Air wiper motor/switch. Maintenance required

[Full Floater]

I'm new to the air wiper world, or at least; new to servicing them.   Never really had much trouble with them before.

The air wiper switch on this 75 R600 is leaking air in the OFF position.  What is my best way of resolving this?  Is there an o ring or a kit or something that I can replace?

And as for the air motor itself, although it works fine, it's probably never been touched in 48 years, is there anything I should do to it in regards to maintenance?  Cleaning?  oiling?

 

Many thanks!

[doubleclutchinweasel]

I'm not sure, but I THINK Haldex-Midland may still sell those rebuilt switches.

I see several types online.  https://www.heavydutypros.com/mack-wiper-air-control-valve-7623-7547070.aspx?utm_medium=paid&utm_keyword=&utm_source=google&utm_campaign=16494479656&utm_network=x&utm_placement=&utm_source=&utm_prodid=174594&gclid=Cj0KCQjwmICoBhDxARIsABXkXlJsZ_StkSy2jAWbs5qq_sMPr4a2c7C-XMID26ek3__9Wcxxa1wo7c4aAsGSEALw_wcB

I'm sure some of the guys will know more about the inner workings of these.

[Freightrain]

There is likely just an o-ring on the shaft and a paper gasket on the back.  Not much to them.  Used to mess with mine til I got it fixed up good years ago.

 

Yours is slightly different then mine.  Mine has 4 air lines.  I tried to order a new valve once from Watts and it was not the same, thus fixed mine.

[doubleclutchinweasel]

I was hopin’ you would see this one, ‘Train. 

[Full Floater]

Thank you guys.   I just ordered that one from HD pros.   We'll see how she goes!

 

[Geoff Weeks]

Book mark "Rome Truck Parts" for those Trico motors. If you need motors or a rebuild they are the only ones that seam to know much about the old Trico's. Because those use air to park (when the button is pushed in) and I don't think you said where it is leaking from, it could be the valve in the motor as well.

http://www.rometruckparts.com/

[mowerman]

That’s good to hear. Mine does the same thing that’s leaking from the switch in the off position. Bob

[mowerman]

I did hear from the parts man  at watts  you can pull them apart and clean them up and replace O-rings. I don’t know that’s what this guy said and he’s not there any longer. Bob

[mowerman]

He also said a brand new wiper motor was $800 and that was 10 years ago. Ouch.!!!!!!!! Bob

[h67st]

On 9/13/2023 at 8:38 AM, Geoff Weeks said:

Book mark "Rome Truck Parts" for those Trico motors. If you need motors or a rebuild they are the only ones that seam to know much about the old Trico's. Because those use air to park (when the button is pushed in) and I don't think you said where it is leaking from, it could be the valve in the motor as well.

http://www.rometruckparts.com/

The guys at Rome are excellent, I got pivots, arms, blades, etc. from them. They have lots of NOS stuff at good prices.

[Full Floater]

On 9/22/2023 at 4:11 AM, mowerman said:

I did hear from the parts man  at watts  you can pull them apart and clean them up and replace O-rings. I don’t know that’s what this guy said and he’s not there any longer. Bob

Take the switch apart or the motor?   Id like to dig into the motor (which works fine) to clean it up and make sure its good for a while.

[Geoff Weeks]

If you do take apart the Trico motor, be very careful. Parts are not readily available, as Trico stopped making them in the early 80's. O rings will not be the problem, but the paddle seal and little parts, like the reversing valve may be hard to find. I have two of these motors that came from different trucks. I have not been through them myself, as Sprague HP 100's were the replacement in my trucks for the Trico's and they were easy to source. I like the Trico better, but the parts issue on a truck in service, was enough for me to change while I could. 

 I was going to send off my Trico to Rome for overhaul, but never did as I had plenty of HP-100's and could overhaul them myself, and no problems if something broke as parts or parts units were easy to come by.

If you only have the ones for you truck, proceed with caution, one lost or broken small part may leave you with no options.

I should add, there is nothing difficult or special about air motors, they are simple devices, but anything without a source of parts can become a big problem, not because of the complexity but the lack of some small piece.

