Brains Trust Help - Vacuum Wipers

[Haridimos]

Originally Posted by local chap

Some time ago, i got a pair of m151 mutt vacuum wipers off e-bay, brand new in boxes. They fitted up fine to the blitz windscreen, but i also had to buy MUTT wiper arms...

Do you have a photo of the M151 wiper fitted on your Blitz windscreen?

..and does this work properly?

[Bob Phillips]

Just a question for those with 216 engines(Phil ??) Many years ago I co-owned a 3 ton Chev wrecker with a 216 engine. It had slow wipers and the vacuum assist brakes. I seem to recall that we were able to install a vacuum reservoir with a one way valve that would hold some additional capacity of vacuum which helped both the wipers and the brakes. Anybody tried this??

[Phil Waterman]

Hi Bob

Yes vacuum accumulators or reserve tanks work to a some extent, but it really depends on how much of the throttle you have to use to drive the truck. With my HUP the vacuum wipers work pretty well when I lift my foot or go to down shift, and because most of the time you drive that truck at about half throttle the wipers work. On my big C60S with the radio box when it had its original 216 engine the normal driving throttle was all the way on the floor or off the peddle completely you can guess the results no wipers or wipers.

I tried an accumulator can about 4 gallons, with a one way valve in line to the wipers the problem is how quickly you can store the vacuum and how quickly you us it. Connect the tank with the normal 1/4 inch line it really didn't work well. Connect the tank to the manifold through the 1/2 power brake port and the tank would work OK but not great.

I had the 4 gallon mounted on the C60S for a number of years for another purpose, I ran a small line 1/8 to the bottom of the clutch housing to scavenge the oil that leaked from the rear main. You could here this little hiss or slurping sound after you parked the truck which would last for several moments.

The best thing I've found is RainX with the reverse slope windshield it works better than the wipers do.

Cheers Phil

PS Changing to a 261 engine also works plenty vacuum.



Related Thread http://www.mapleleafup.net/forums/showthread.php?t=6896

[Jordan Baker]

Thanks for the info on the lenght needed.

[Phil Waterman]

Hi Bob

You asked about slow moving wipers with a 216 engine, I knew I had some video that showed driving in the rain. So I've added some drivers eye view of my HUP and C60S on the road. Look at the bottom of the page here is the link http://www.canadianmilitarypattern.com/CMP%20Videos.htm

There are a Hi Resolution and Medium Resolution of each video.

You can also see that the wipers didn't really make much difference with the Rainx on the glass

Cheers Phil

[Phil Waterman]

Hi Scott

Vacuum wipers when they are brand new and well lubricated etc are faster. But any kind of vacuum leak particularly in the tube going to the wiper or at wiper motors really slow them down.

Connect a vacuum gauge to wiper line if running down the road and you have 7-10 inches of vacuum then the wiper should work OK. My C60S Beauty has good new vacuum motors and with the new 261 engine that doesn't need to be run hard it pulls 10-15 inches at road speed an 25 inches when you lift your foot the wiper motors really do work well.

But what you see on BEAST is my typical experience with wiper motors. They are good enough to pass safety inspection but I really rely on the Rainx for keeping visibility.

Cheers

[Jordan Baker]

Over on the G503 forum one of the memebers posted a very good rebuild series on the Trico wiper motors. Figured it may help someone on this forum.

http://www.g503.com/forums/viewtopic.php?f=4&t=192841

[Bob Carriere]

Hi Scott

...."They can also supply new fuel pump for the 216 motor that has a vacuum pump fitted to the bottom to stop the problem of slow windscreen wipers...."

That 2 stage vacuum/fuel pump was very popular in the 50s .....BUT..... will not fit within the tight space of the CMP cab 11 or 12 or 13....... in fact I will sell you one cheap if you wish to try it.... in fact even the original with the glass bowl is a tight fit... very little room to spare inside a CMP engine bay.

Bob C.