Brake Battle -- Mushy-No brakes

[Bear80]

I also replaced the lspv on another '86 and '87 4runner along with the rear cylinders, m/c's for both and they both brake great. I just cannot figure out why my truck is being a bitch.

 

[Bear80]

First thing i would do is replace the rear wheele cylinders. its cheap and can be a big problem. second thing: buy one of these http://www.marlincrawler.com/htm/brakes/mcylinder.htm

Man I don't mean to 'knock everything you bring up but the 1" bore is not the answer. Marlin is addressing the issue when you have the 8" drums and older non vented rotors/calipers. My truck has the larger rotors, and drums having no real need for a larger m/c. ALSO a larger bore m/c will more MORE fluid but the 13/16" m/c creats more PRESSURE. Calipers require more fluid movement beacuse they are larger than wheel cylinders. Which is why toyota uses 13/16" cylinders for use with rear wheel cylinders.

 

[WristPin]

ok, i gave up reading around post 25.

how I can tut out for hours? i dont know. besides the point.

this may have been covered:

my truck does the same thing. it doesnt bug me and i am broke, so i cant fix it anyway.

the LSPV is leaking. you cant see any fluid on the outside, cause the boot covers it.
get some snips, and snip the wire holding it on, and inspect it, or poke a hole in the boot.

i havent added fluid in months, as it goes down very very slowly.

 

[WristPin]

also, this may be an old trick to you, but i'll mention it any way.

if you clamp off the rear hose, the two front hoses, you eliminate the possibility of problems in the wheel cyls and calipers.
the pedal should be hard.

to find the problem corner take off one clamp at a time after checkin for pedal feel each time.