I swapped my calipers with v6 units and ceramic pads. I aslo put in a new master cylinder from fj80 1 inch bore. Now my pedal is hard as hell to push down and won't fully stop my vehicle. I've checked for vacuum leaks with no luck. The brakes worked fine before the swap just a little weak so I don't think it's the booster either. I'm stumped and out of money.

 

i'm not sure where to start looking because everything is new and not leaking.

 

did you check your push rod adj?

 

how do I check that. I haven't touched it since replacing the mc.

 

if it's hard to push the pedal would it need to be adjusted forward or backward.

 

under your dash, there is an adjustable push rod that goes into the booster. Loosen the jam nut and adj the rod as needed. I forget how much but there is a certain amount of play that needs to be in the pedal

 

you dont want too much play but you dont want it tight either

 

Go to the parts store and get the MC for a V6, preferably same year as your V6 brake parts. You have a mismatch and the MC bore is too small. I think the V6 has a 1 1/4 inch bore. And, read the MC install instructions that come with it to make sure the push rod is not holding pressure in the MC, etc.. Return the ceramic pads and get OEM metallic and turn your rotors.

 

i adjusted the push rod and it did help but the brake pedal is still hard and it doesn't stop like it should. if i try to lock up the brakes on gravel they only lock up when the pedal is mashed to the floor and then it's still weak.

 

I agree with seaire, get the correct master cyl and adj the pushrod. Also make sure your entire brake sys is bled thoroughly.

 

Is this like the MC you have?
http://www.marlincrawler.com/htm/brakes/mcylinder.htm
If so, Marlin Crawler says it will work.
I think you got a bad MC.

 

i got the mc from trail gear and they told me with my upgrades to my brakes this was the correct one. if i get an mc from the parts store for this year of brakes will i be able to tell the difference between my 85 stock rotors and calipers and my new 92 calipers and vented rotors. all i'm trying to do is increase my braking power. future plans also include rear discs.

 

mine looks identical as that one part # and everything

 

then I think you got a bad MC, I'd exchange it

 

thanks for the help guys. its hard to find anyone who will respond.

 

Did you bench bleed the MC before installing it?

 

i did bench bleed it. when i bench bled i couldn't get rid of the bubbles. maybe i didn't do it long enough. i push the piston in about 10-15 times. wouldn't air in the system make the pedal soft instead of my problem of being hard as hell.

 

Air in the brake system will make the brake pedal feel spongy.

 

Ok, here's the thing, this is all about mechanical advantage. If you increase the size of the piston in the mc, then in actuality you are decreasing the amount of force acting on the fluid. As a result it takes more force acting on the pedal to get the same amount of braking, not less. The v6 mc's use a different brake booster to compensate for this difference. They use dual diaphragms which gives twice as much vacuum as the single ones. You need to upgrade the booster to the v6 style and then you will be ok. The parts you have should be just fine. Just change out your booster.

 

just what I was going to say ... exactly !

swap the booster .

It's funny .. these companies sell you this stuff but dont tell you what you gotta do to make it work . HUH ! nice.