Everyone:
Am working on the dash for my XK120, S/N S677519 and wanted to get the windscreen washers to really work again. Replaced all the tubing. The old stuff simply crumbled when you breathed on it. Bit of a PITA to get all the hoses connected, but none-the-less, that’s done. The control valve on the dash was the next troublesome issue. Was able to find a new one at Barratt and had a question about plumbing it up. In Viart, page 320, it describes the washers. The control valve is identified as P/N C.5472/7. Amazingly, that is the same P/N that Barratt had on their computer. The valve is supposed to make a tight vacuum seal unless you push in the button, in which case, the intake manifold vacuum is supposed to suck the pump diaphragm up. Then when you release the valve, the pump is supposed to squirt fluid onto the windscreen.
My question is about the plumbing. In Viart, they show the valve with two fitting and the whole thing looks like a “T” with one fitting on the straight run and one on the branch. There is more detail if you google bobine jaguar xk windscreen washers detail. My question is about the plumbing connections. In my car, the intake manifold is connected to the straight run of the control valve and the branch goes to the pump. Viart shows it the other way. When I tested the valve, it made a tight shutoff with vacuum applied to the run fitting, but not on the branch, leading me to think the plumbing on the car was run correctly. Just wanted to check since Viart is a really good reference and it differs from the car and from how the valve seems to work.
Thanks Much,
Cliff