Ok... I installed the new '94 v6 IFS calipers and Landcruiser Vented rotors with ceramic brake pads... everything fit and it looks good... I had to use spacers to get my wheels on .. but no biggie. I then took the load proportioning valve outta the system and isolated one brake line to the back and patched it into the "T" on the rear differential. the front of this line goes to the rear outlet on the stock master cylinder. From the front outlet on the master cylinder the line goes into a "T" that mounts on the bottom two studs that hold on the master cylinder and go to the two front wheels. In theory the front outlet of the master cylinder goes to the two front wheels and the rear outlet of the master cylinder goes to the two rear wheels. I checked and re-checked this to make sure this is exactly as I described. I then bleed the brakes out very well using the tube and mason jar method starting with the longest line and working to the shortest line .... I did this several times ... key word there is Several. MY PROBLEM... weak brake pedal ... seems like the system needs bleed again but I have bleed and bleed and im sure that I have no air in the lines. QUESTION... Is this the problem that they advocate the FJ80 non-abs master cylinder to fix?? IF so, What year? NEXT QUESTION ... has anyone removed their load sensing proportioning valve in this fashion and had a simular problem?

 

i bet your master cylinder isnt big enough to handle the upgraded brakes. maybe upgrade to the one from the FJ80?

 

the v6 calipers need more fluid volume than the stock 4 cyl master (im assuming) can dish out. 89 mac is dead on with the fj master upgrade. (again assuming you have a 4 cyl truck.)

 

I did the caliper upgrade on my FJ40. I installed a 1" bore master cylinder 94 non ABS 4 runner) and mine work great. I think the 4 cyl master cylinder is only 7/8" (?). I ground down the fins on the caliper instead of using spacers

My cruiser does not have the rear valving though.

How did you "remove" lspv? Did you disconect the tube from the front brakes to the valve? (the is another T on top of pass side frame rail by front wheel)

 

It's the LSP valve,(load Sensing Proportioning valve) There are companys that sell a race type, manually adjustable proportioning valve that you dial in by turning a nob. I had the same problem after removing my LSP valve. I know for sure that Front Range Off Foad sells them and Ive seen them other places to but cint think off the top of my head. The new valve will firm up the brake peddle without having to buy a new master cylinder.

 

I got it... Just needed bled lots more.

 

Glad you figured it out before wasting time and $ on the MC upgrade.

Everyone assumes you must change to a larger MC when doing that swap because that's what they read. As you've found out you don't. I run 6 cyl IFS calipers AND larger rear drums (IFS rear swapped in) on my 84 Runner and the stock MC stops my 36" tires just fine.