windshield wash problem, old pneumatic system on the blink Options

[Yoei66]

I acquired some new hoses, connections, nozzles, ect lately for my original pneumatic powered windshield wash
system. I could never get the system to work strong after the PO caked the spray nozzles with multiple waxing, and
leaky hose between the tire and the wash tank. It would only spray out of two of the four nozzles for a few hours,
before the tire lost pressure, but still worked. Yesterday I put a fresh hose between the tire and tank, and replaced the
spray nozzles. Now I have a new problem. Once the tank is pressurized to 42psi the system will spray for about 1/2
second then it stops working. The tank is still pressurized, and I detached the hoses from the spray nozzles, still no
spray. Every time I drain the pressure from the tank, and re-pressurize I get one interval of 1/2 second spray, then
nothing. I took the tire hose and hooked the system up backwards. I successfully blew bubbles in the wash tank when
pulling on the wash wand with this attempt. I thought this would clear the system with a backflush. I them hooked the
system back up normal, except for the spray nozzle hoses jest hanging free to eliminate the new nozzles from the test
I still get the same 1/2 second of wash, requiring a pressure drain reset for another 1/2 second. Is this indicating a bad
steering column control. I’m considering rigging up an electric pump system, but am willing to try a few more things
to get the original, quirky system working again.

[ChrisFix]

I just finished replacing all the hoses on me washer system yesterday. There are check valves below each of the spary nozzles that may be bad on yours. If you have them, try bypassing to see what happens. The valve switch in the steering column is just a manual valve that has a small pin witch the wiper switch lever presses against when you pull it forward. I can't think that it could malfunction in the manner you describe, but if you pull the steering wheel and the switches, you could test it easily enough. The system runs a pressurized tube from the bottom of the washer bottle to one side of the switch in the steering column. The other side of the switch is un-pressurized and runs to the nozzles. Pretty simple. There is supposed to be a pressure control such that it won't work below 29 PSI (I think) so that you don't run down the spare. If that wasn't working correctly, it could conceivably cause the problem you describe.

If you end up taking the steering wheel off and the switches out, and haven't done this before, let me know and I can fill you in on the secrects that only doing it will teach you.

[Yoei66]

Chrisfix
This is hilarious! were across the country from each other, working on the same 914 projects, on the same weekend. I did discover that after the tire pressure dropped to 30 psi, that no more air came out of the tire, to the tank. the control apears to be in the cap for the tank. I also noticed the check valves, and removed them for testing. After trying again this afternoon the washer fluid now continues a slow leak out the spray nozzles until the tank goes dry. I’ve determined that the manual steering valve switch is the source of the problem. I had to come to a decision as I looked on e-bay and saw a brand new, unused 914 washer/wiper arm assembly going for $15, with ten minutes left on it's auction. After some thought I instead bid and won two Honda Civic washer pumps for 99 cents total. I hate to do it, but I’m going to convert to an electric pump, not look back, and make the pump switch look like it belongs.

[ChrisFix]

Yeah, the brotherhood of 914s!! I really like the archaic 'spare tire to wash your windows' technology - it's just so goofy you have to love it. Having to disassemble half the car to replace the switch hoses left me second guessing my decision, but once it was all back together, I'm happy I left it that way. You're correct, the wash bottle cap cuts off the pressure to keep the tire from going flat. If you have leaking from the nozzles, then you're also correct that the switch isn't making a complete seal to hold the pressure. In my car, I had the classic puddle in my lap from the hose giving out, so once that was replaced, all was well. Good luck with your retro-fit and again, if I can be of any assistance with this let me know.