Early Bay Windshield Washer mod (part 1)

All bus content today. I'm going to go over how to modify the early bay-window bus windshield washer system from the original air-pressure system to one using a more modern pump. Well, this got really long, so I'm splitting it up into multiple posts instead.

Original Set-Up
For starters, we'll reference the picture on the RAtwell site (re-posted here). Although the system in the picture is for a later bay, most of this is the same for the early bus. The biggest difference is in the valve in the lower left corner. The late-bay windshield wipers and washer controls are on a stalk attached to the steering column. The early-bay controls are a switch contraption on the dashboard next to the hazard light switch. It is round, and the user twists the knob to turn on the wipers... and pushes a button in the center of the switch to activate the valve.

thx RAtwell. you're amazing

The valve allows pressurized water, air, soap through the lines from the bottle out to the nozzles on the front of the bus. The bottle on the far right sits just in front of the front passenger's foot-well. The long hose runs out the bottom of the tank and ties into the valve I just described. The short hose that looks like its coming out of the top of the bottle is, again, a little different from the early-bus, but the purpose is the same: connect a bicycle pump to that so you can pressurize the tank, and, accordingly, the system.  In the early bus, the air hose attaches to the tank like the other hose does on the bottom of the tank: press onto a nipple and them cinch it down with a plastic threaded nut.

So, with that orientation, you can probably imagine how well the system works or doesn't work after 40 years of recurring owner neglect. On my bus, the rubber lines had been cut out or at least cut up so pumping the tank just sprayed its contents all over the electrical a behind the dash. Fun. The tank doesn't usually fail, but the valves can. Or so I've been told. There are a few changes to modernize the system.

Scope of Mod

McMaster switch

First and most important is how to incorporate an electrical switch without disrupting the original dash or spirit of operation? The original button should remain with magic behind it so it at least looks the same. To work, you need a SPST (single pole, single throw) NO (normal-open) biased (push-on, release-off) switch. The switch in the door is kind of like this except it's NC (normal-closed) and creates a circuit when the button pops out. I spent quite a bit of time researching this, and what kinds of switches were readily available. You can get a cheap one, or even a set of 2 or 4 from RadioShack.

They will eventually fail, and "eventually" may not be that far off based on how much current they can handle. I was concerned with how hardy these switches are, especially with how hard the switch will be to get to once installed. Instead, I paid as much for one McMaster-Carr switch as 4 RadioShack ones. This is why I didn't solder wires and instead used insulated connectors: I didn't want to fry the switch with a soldering iron.

washer pump 1J5 955 651

Second, if we want the VW to remain totally a VW, we should use a VW pump. That's actually pretty easy, and yes, I know I have already angered the purists with my bus, but this modification shouldn't be verboten by them, IMHO. Anyway, I got a pump that fits a modern VW (part #1J5 955 651). The vanagon pump has larger more common pins for the electrical side, so it might be a better, easier bit for electrical. I had the modern pump on-hand, so there ya go. The rest of the system remains the same. The rubber hoses are replaced, the nozzles replaced. This includes the air-pressure hose; replace it with a basic hose and point the open end up behind the glove box for an air source.

Parts List

So, before we start doing, we need some parts. The pump, the switch and the nozzles may need to be ordered. Its possible that the pump and nozzles are available locally, but at the very least the switch will need to be ordered. I got my nozzles at the local VW parts shop (DIP). Part numbers (in parenthesis)

Washer pump (1J5-955-651) or you could use one from a vanagon (431-955-651)

2-pin plug (1J0 973 702 should work) if you used the same pump as I did

McMaster-Carr SPST/NO 12V switch (7397K25) link here

3 Phillips-head screws. not bolts.

6' rubber washer hose
3/4" x 10' polypropylene strap. you'll only use about a foot of it

2 washer nozzles (211-955-993)

Some insulated electrical connectors (1 ring for ground, 2 tiny female for the switch and 2 standard female for the pump if you used a vanagon pump)

That's it for today.  Doing the whole job in one post was just too much.  I hope everyone had a hapy, healthy and restful holiday season. Have a safe and wonderful new year.