BJ73 brakes @#%$@#$%#@@#$@#$@#$@#%`

[amaurer]

I'm losing my mind over a brake problem with my BJ73.

About 5 months ago I replaced all the pads and shoes. Adjusted, drove, everything was great.

About 2 months ago something started to happen where, seemingly randomly, but usually at the end of a long drive, the pedal would intermittently feel "different." Stopping power wasn't changed, but the pedal would travel further before it became firm. The condition would come and go from one moment to the next.

About a week ago I dove in to fix it. I inspected everything and found no problems, readjusted the rears (just tight enough to complete a full revolution of the wheel without dragging), and fixed the LSPV for my lift springs by extending the linkage a bit.

The test drive was great, nice firm pedal. The next day, however, after 30 miles the right rear brake was HOT HOT HOT. I had no tools small enough to adjust it there so I turned around immediately, but before I could get home it was obviously hot enough to boil the fluid and the pedal was all kinds of spongey and I had effectively no rear brakes at all.

I dove in AGAIN to reinspect and found that the adjuster on that side was displaced - it wasn't sitting in its slot. I'm sure it wasn't like that when I buttoned everything up. I poked it back down, readjusted (looser this time) and tried once more.

Sure enough, after 30 miles, the brake is hot and stinking again!

I backed the adjuster off about 10 or 15 clicks thinking it was just an adjustment problem and I'd just live with the sloppy brakes to verify that was the issue.

Worked for about 3 days... last night that brake started shuddering on the way home, and sure enough, when I got to the driveway it was hot!

ARGHGHHG @%$^%$@#%^$#^%#$@%#$##$^@$@

Any ideas?

 

[Radd Cruisers]

Are the parking brake bell-cranks resting against the backing plates when the parking brake handle is all the way down?

Sounds like a cable / bell crank / equalizer issue. It is VERY common to find these have not been properly adjusted and taken care of.

~john

 

[roscoFJ73]

Sounds more like the hydraulic side of the brake system to me.How old is the master cyl?

How bigs the lift? On my FJ73 I had a 2 1/2 inch lift and left the LSPV as it was and never had a problem.

TIP when adjusting rear brakes ,disconnect drive shaft.Otherwise it can be difficult to hear/feel the brake shoes rubbing on the drum.

 

[hotgemini]

Yeah, I'd be looking at the master cylinder too. Sometimes a nick in the seals in the master will flap about and seal intermittently.

 

[amaurer]

I took the brake apart again.

One thing I forgot about was: I replaced the shoe with aftermarket stuff. The pins that came in the aftermarket shoes were different than the OEM pins but it didn't seem to be a large enough difference to make trouble. Also I found the the pins themselves are now loose in the shoes - the press fit has apparently worn down or something.

I don't know if this could explain my problems - it doesn't seem like it should - but to be safe I'll get some new OEM stuff and pull out the aftermarket crap. The worn pins need replacing anyway.

 

[prado t]

Are the parking brake bell-cranks resting against the backing plates when the parking brake handle is all the way down?

Sounds like a cable / bell crank / equalizer issue. It is VERY common to find these have not been properly adjusted and taken care of.

~john

Yup , Thanks to John @ Radd I now have brakes and good brakes too. Thanks s John !

 

[amaurer]

Replaced shoes/pins/springs with new OEM parts. Parking brake adjuster mechanism works nicely.

Still have the problem!

Pedal feels soft intermittently, though perhaps most often when pointing downhill. Often behaves normally on flat ground.

However at all times, even when it feels normal, a good stomp on the pedal will lock up the rears, but the truck still stops poorly. Almost like the fronts aren't doing enough work. Or the rears are doign too much, etc.

 

[roscoFJ73]

So its sounding like the front calipers are not doing their job or they have air in them. Everything else has been done and if it was the master cyl ,then the back brakes would be performing badly too.
Or your discs have exceeded their wear limit and the caliper pistons are being pushed past their limit.

 

[amaurer]

So its sounding like the front calipers are not doing their job or they have air in them. Everything else has been done and if it was the master cyl ,then the back brakes would be performing badly too.
Or your discs have exceeded their wear limit and the caliper pistons are being pushed past their limit.

Bled the fronts too. A lot.

The front pads are only 3 months old and they're probably 3/8" thick still - the calipers are nearly fully compressed. I didn't measure the rotor but the calipers are definitely not over extended.



The only thing I can think of is maybe the LSPV is sending too much juice to the rear.

 

[LJjuz]

You could try taking out the LSPV and replacing it with a Willwood Brake Proportioning Valve? Thats what I did for my LJ71 as the LSPV was seized. Very simple job, hardest part was making a bracket to mount the new Valve in the old spot. Had to get a couple of different adapters to go from the factory Yota brake lines into the Valve but they dont cost much. anyway, worth a shot. Worked perfect for me.

 

[roscoFJ73]

I cant see how the proportioning valve would make a difference to the front brakes.

When the proportioning valve isnt working properly it affects the rear brakes only as the front brakes have their own separate brake lines to the master cyl.

 

[amaurer]

Well I think the big issue is that one tends not to keep pressing harder on the pedal once you hear the rears let go, which means the fronts appear not to work as well.

I adjusted the LSPV linkage 1" shorter and now she stops like a champ, no lockup. Squishy pedal is mostly gone, or at least when it shows up its much much better.

Is it possible that my shackles are too tight (I also never greased them) and the ride height is getting stuck +/- an inch or so? Several times now in the parking lot I've thought the rear of the truck looked high, only to see it back to normal the next time I parked...

 

[Camperboy Belgium]

At this moment i'f got a similar problem.
New pads, new pumps, sanded everything and stil a difference in breaking power, more than 25% between left and right.
My guess, dirt in the brake lines. Bleed them under pression, change brake fluid...