The Stovebolt Site Forums The Shop Area General Truck Talk Trouble-shoot wiper motor on 58GMC model100

The wipers would only go about 1/4 way up then stop.Is there something i can check?Like the vacum line?Or how/where it is supposed to be hooked up?Found out the other day in a light rain that they "don't"work

is this a vacum problem?I need to know what to check

When the vaccum motor hits the spot where it stops can you hear a leak? How do you get the wiper arm to return from the position it stops? Can you move the wipers all the way thru the path by hand? I'm thinking if the arms are free and the vaccum lines are good, your motor may require a rebuild or at least a good cleaning. Check all the hoses looking for cracks, obstructions and so forth.

Is there a diagram that shows where vacum lines go?

There is only one vacuum line. It's connection on the motor should be obvious.

The paddle inside the motor could be dried out.

I'm sure there is somewhere. I'm not familiar with your set up. Here's something you could try. Find a good vaccum source on your engine and run a line from that to the wiper motor there by by passing you orig. line. You should probabley check your engine vaccum at some point as well. I'm sure someone that is more familiar with your truck will pipe in soon.

Well my truck is ALL original.Looks like the vacum comes off of the exhaust manifold.But that is why I'm asking.There are a couple of places for "hoses"on that there wiper motor.Original wiper motor I bet also....

Humm very interesting. The vaccum should be coming from the Intake. There isn't any vaccum in the exhaust.

I spayed some WD-40 in the breather on top of mine,just to troubleshoot,and that lubricated it just enough to seal up and find the problem.

Jeff

I have repaired a couple of GM vacuum wiper motors and what I found in both was the paddle (which is a hard rubber or hard rubber coated steel, I dont recall for sure) was shrunk/dried up. I took a gamble and soaked the paddle in dot 3 brake fluid and softened it up a bit then cleaned the housing good with brake cleaner. Then lube the softened paddle with white lithium grease (sparingly). Both motors worked great when re assembled. I dont know if this is CORRECT rebuild procedure but poor men have poor ways.

hoses are not hooked up.where do they go on the motor?

Intake manifold

Where do they go on the WIPER motor.sorry I guess i should have stated that---

Can somebody explain where/how the vacum lines hook up to the wiper motor?I am assuming that there are 2 lines .One coming from the engine&other going to the wiper arms?

All the vaccum motors I've looked at (not to say there isn't something different) Have a single line coming in with a hole to atmosphere. Vacuum sucks the air thru the (breather) hole, across the vanes of the motor turning the motor, which in turns the wiper arm linkage. What does yours look like?

There is only one nipple on the wiper motor assembly. Run one vacuum hose from a nipple on the intake manifold to the nipple on the wiper motor. The motor turns the wiper arms by a mechanical connection.

there are these mini lines going to the arms of the wipers.Are those not suppose to be there?

The "Mini lines" are probably the cables that move the wipers. These are not vacuum.

I have a 58 GMC vacuum motor and the arms that accuate the wipers setting on my bench.. I wonder if those "mini hoses" are for the washer nozzles. As others have said there should only be one vacuum line coming from the intake.

You should have one line coming from the intake and connecting to the motor. My motor has two "nipples" on it and it only works with one of them connected. The other doesn't work at all. Turn you engine on, and plug that line onto the nipple, if you have more then one then try either one and see if the wiper arms move. You'll see them move from under the dash.

Those other lines must be for the washer nozzles I assume. My truck doesn't have those. Good luck!

my truck has those mimi hoses BUT i do not have a washer resevoir either.

Got any pictures? Have a friend with a digital camara?