The Stovebolt Site Forums The Shop Area General Truck Talk Vacuum windshield wipers slow down and stop.

Hey guys.

My chevy is almost road ready, but now i noticed the windshieldwipers dont work properly.
First they go up at the right speed. Then they stop, and very slowly they come halfway down before they come to a complete stop.

When I help them a bit with my hands it works great..

Sprayed some lubricant in the vacuumline , but that doesnt work (i guess because it sucks and doesnt blow?)

I've been searching this forum and i wonder if the motor needs a rebuild?

Thats not really an issue for me, but I hoped i would have some driving pleasure this summer..

Any quick fixes?

Thanks in advance!

so you mean

"Vacuum wipers aren't known for Herculean torque, but you can grow fond of the hissing and flip-flop sounds vacuum motors make. Periodically, squirt some motor oil into the wiper-motor air intake (a pinhole near the valve-tripping mechanism, not the rubber hose going to the intake manifold) as the wipers are operating. This will help to seal the moving paddle to optimize power.

"a pinhole near the valve-tripping mechanism"

I've got a hard time understanding what that should look like..? Could you explain it in easier english? sizes? what side?

https://imagizer.imageshack.us/v2/504x672q90/631/nBSwfe.jpg

Where on this picture would it be?

On the other side? or where the air hoze is connected to?

Try them with water on the windshield.

Tried iT with water (rain), works a little better but still "jams". Also sometimes the wipers go up to much, on to the rubber windshield seal. But that's only after I've been jerking them a bit. They are strong going up, but no strength going down. Feels like they need lube in some way

You should look under the dash of your truck and the linkage for your wipers you start jerking on things. You should lube all the pivots first, then with the engine turned off disconnect the vacuum hose and put it into some automatic transmission fluid. Have a helper cycle the wipers back and forth, this will draw some of the fluid into the wiper motor. Then let it sit over night and then connect the vacuum hose and try the wipers. Jerking and tugging on things usually makes things worse.

Take a look at my photo bucket pics I've got some pics on cleaning and relubing the vac motor.

Pete

I know jerking everything doesn't usually help, I just wanted to give it the extra push I thought it needed because they've been standing still in three years. I'll try to lube them in all the ways possible, if that doesn't work I guess I'll have to take it a part..

Well, not to throw water on things, but I have always had vac wipers exactly how you describe in your first post. I have always thought that was normal. This isn't 2014, its 1951. Its why I don't even think about repairing them. I just go with electric ones because no matter how great they work, they wont work as good as electrical ones. [opening umbrella, waiting to get lambasted for my opinion here]

I must agree if you plan to use the truck. Why fuss with it if electrics are available? A different story if it is a meticulous restoration to stock.

Just finished going through this mess on one of my projects. Went and bought the electric wipers. Because, after wasting many efforts trying to fix the vacuum wipers with automatic tranny fluid, checking and re-checking hoses and fitting nothing worked. I started the install of the electrics and in dismantling the vac connection at the manifold discovered a brass fitting was loose, only less than a 1/2 turn with the wrench. So, I thought, what the hay I'll give it a goose to see what happens. Gave the old, a test and like magic, the old boogers worked like a charm. I obviously had neglected to closely check just that one fitting. Sooooo, it was then decision time. Do I stay with the old or go with the new. After a cup of joe and chat with the real boss, decided to go with the new. Works for me, may be different for others. Lesson learned check, recheck and then check again.

Well we'll see. I like the vacuum system, feels so old.. If I'd change to electric, do I only have to change the motor? Or do I need to change the linkage as well?

You change the motor

Arguing the electric vs vacuum bit with some people is as
fruitless as which is the correct engine color or whether you
should vote red or blue or that a Ford or Chevy is the best car
on the market and on and on. For some illogical reason some
people believe that that at one time vacuum wipers were as
reliable as our modern day wipers.
It's pretty rare that Charlie and I agree on anything but I gotta
side with him 100% on this one. If you are building a driver and
expect to use your truck on an everyday basis where you will
encounter bad weather, electric is the ONLY way to go.
There is no arguing the fact that everyone of the modern day
transportation vehicle manufacturers in the world have cast the
vacuum wiper aside decades ago and adopted electric wipers as
standard equipment.
I was a die hard purist, and still am in most cases, but then
again I don't make a habit of driving my truck in bad weather.
I've only been caught in the rain a few times in the last ten
years that I've been driving my stock 1950, 3604. And each time
I've cursed myself for being so bull headed and not giving in
to the electric wipers upgrade.

