Brake Question

[Eagle]

The rear adjusters were likely your problem. The rear drums should be adjusted just to the point of VERY light contact when rotating the wheel when the brakes are not applied, then back off like one click.

 

The self-adjusters generally don't self-adjust, so you should check the adjustment every six months or so -- or more often if it's a daily driver.

[Dadinator]

All reassembled yesterday, and the brakes are still just as crappy as before.  :wall:  New master cylinder, new wheel cylinders, new fluid flushed through the lines, bled the lines to the point where new fluid was coming out of all 4, adjusted the rears as stated above. Took the wife's TJ out for a quick spin and can lock them up easily.

 WTF? :headpop:

[cruiser54]

Ever read this all the way at the end?

 

http://www.autoshop101.com/forms/brake05.pdf

[Dadinator]

I just did.

I am not sure it helped.

The booster seems to be working fine.

:dunno:

 

Why would the push rod need adjustment?  If it is that, would it not go all the way to the floor?  I don't think it does.

I will have to look.

 

Maybe I am just stupid...

:yes:

[cruiser54]

I just did.

I am not sure it helped.

The booster seems to be working fine.

:dunno:

 

Why would the push rod need adjustment?  If it is that, would it not go all the way to the floor?  I don't think it does.

I will have to look.

 

Maybe I am just stupid...

:yes:

Because in the mixing and matching of masters and boosters they don't always match. And no, it wouldn't go all the way to the floor but would be slow in applying. 

[Dadinator]

The original master cylinder and booster were stock.  The truck has been in the family since new.

The brakes have not worked well for years.  Not sure when they started becoming weak, because the son had the truck for years and didn't pay too much attention to it.

 

I have had it for about 3 years now and the darn brakes have never been right.

 

I just started messing with it because I changed out the front axle and it seemed they were worse.  But after doing what I have so far, it is back to just plain crappy like it was when I took it over.

 

 

It doesn't seem to be slow in applying, just weak.  The booster seems fine.  When starting the truck with brake pressed, you can feel it just like a normal vehicle.

Maybe something needs adjusted in there. 

 

Is there anything else I am missing? 

 

What about the proportioning valves? 

 

Where's my 12 gauge?

[Eagle]

What about the proportioning valves?

There is only one proportioning valve, and that's a distinct possibility.

 

When you worked on the brakes, did you follow the MJ-specific procedure for bleeding, to ensure that the rear brake bypass line doesn't have air trapped in it?

[Dadinator]

No, I guess I did not.  I'll have to look that up and see.  Just bled like a normal vehicle.

Hopefully, I will have time to do that later this week or weekend. 

[Eagle]

No, I guess I did not.  I'll have to look that up and see.  Just bled like a normal vehicle.

Hopefully, I will have time to do that later this week or weekend.

http://comancheclub.com/topic/4647-brake-bleeding/

 

http://comancheclub.com/topic/27326-brake-bleeding-procedure-with-rear-height-sensoring-valve/

[carnuck]

When you lifted the rear, did you extend the load level arm rod to match? If not, try undoing the rod and pushing the arm up then try driving it (zip lock the arm up) I bypassed mine a long time ago.

[Dadinator]

carnuck,

Tried that already.  No change.

[carnuck]

Are the pads quality ones? If not, they may be glazed. The ceramics I have on mine need a few stops to get warmed up in the morning before it stops really good and that's with the late model XJ booster/master and pedal swap.