Vacuum pump test

1959 - 1978, M151, M151A1, M151A2, Technical questions and discussions, regarding anything related to the M151.
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Mike1956
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Vacuum pump test

Post by Mike1956 » Sun Apr 15, 2018 5:24 am

How much vacuum should a new pump have? I have new pump and wiper motors and wiper are very slow. Thanks It is a1960 m151

Rickf
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Re: Vacuum pump test

Post by Rickf » Sun Apr 15, 2018 6:32 am

Very first thing to try is to take the return vacuum line off of the tube going under the dash and just let it hang and try the wipers now. If they work good then either the tube going under the dash is clogged or one of the tubes going to the air cleaner is clogged. I personally leave that line just barely attached to the tube so that if I do need the wipers I just pull it off. The other thing that can be an issue is the other tube under the dash leading to the wipers. These U tubes gather moisture due to there design and they rust inside the tube and clog up. If you have good flow and vacuum on the line coming out of the pump then the wipers should work fine. Be sure the lines are hooked up to the wiper motors correctly, be aware that the right and left motors are opposite connected. Last but not least do you have the intake manifold line from the back of the intake running into the inlet of the vacuum pump? Are you sure it is on the right connection?
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Mike1956
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Re: Vacuum pump test

Post by Mike1956 » Sun Apr 15, 2018 6:42 am

There is no vavume line from intake to pump. When I bought mutt that is how i got it. Is there a diagram to view so I get it right? Thank you
Mike

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Re: Vacuum pump test

Post by Mike1956 » Sun Apr 15, 2018 7:06 am

There is no vavume line from intake to pump. When I bought mutt that is how i got it. Is there a diagram to view so I get it right? Thank you
Mike

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Re: Vacuum pump test

Post by hambone » Sun Apr 15, 2018 8:30 am

This is an old drawing I dug up, I know it's bad but....
Switch side goes to the vacuum pump, other side is just vent, as Rick said, make sure your connectors or lines are not clogged.
These wipers turn slow, nothing like electric wipers, using Rain X on the windshield will help a little.
Image


Mike1956
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Re: Vacuum pump test

Post by Mike1956 » Sun Apr 15, 2018 9:37 am

Thank you. That is the info i've gotton so far.
Mike

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muttguru
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Re: Vacuum pump test

Post by muttguru » Sun Apr 15, 2018 9:49 am

Just a reminder, guys. If Mike's M151 is a 1960 version, both the wiper motors will be "curved shape upwards", not as in the diagram Hambone provided. The one-up, one-down setup came in during 1962.

If the vacuum pump and lines are in good order but the wiper motors still run slow, the leather seals inside the motor could be dried up. Somewhere I've got the instructions for dismantling and servicing the vacuum wiper motors.
Ken
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Re: Vacuum pump test

Post by hambone » Sun Apr 15, 2018 10:05 am

muttguru wrote:
Sun Apr 15, 2018 9:49 am
Just a reminder, guys. If Mike's M151 is a 1960 version, both the wiper motors will be "curved shape upwards", not as in the diagram Hambone provided. The one-up, one-down setup came in during 1962.

If the vacuum pump and lines are in good order but the wiper motors still run slow, the leather seals inside the motor could be dried up. Somewhere I've got the instructions for dismantling and servicing the vacuum wiper motors.
Ken
Ken, you guys amaze me, I learn something everyday, :D , my windshield must be at least a 62, it does have the metal hood rests.

Rickf
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Re: Vacuum pump test

Post by Rickf » Sun Apr 15, 2018 3:58 pm

I was not aware of the motor difference either. Did the lines snake around to the other side of the motor or was it a different motor altogether? if that is the case the odds of it have the original motor are slim.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Re: Vacuum pump test

Post by W. Winget » Sun Apr 15, 2018 4:54 pm

Couple of squirts of 3 in 1 oil (hardware store) will really help to restore the seal, especially leather, but it's almost nothing to replace the leather vane inside of one if you do disassemble it, rubber vanes may require a replacement kit.
V/R W Winget
Looking for 1918 Standard B 'Liberty' truck parts

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