Can I pick up vacuum from air filter for wipers?

1950 - 1952, M38, questions, discussions, regarding anything related to the M38.
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Re: Can I pick up vacuum from air filter for wipers?

Post by JMZ421 » Wed Oct 10, 2018 2:55 pm

This is a picture of the lines on my M38. John
IMG_1304.JPG
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Re: Can I pick up vacuum from air filter for wipers?

Post by Radtech » Wed Oct 10, 2018 3:04 pm

On the M38 a line comes off the manifold to the vacuum pump fitting closest to the block while another line comes out of the vacuum pump and goes up to the wipers to provide a steady vacuum for the wipers while the engine is at idle.

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Re: Can I pick up vacuum from air filter for wipers?

Post by signsup » Wed Oct 10, 2018 4:28 pm

OK, here's what we did. We installed a T fitting right at the fitting coming out of the top of the manifold right behind the carb. Foor some reason, we weren't getting vacuum out of the booster or pump or whatever. We vacuum at our new T and the engine runs fine. We have good wiper function on the drivers motor, but the passenger motor only pushes in one direction and then we have to drag it back by hand. It looks to us that we do not have the correct motor installed on the passenger side and we may need to tweek the plumbing, go through the motor as it has some sort of push/pull switch on the left side of it, or we may need a new/correct wiper motor on that side.
We are 100 ercent better off than we were yesterday and knocking on the door of having a fully functional system.

We will plumb the return line to a fitting on the back of the air cleaner after we get this passenger motor sorted out.

Here's what we got . . .
jc wiper p.jpg
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Re: Can I pick up vacuum from air filter for wipers?

Post by JMZ421 » Wed Oct 10, 2018 5:30 pm

I would try to find the original fuel pump and plumb the wipers back to factory like they are supposed to be. Just my opinion. John

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Re: Can I pick up vacuum from air filter for wipers?

Post by Scoutpilot » Wed Oct 10, 2018 5:30 pm

Why is the rubber line kinked? It should be as close to straight as possible. Worst case, it should go around a wide looping circle. Other motor only goes half-way? It may need a rebuild. But if what I see is what I suspect, you should only have one steel line to the first rubber, to the first motor and if the other motor is vacuum, its vacuum source should be coming from the first motor. Your photo needs to be of the wider picture.
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Re: Can I pick up vacuum from air filter for wipers?

Post by signsup » Wed Oct 10, 2018 5:59 pm

OK, we'll take some wider views in the morning. Here is the working drivers motor, which appears to be an MB motor. Sorry, same close up view. We were more interested in the motor ID than the routing. But, if we don't get blown away tonight, we'll revisit the jeep in the morning.
jc wiper motor d.jpg
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Re: Can I pick up vacuum from air filter for wipers?

Post by signsup » Wed Oct 10, 2018 6:04 pm

Looks like I could replace both motors with NOS style for $100. And sell my working MB style and a almost working motor for that and have two NOS, working motors.

https://www.ebay.com/itm/G740-G758-G838 ... :rk:4:pf:0
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Re: Can I pick up vacuum from air filter for wipers?

Post by signsup » Thu Oct 11, 2018 10:17 am

OK, here's a little overall image . . .

Maybe we have something not connected properly. The motor on the passenger side just seems incorrect to me as it only has one inlet for vacuum, no outlet for venting. and, the small knob on the left of the motor gets pressed in but does not stay, so I'm thinking something is up with this passenger side motor.
jc wiper hose.jpg
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Re: Can I pick up vacuum from air filter for wipers?

Post by mdainsd » Fri Oct 12, 2018 6:58 am

The passenger side motor looks like the type used on an M37 Dodge truck. Those trucks have the push/pull on off switch right there on the motor. M38s use a needle valve over by the drivers side of the windshield frame to control the wipers.

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Re: Can I pick up vacuum from air filter for wipers?

Post by Ken Perkins » Fri Oct 12, 2018 7:56 am

That ebay wiper motor is for a M151 and not M38
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Re: Can I pick up vacuum from air filter for wipers?

Post by JMZ421 » Fri Oct 12, 2018 10:01 am

Here is my M38 setup, John
IMG_1307.JPG
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Re: Can I pick up vacuum from air filter for wipers?

Post by Ben Dover » Fri Oct 12, 2018 12:14 pm

Those familiar with the M-38 ORD 9 SNL G-740 for the M-38 will be familiar with the Windshield Wiper Motors used to replace the Originals. The ORD 500844 (S-583-1) is listed as superseding the original TRICO 63527 (no shut off). The S-583-1 is the MB/GPW, CCKW Open Cab, M-37 type Motor with the push-pull knob. The S-583-1 when mounted on M-38 Windshield swings a slightly different arc.

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Re: Can I pick up vacuum from air filter for wipers?

Post by W. Winget » Fri Oct 12, 2018 12:22 pm

Funny, rifle mount is upside down, just discussed in another topic today.
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Re: Can I pick up vacuum from air filter for wipers?

Post by Ben Dover » Fri Oct 12, 2018 12:35 pm

The Rifle Holder Bracket holes do not have an "Up" or "Down".
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Re: Can I pick up vacuum from air filter for wipers?

Post by W. Winget » Fri Oct 12, 2018 1:13 pm

Your right, now fold down the windshield and grab your rifle from the inside of the jeep....hurry now, your being shot at....
Your right there are no up or down bracket holes.
Look at the position of the one in the photo of WWII mounted on the jeep and tell them they got it wrong too.
I'm positive there are mounting instructions supplied with the mount and those guys in WWII didn't follow the pub.... :roll:
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