[MrRocky]

Recently done a front disc brake swap on the lj80, rebuilt the calipers (cleaned pistons looked ok). Also installed a baleno/sierra master cylinder prior to doing the disc swap and worked well with the drum front setup but seem to be getting grabbing on the front.
After a 20 min drive the front brakes and rims are super hot and gets progressively worse to almost undrivable after 30 mins or so, feels like im dragging a ton behind the car.
Ive replaced the pedal box bolt and adjusted the brake switch, dismantled and regreased caliper pins ect...
Any ideas ? Should i have retained any bits of the old master or do i need to upgrade the spring on the pedal ?
Running out of stuff to replace

[shep]

I had a similar issue with a shitbox vitara. I flushed all the likes with fresh fluid and it fixed it.

[MrRocky]

All the fluid is new x 3
Bled it all when i put new drums on, again when discs went on and again when i pulled calipers off to check.

Its odd the pedal is what id consider spot on then gets progressively firmer until its rock solid after 20 mins.
Like the fluid cant get back to the master ?

[sideways]

My Sierra did the same, new master cylinder fixed it.

[fordem]

It sounds like the booster/master cylinder pushrod may be incorrectly adjusted - if the primary piston in the master is not allowed to return fully it may block one of the ports between the cylinder & the reservoir preventing fluid from returning to the reservoir.

The above is more of a "general brake" thing and not specific to the Vitara, and I've never looked to see if the Vitara setup has an adjustment on the pushrod, but that's where I would be looking - check the FSM and see what it has and then check yours to see if it is correctly set,

[MrRocky]

I got another master here might swap it on the weekend see if makes a difference

[MrRocky]

The lj80 pushrod is not the adjustable variety

[MrRocky]

Ok swaped in another master cyl and problem is exactly the same. Theres not much that isnt new in the whole system.
Any ideas

[fordem]

Try spacing the master cylinder away from the firewall - I'm thinking something like a gasket out of 2mm cardboard - the idea is to create a little more room to make sure the primary piston can return freely - same as the pushrod adjustment that isn't there.

[MrRocky]

I was thinking something along those lines.
Might try knock up an adjustable pushrod

[MrRocky]

Cut 10mm off the pushrod - problem solved
Still a little odd theres no mention of having to do that in anyones tech write up