Some of you guys are probably much more particular about your
Trico vacuum wiper motor "rebuild" than I am, but here's a
series of pictures of the rebuild that I did on one for my truck
several years ago.
A few facts first. New gaskets are not available, new power
pistons are not available, the material in the piston sandwich
is NOT leather, it is a fabric that has been impregnated with
what, I have no idea. I think it might have been a
graphite/rubber compound. When the piston is assembled new, it
was potted in a grease, my guess is, that was to supply the
piston with lubricant for the life of the motor, which was
probably only designed to be several years. Simply coating the
interior of the housing when disassembling your motor with
grease is not adequate and it will soon be wiped dry. The rubber
exhaust valve will be dried out and it is part of the piston
assembly.
So...flip thru the pictures to see what your in for and good
luck:
http://www.pbase.com/dennygraham/spare_tyco_vacuum_motor&page=all

The result of this effort was, that the motor would lift you off
the ground when hooked up to a vacuum pump that is used for
pumping down a HVAC system or Bell Jar. Installed in the truck
with its freshly rebuilt 216, producing maximum vacuum with new
'vacuum' hose and properly sealed fittings, it is a leak free
system that will hold vacuum. All of the linkage was removed,
cleaned, inspected for wear, lubricated and reinstaled with no
binding, in other words the linkage works freely before being
hooked up to the motor. The wipers struggle in anything other
than maximum vacuum and stall when ever throttle is applied.

Not looking to argue guys, just the experience I've had with
Trico vacuum wipers, which is just the same as the experience
that I had with them back in the day when I started driving in
the 50's.

Denny Graham

I need to ask has anyone had a bit better vacuum wiper response when they have installed the dual action fuel /vacuum assist pump?

My vacuum wipers acted similarly when I 1st started using them.
I took the vacuum motor out and squirted about 2 tablespoons of 10w30 engine oil into the port where the vacuum line connected then shook the vacuum motor at every conceivable angle to make sure that oil covered every square inch inside that motor. I then remounted it and it works pretty good for vacuum wipers that is

Keep in mind that anytime you accelerate engine vacuum drops hense your wipers will slow to the point of just stopping in mid wipe. Let up on the gas and they'll go to town again

Driving a vehicle w/vacuum wipers in the rain is a science all to itself
Good luck
Dave

If you are restoring a trailer queen than vacuum wipers. Otherwise if you are sharing the roads with me and my family please consider safety first. Electric wipers, power disc brakes (oh boy now I've opened the can of worms up), radial tires, seat belts, and maybe even power steering.

Everything has a time and place...........

Denny hits the nail dead center. Vacuum wipers by design are marginal at best. The ad on vacuum pump / fuel pump will aid some but its not the magic cure to have wipers that are as good as electric. If your going to run vacuum wipers get some Rain-X.

Denny, thank-you for the detailed pics of your vacuum motor rebuild. This has me somewhat deterred from doing the same: it looks like a terrible pain in the butt.

For another two cents worth ** My dad gave me a new 53 custom cab the day I turned 16 in 1953, as I remember the wipers would just about come to a complete stop with higher throttle demands. I thought nothing of it in those day's. Boy How I wish I Had That 53 Today, If For No Other Reason But To Remember My Dad.

My 1 cent worth. I too, am old enough to remember when the vacuum wipers were on new cars and trucks. Even then, wipers stopped working uphill, worked downhill.
As mentioned above, if you want the nostalgic system, your gonna have to expect that.
Or if you want good, safe wipers, change to electric. I recently did this on my 57. Got it from www.truckandcarshop.com in Orange, Ca. Cost was $180 for the kit. Perfect fit to replace the vacuum motor and comes with a 2 speed switch that looks like the original. It uses your existing linkage.
Now I have great, dependable wipers.

I see all of you like the electric wipermotor over the vacuum.

But i want to make something clear:
Im not going to use the truck as a daily driver. I'll only use it in the summer time on daytrips, and ofcourse that means that it might start to rain. And ofcourse i want to be able to rely on the wipers, as long as they go up and down im glad. I'll just adjust my speed to how much i can see.

It's always been good enough the way it is, and i really like the way they function with this system.

I tried to lubricate the wipers with the motor still installed in the car, but that didnt do the trick. So i'll get it out and take it all apart and see if i can make it work. If that doesnt work i'll have to make the though decision if i should buy a new vacuum motor or a new electric.

Im sorry im so stubborn liking the vacuum system!

I'll try what happens when i put as much time and effort in mine

Go for it Raoul! I'v got the old vacuum system in my 53 truck and in the 41 sedan. Both systems are unrestored. I did the tranny fluid fix in the truck when I started driving it and it helped a bit. The wipers are good enough for me in most situations. They only stop when going uphill, which in Sweden is not very often. Sweden must be a little like Texas in that regard. When I stand on the gas the wipers in both vehicles stop, sure enough. But if I just let off the gas for a second they clear the windshield in no time. In the heaviest rain I sure do slow down, sometimes even stop and wait.
If you are pleased with the vacuum system use it. In the worst case you can change it some other time.
Karl

Raoul,

I have vacuum wipers on my trucks. They work as well now as they worked in the good old days. My trucks are not daily drivers.

I had to be careful a few years ago in pouring rain at a truck show in Macungie, PA. Just as careful as I was in the late sixties and early seventies, when I regularly drove my Suburban in the rain, sleet, and snow.

