Bad Proportioning Valve?

georides · 02-25-2009, 12:03 AM

Guys, thanks for the replys,

I assumed it was called the proportioning valve re this ebay post, mine sort of looks like this:

eBay Motors: 1983-86.5 TOYOTA SUPRA MA67 BRAKE PROPORTIONING VALVE (item 130253416595 end time Mar-06-09 14:08:09 PST)

We removed it today, bought two unions and a short ready-to-bend piece of brake line and actually successfully bypassed the valve, but we do have all the lines, if we decide to put it back.

We started to bleed the rear wheels, it made a big difference, good solid line of fluid, pressure build up when pumping and release on bleeder open (which have been replaced, thanks for the pic)

We attempted bleed of front, got the same squirting froth that we had on the rear wheels, now it makes sense that we had switched the outputs.

I assume now that the problem is the master cylinder, which was my original assumption, though because the "toyota kid" at work said that it was federal mandate since the '70s the cars were diagonally split on brake cylinders, this way if there was a leak at least you'd have front and back, but remembering replacing a line of my uncle's GMC Sierra, he had a "T-Split" as seen in your schematic.

Tomorrow I order a new MC, should have done this first out. pics later

02-25-2009, 12:03 AM	#5
georides Stock Join Date: Feb 2009 Location: North Jersey, USA Posts: 9	Guys, thanks for the replys, I assumed it was called the proportioning valve re this ebay post, mine sort of looks like this: eBay Motors: 1983-86.5 TOYOTA SUPRA MA67 BRAKE PROPORTIONING VALVE (item 130253416595 end time Mar-06-09 14:08:09 PST) We removed it today, bought two unions and a short ready-to-bend piece of brake line and actually successfully bypassed the valve, but we do have all the lines, if we decide to put it back. We started to bleed the rear wheels, it made a big difference, good solid line of fluid, pressure build up when pumping and release on bleeder open (which have been replaced, thanks for the pic) We attempted bleed of front, got the same squirting froth that we had on the rear wheels, now it makes sense that we had switched the outputs. I assume now that the problem is the master cylinder, which was my original assumption, though because the "toyota kid" at work said that it was federal mandate since the '70s the cars were diagonally split on brake cylinders, this way if there was a leak at least you'd have front and back, but remembering replacing a line of my uncle's GMC Sierra, he had a "T-Split" as seen in your schematic. Tomorrow I order a new MC, should have done this first out. pics later