Re: mystery switch and mystery noise

Posted by HH56 On 2011/12/18 11:10:44

On the plumbing, can't say which port front or back as pumps may be different. Remove the two hoses from vacuum side of pump. With engine running use your finger to see which port has suction. That one goes to wiper motor. The other goes to the intake manifold or carb.. The way it works is normally the intake manifold is stronger and just pulls air thru the vacuum pump. When engine under load and accelerator more open, that vacuum source becomes weak and pump is stronger so it does most of the work.

On the linkage, lay a ruler or some other narrow but STRAIGHT item on the head that is long enough to cover two of the ridges on head and extend out over manifold the way the gauge is shown in picture. Use a tape measure or another ruler to measure from the BOTTOM of the straight piece to the center of the rod. It should be pretty close to 2 3/4 inches. The measurement will vary a bit when other adjustments are made but should be very close. If you can't keep the ruler flat across the head and measure at the same time, then maybe another set of hands would help.

On the bottom end, remove the cotter key and slide the pin and rod off lever. Ensure the top end measurement is still correct then see if you can move the lever more to rear without compressing the spring. IIRC, the spring is not terribly stiff so won't require a lot of force to compress it. Use a fine touch. If you can move lever far enough to rear before reaching spring that the pin and rod won't go back in the hole then it needs adjusting. If you do need to adjust, follow the instructions. If the pin goes back in, then leave everything alone.

On first examination, if any of the measurements or adjustments are really far off, don't change anything until you find out what is not correct. There is another turnbuckle on accelerator pedal side that also comes into play and a bent rod could also be present. This is one adjustment that needs to be done correctly.