I have more trouble with fogged up windshields on the inside during heavy rains. Do they make wipers for the inside?

that's called a squeegee Carl, always keep one by your side in that sorta weather

Bill

Or an old towel!

My first truck was a 1950 half ton I bought for 150 dollars in 1971. After two trips to work in the winter I cobbled a 6 volt VW wiper motor into place and put up with wipers that worked but were so wrong. They went Right to left like modern cars. However, I got to work. Was not my finest hour but Dad said his were crummy when the truck was new. His was a 1950 half ton as well. Now I have wipers that work, and go like they are supposed to. It was the first new part I bought for the truck I have now. And it was one of the most expensive parts I needed. But if I were to do another one...OK when I do the next one. It will have electric wipers as well. Fixing vacuum wipers? Like wiping rain off my bald head. Wait for the rain to stop first, then no need to wipe or fix.

I always liked how the Vacuum Wipers would stall on heavy Throttle demand.

I would just back off on the Throttle for a split-second, let it take-a-wipe, then back on the Throttle again.

The Wiper Motors on my 1946 One ton had a little speed control Knob which was nice...so you could run them slow if in slow Traffic, or, open it up all the way if the rain was really havy...or if heading up hill or whatever. ( They would still stall though of course under heavy Throttle ).

Fine with me!

I never liked electric wipers...they have no 'Soul'.



Something I have wondered about now and then, but never tried, is whether the Vacuum Wiper Motors would run just as well on Compresed Air? Like say, 12 or 14 PSI or so.

Anyone know?

So that means A/C is now a safety Item? Thanks Carl!

Maybe someone will post an experience with using a vacuum "storage" canister with the vacuum wipers.

There is a vacuum canister used on larger trucks that have 2-speed-rear vacuum-actuated shifters. That canister is about one gallon in capacity.

My Diamond T, which is a mid size model 509 (14,700 GVW) came with an under dash vacuum reservoir. It is aproximately 1 gal capacity. It seems to give you about 10 seconds of vacuum reserve, with the wipers running.

There is no doubt that electric wipers are best, based on the fact that all modern cars use them. I, however, like the "charm" of the vacuum wipers. None of my trucks are daily drivers but all have been driven in the rain and I am old enough to remember riding in a car with vacuum wipers, when that is all we had.

In addition to the vacuum reserve canister, there is the Trico Electro Vac. One of these came with my COE and it works great. When switched on it comes on only when it detects loss of manifold vacuum. It is capable of pulling 14 inches of Hg vacuum, which is enough to run the wipers just fine all by itself. Yes, I get the irony of using an electric motor to boost vacuum so that your vacuum motor works.

My '42 came with electric wipers (previous owner had already converted to 12 volts). The truck has dual wipers that are independent, without linkage. Thus, the wipers never were synchronized or parked correctly (they were wired through the same switch). Just for the fun of it, I removed the electric wipers, found wiper cores on Ebay, and had them rebuilt by the Wiperman. I found the original vacuum line in the A pillar. They work great and look fantastic when parked. So, I may be one of the few that went the other direction and re-installed vacuum motors. As mentioned above, they have a speed valve, so I like them better than the electric ones.

Kent

I ma glad I'm not the only one who prefers the vacuum system!

So today I took the motor out, took it all apart, cleaned it up, everything looks really good quality wise. No worn out parts, just old dry grease. So refreshed that, now she wipes like never before! (Well that's not true)

Goes up and down like it's supposed to, even in dry windows. With wet windows you can see its much less of an effort to make them move so it works!!

Carl,Rain-X also make an Anti-Fog treatment for inside of the glass,I can't say if it works though but based on their external treatment it might be worth a try.

Also try opening the cowl just a touch and a vent glass or two to purge the humid air a bit quicker.

They are supposed to be "the cab that breathes" after all.

Not to hijack, (OK it is a hijack ), but does anyone know if theres an aftermarket source for those window vents that'll fit our AD's pre-side vent windows?
They have them for the AD's with the side vents..

To get back on track, if I know it's going to rain the 49 stays in the dry but when I get caught out in it I find that with some creative operating techniques the vacuum wipers do a serviceable job of getting me safely to my destination.
I guess it's one of the main things that I like about cruising my 49, theres hardly any automatic anything with it, I actually have to manually start it & manually operate it.....
Dave

When I used to dismantle and clean old Vacuum Wiper Motors, if memory serve, I lubed the insides with Vasaline.

Its a 50, no venti-pane windows. When I crack the center cowl vent, the cab fills with water. I will try the Rain-X on the inside and on the outside and see what happens.
Carl

I'd like to quote myself.

If anyone wants to make the vacuum wipers go faster than the truck itself, this is what I did:

Took it apart.
cleaned the inside from old hard grease.
Looked if the gaskets where in good shape. (if not, replace them, cut some new)
Greased it with a mix of universal grease and thin lubricating oil.

Now they're wiping so well, i wouldnt even consider changing to electric!