http://www.cj3a.info/sibling/m38vent/vent.htm
Don't forget to click on the "Page 2" link at the bottom of that page!

Wiper Problem m38 1952

Wiper Problem m38 1952

Extension of the same issue - where does it go (plumbing)