Edited September 27, 2023 by Geoff Weeks

[Full Floater]

On 9/27/2023 at 9:04 AM, Geoff Weeks said:

If you do take apart the Trico motor, be very careful. Parts are not readily available, as Trico stopped making them in the early 80's. O rings will not be the problem, but the paddle seal and little parts, like the reversing valve may be hard to find. I have two of these motors that came from different trucks. I have not been through them myself, as Sprague HP 100's were the replacement in my trucks for the Trico's and they were easy to source. I like the Trico better, but the parts issue on a truck in service, was enough for me to change while I could. 

 I was going to send off my Trico to Rome for overhaul, but never did as I had plenty of HP-100's and could overhaul them myself, and no problems if something broke as parts or parts units were easy to come by.

If you only have the ones for you truck, proceed with caution, one lost or broken small part may leave you with no options.

I should add, there is nothing difficult or special about air motors, they are simple devices, but anything without a source of parts can become a big problem, not because of the complexity but the lack of some small piece.

Excellent advice.  Thank you

[Full Floater]

Does it do them any good, to disconnect the air supply line to them and give em a squirt of some form of oil from time to time?

[Geoff Weeks]

Can't hurt, air tool oil, but I never did.

[Freightrain]

My biggest problem with the motor was it was gummed up and the reversing valve was sticky.  Pulled it out, cleaned the reversing valve, cleaned the linkage and the main piston/bore and bolted it back in.  Some new airlines and it will throw the blades off it runs so fast now.

[other dog]

On 9/22/2023 at 7:13 AM, mowerman said:

He also said a brand new wiper motor was $800 and that was 10 years ago. Ouch.!!!!!!!! Bob

holy mackle! On the last truck I drove with air wipers, a '77 F model, I would disconnect the air line going into the motor and pour some air tool oil in it periodically, like you put in an impact wrench. That seemed to help them. 

[66dc75]

My wipers quit on my 67 R model. Took the motor apart, cleaned the mounds of gunk out, lubed and re assembled. Has been working  perfect for the last 3 or 4 years.  

[70mackMB]

Ha! Any extra oil in my wipers runs down the windshield. A sign of a true MB!  lol     .....Hippy 

[Geoff Weeks]

That is one nasty looking air wiper. What does your compressor/air tanks look like?

[66dc75]

22 hours ago, Geoff Weeks said:

That is one nasty looking air wiper. What does your compressor/air tanks look like?

Surprisingly clean never get any oil out of the tank.drain

[mowerman]

On 9/27/2023 at 8:19 AM, Full Floater said:

Take the switch apart or the motor?   Id like to dig into the motor (which works fine) to clean it up and make sure its good for a while.

Sorry I missed this parts man  was talking about the switch that is what is leaking on mine as well. I have not done anything with it yet.

[mrsmackpaul]

On 10/3/2023 at 8:09 AM, Freightrain said:

My biggest problem with the motor was it was gummed up and the reversing valve was sticky.  Pulled it out, cleaned the reversing valve, cleaned the linkage and the main piston/bore and bolted it back in.  Some new airlines and it will throw the blades off it runs so fast now.

Turn the knob back, as in twist

I never new this as it rarely rains were I live so I just the wipers were rubbish for decades

Sent the motor off to be rebuilt, refitted it and no different 

Phoned the bloke and he said to increase the pressure 

"Mate the trucks not gunna go any higher than a 115 psi"

Turn the knob I was told, he had to really explain it to me

What a result lol

 

Paul

[Freightrain]

It is variable speed but with no gunk and new air lines if you crank the knob to the right it really flies now.  Before it barely made a full swipe as it hesitated a long trying to fight through the stiff crap jamming everything.

[Geoff Weeks]

Also there is an adjustable restriction on the exh side of the motor. It keeps the motor and blade from "flopping" too fast to the other side. Keeping pressure on both sides of the motor piston keeps the speed steady regardless of load.

 Too much restriction (back pressure) and the motor will be slow or not move at all, too little and it will slam side to side too fast. The control knob can vary the speed of the sweep but the exhaust restriction can also.

On full speed, with a wet glass, you want it to move quickly but with no "flop".