The Stovebolt Site Forums The Shop Area Engine Shop Wiper linkage and vacuum motor.

I recently rebuilt my (1951 3100) wiper system with all new rubbers and cleaned out my vaccum motor and lubed it. When i hook the vacuum motor up to the engine with no linkage attached it works fine and takes quite a bit of force to stop it from moving. When i hook it up to the wipers it barely moves them even when reving the engine. Based on how the motor preformed im thinking that some of the new rubber in the wiper linkage is causing extra friction, mainly where the hex on the motor swing arm enters the linkage. Are the hexes supposed to rotate because mine do not and the rubber is a tight fit on it which doesnt make much sense to me. Also are there any other spots that i could lubricte the linkage.

P.s. this is a fair weather car
that i want to keep original as possible. So electric is a last resort.

What/where/how did you lubricate it?

lubrication hole - compliments of Bob Adler, A-D expert extrordinaire

Took it apart myself. Re sealed it with silicon and used white lithium grease. It seemes to have a decent amount of power to it when not attached to the linkage

New Guy - something seems too tight in your linkage reassembly. Also, and others will correct me if I'm wrong but I believe the vacuum may be strongest at idle vs. revving. I also remember a trick where guys were building a vacuum reservoir with an old master brake cylinder setup.

Alex even though I spent many hours over the last several weeks under the dash of my 51 dinking with the wipers, I can't say for sure if the drive arm hexs rotate. But I'm about 89% sure they should.

My experience after much effort to both rehab two vacuum motors and adapt a 6volt VW electric motor...I finally broke down and sent the best of the two vacuum motors to Wiperman (at Wiperman.com) and a week or so later had a rebuilt motor (with a 3 year warranty) that works like a champ. Zero complaints here.

Good Luck
Ron

Reading what you posted, sounds like the linkages may be the problem.

NOTE: I'm not familiar with the wiper system on a 51, so I am using my familiarity of a 59 wiper system.

1. Remove the wiper blades, run the wiper motor under engine power at idle.

2. If the wiper motor runs normal, the wiper blades/arms may be the culprit. Determine which, if not both, is the problem.

3. If the motor barely runs, remove the transmissions.

4. Check that each end where the wiper blade attaches (tower) pivots freely. If good, continue.

5. Check the pivot area inboard of the tower to be sure it pivots freely. If good, continue.

6. Check the end that attaches to the motor by either putting linkage on a rod the same diameter as the motor pin or connect it to the motor and rotate the transmission to make sure it's not binding there.

7. If any place on the linkage is binding, remove whatever is causing the bind or replace the bad transmission.

8. Reinstall linkages one at a time and check motor operation with engine running at idle.

9. When wiper motor works to your satisfaction, reinstall wiper blades one at a time and check operation with engine at idle on a WET windshield.

10. If no issue is found with the wiper blades/arms or transmissions, the issue is inside the motor.

Remember, ALWAYS operate the wipers on a WET windshield.

Check for friction where the wiper arm shaft goes through the cab to see if the shaft is binding in the collar that passes through the cab.

I've had a few like that where the motor worked well, but the shafts were binding as they went through the cab.

Take the wiper off the shaft and see if all moves free.