tightness of switch to brake fluid distribution block

[Al R.]

How tight should the safety switch be to the body of the brake fluid distribution block on a 67? I'm looking for possible areas of air being sucked into the brake fluid lines. Also, is it possible to overtighten the switch so that it could prevent the shaft inside the block from moving side to side and thereby cutting fluid flow to either the front or rear brake calipers and also prevent activation of the brake light on the dash ? As usual TIA everyone! Al

[John H.]

Re: tightness of switch to brake fluid distribution block

How tight should the safety switch be to the body of the brake fluid distribution block on a 67? I'm looking for possible areas of air being sucked into the brake fluid lines. Also, is it possible to overtighten the switch so that it could prevent the shaft inside the block from moving side to side and thereby cutting fluid flow to either the front or rear brake calipers and also prevent activation of the brake light on the dash ? As usual TIA everyone! Al

Al -

It's highly unlikely, as the distribution block is steel and the switch terminal is brass and plastic; also, there is no valving function inside the switch - fluid from the front system can't get to the rear system, and vice versa. The spool between the two systems is sealed at both ends, and simply shuttles in either direction depending on which system loses pressure and makes contact with the switch to illuminate the warning light; nothing in the block can interfere with the flow of brake fluid to either system.


DiffPressSwGM800.jpg

[Al R.]

Re: tightness of switch to brake fluid distribution block

Thanks John, the diagram was most helpful in understanding the workings. Al