Pneumatic washer pump - repair or replace with electric?

richard5933 · October 17, 2017, 07:23:42 PM

The pneumatic washer pump on our new 4108 doesn't seem to push washer fluid to the windshield. I hear air moving through the switch when I press the button and I think it's making it to the washer reservoir, but nothing is being pumped out.

Anyone have an idea if these things are worth repairing or if it's a more practical option to just replace with an electric pump?

If repair is possible, does this use a pressurized reservoir? If not, what's the basic way the thing works?

Thanks.

Richard

luvrbus · October 17, 2017, 07:33:29 PM

Those are a air diaphragm pump the reservoir are not pressurized,if you want to keep the air you can get the new style (turbine) pump from www.rometruckparts.com

Iceni John · October 17, 2017, 07:58:51 PM

I had (past tense) a Sprague air-operated washer pump that defied all my attempts to fix it and make it work right. It hissed, gurgled, bubbled, even squirted fluid back onto my foot from the push valve, but just couldn't move enough fluid onto the windshield to make any difference. So, I replaced it with a cheapo electric pump from Pep Boys, and I modified a push-switch to accept the original Sprague knob. It now looks original but works excellently. So well, that I couldn't help but install a second pump, this one for some extra nozzles above the windshields! I now have four nozzles (two fixed and two on the wiper arms) that DRENCH the windshield. No more pathetic dribbles for me.

John

Oonrahnjay · October 17, 2017, 08:33:30 PM

Quote from: Iceni John on October 17, 2017, 07:58:51 PM... No more pathetic dribbles for me. John

Yeah, I remember when I was young ....

Dave5Cs · October 17, 2017, 10:32:52 PM

Oh not me. On our 8,874 mile trip we just finished. I just Loved to stop for fuel and use the clean water they had at Love's with the long arm squeegees with all the soap they put in the water. It didn't leave big white strips on the windshields and my arms and shoulders felt so much better the next day. When the sun was up and I used the water it wouldn't dry faster than I could use it and then drip down the front of the coach. Why would i fix my water tank and pump, Seriously.

chessie4905 · October 18, 2017, 04:06:17 AM

Just bought a new air operated pump from Luke for mine. Came complete cap and all except for jug. He also sells seal kit for them. If your nozzles are removeable try cleaning them or use a straight pin.

lostagain · October 18, 2017, 07:04:39 AM

I overhauled mine. Mostly cleaning the mud out of the jug and the lines, and I forget what else. It's been a while... But it works good enough. Takes a little while between pumps for the system to pressurize to squirt again. My memories of driving bus in the winter in the 70s is that most didn't work, so you only used the wipers if you really had to. Or when the highway is dirty, you have to time it just right to catch it when you meet a semi that spays enough dirty water for the wipers to actually wipe the grime off...
We even had to stop on the side of the road at times to wipe the glass with snow balls...
I am amazed at the late model coaches now with modern electric wiper/washer systems that work just as good as in a car. Driving is a lot easier nowadays.
I suppose you could install an electric pump.

JC

Scott & Heather · October 18, 2017, 09:04:25 AM

Funny this is being brought up, I'm renovating my washer system right now too! Tossing the air system and just using a pump. Makes more sense to me. Just have to figure out a way to connect nozzles to the wiper arms

Sent from my iPhone using Tapatalk Pro

windtrader · October 18, 2017, 10:09:13 AM

Just tap into the pressurized fresh water system. Add a faucet handle on the dash and you're all set.

richard5933 · October 18, 2017, 11:31:33 AM

I decided to give repair a try. New one on the way from Luke.

Richard

1974 GMC P8M4108A-125 (Current bus)
1964 GM PD4106-2412 (totalled Sept 2017)
Located in beautiful Wisconsin
KD9GRB

buswarrior · October 25, 2017, 10:33:11 AM

Some cheapo electric washer pumps will leave a busnut weaping tears, at about the same dribbling rate...

The air units can really move a lot of juice, through large hoses.

It all depends what "fixes" have been done to your coach, and what you will need to "unfix"...

Happy coaching!
Buswarrior

richard5933 · October 25, 2017, 12:33:18 PM

I did get the new pump from Luke. He sent the part that goes inside the bottle. I'm hoping that is what's bad. There is of course also the push button control and the piece on top of the bottle lid, and I have not thoroughly checked those. The bus is a bone stock unit - it was originally owned by the owner of a charter company who I'm told was somewhat of a bus enthusiast. Other than what Custom Coach did with the interior and in the bays, the bus systems themselves have not been altered or touched. In fact, the bus even has the original shields under the engine & tranny.

The bus is in the shop right now have some inspections and routine maintenance done. I'll work on this some more in a few days when it's back at my place.

Thanks for the information.

luvrbus · October 25, 2017, 01:33:17 PM

Was that Charles Wotring bus ?

richard5933 · October 25, 2017, 01:56:46 PM

Quote from: luvrbus on October 25, 2017, 01:33:17 PM
Was that Charles Wotring bus ?

The name doesn't sound familiar, but then again I really don't know. The charter company was called Super Service. The bus still carries the original livery colors and logo.

pabusnut · October 25, 2017, 04:00:21 PM

I think Charlie's bus was a lovely chartreuse or turqois. Royal Coach was the name of his outfit I think.

I have not seen it in person and now I can't find a picture.

Steve