Vacuum Wipers

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Sep 11, 2015 | 05:17 PM

BaggedMerc

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Vacuum Wipers

Hi Guys,

I have no experience with vacuum wipers.... so maybe this is something small.

I have a 51 Mercury M3 and it has vacuum wipers. Motor is a SBC 305 TPI if it matters.

When I tested the wiper motor with a small piece of hose right off the plenum, it worked. Now withe everything buttoned up, I have a "T" to the MAP sensor and to the wiper motor.

The wiper motor won't work now. Ideas???

Thanks John

Sep 11, 2015 | 05:53 PM

Jolly Roger Joe

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From: Rockingham, VA

Quote:

Originally Posted by BaggedMerc

I don't know much about vacuum wipers either, but it sounds like you lost the vacuum somewhere. Plug the other side of the tee and see if they work.

Sep 11, 2015 | 05:57 PM

JWC 3

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From: Tennessee

Use a dedicated vac line for the wipers and another for the map.

Sep 11, 2015 | 08:07 PM

BaggedMerc

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There is vacuum there if I pull the hose off the motor. Not sure how much should be there though... no gauge.

No sure where else to tap. The plenum has 3 ports and I'm using them for: MAP, brake booster, and Fuel pressure Reg.

Sep 11, 2015 | 08:22 PM

56panelford

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From: northwestern Ontario

Any pictures of this bagged Merc? Please and thank you.

Sep 11, 2015 | 08:31 PM

BaggedMerc

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Just realized there are 2 vac ports. Derp.

Will swap tomorrow and test lol.

Sep 11, 2015 | 08:34 PM

BaggedMerc

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Quote:

Originally Posted by 56panelford

Any pictures of this bagged Merc? Please and thank you.

I have a build thread in here somewhere

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Sep 11, 2015 | 09:30 PM

JWC 3

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From: Tennessee

I like! nice looking truck .

Sep 12, 2015 | 05:27 AM

#10

pbsdaddy

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From: Central Delaware

Try a bit of lube on the vacuum unit and arms. Also, check the hose for cracks or other leaks. Last, spray some water on the windshield before trying the wipers. I've owned a few vehicles with vacs and none of them liked dry windshields.
You might want to consider a vac can.

Sep 12, 2015 | 10:39 AM

#11

AXracer

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Joined: Oct 2004

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From: Durham NC

Vacuum motors on wipers are really simple buggers. Don't be afraid to disassemble it, clean it and relube all (few that there are) moving parts with a good light bodied grease like white lithium. It will usually have it working better than new.