my breaks are giving me fits.... i blead and blead-no luck, put in  a new master cylinder (bench bled twice) and when i blead the breaks all seems well.  then when i run it i barley have anything!  i shut it off and let it sit, pump them and they come back and stay..... really lost here,  HELP!  and i did put on new pads and shoes too....

is this a break booster problem?   anyone ever rebuild a booster?  the shop manual makes them look pretty complex......

you need to adjust the rear shoes,
then the pedal will feel right.

Wild

A booster problem is usually noted by good firm pedal hard to push but still doesn't slow you down like normal.  Sounds like you are experiencing an issue with the master cyl, proportioning valve, or line fitting.  

Why did you originally begin you brake work?  

Are you loosing any fluid?

Are you getting good fluid flow from all of the bleeders?

Have you tried bleeding the brakes with the truck running (brake booster powered)?

On Samurai's somtimes I've had to nose them in a ditch to bring the rear brake line and proportioning valve section higher to get all of the air out.

If the mastercylinder was a reman unit a defect is not out of the realm of possability...

Keep us posted.                            MW

thanks for getting back to me on this.  started doing this all because of the problem i am still having.  so since problem is still the exact same.  i doubt it is a bad master cylinder, but ya never know.

never lost/loosing fluid
getting fluid from all bleeders(and breaks feel great after till i start the motor)
i heard that you are NEVER to bleed breaks with the car running cause the added power will turn the fluid into i high presure danger.

you need to adjust the rear shoes

what do you mean "adjust"?

dont have a ditch but i can start looking for one.  i have also tried using a break bleeder pump, seemed like the ol' pump and hold worked better.....

UGGGG i hate this, i just got my new motor with all my up grades in and i cant drive it!
thanks again.........will check back later

what do you mean "adjust"?

The drum brakes have 'turnbuckle' type adjusters on them that pre-load the brake shoes closer to the drum. There are slots in the backing plate where you would put in a flat blade screwdriver and spin the 'turnbuckle' until the shoes start to drag on the drum. You want drag on the drums so that it when you spin the drum by hand it turns about 1/2 to 3/4 a turn [this is subjective ]



With properly adjusted drums the pedal will be firm and at the top assuming nothing else is wrong with the rig. A quicky way to test if the rear is out of adjustment is to pull the e-brake just until there is a little drag and let off a click. Now hit your brakes. Did the brakes feel better? If so, your rear shoes need adjusted.





Good luck, Eric

thanks eric, off to try this now, would this expain the running non running difference?  will let you know.

update

well the rear are adjusted correct.  i read in the service manual how to check the booster, its ok.  i have bled 4 times now and they are getting better.  the last time i just did the rear ones.  got some air out of the left rear and none out of the other.  this seemed to help alot. i think i am just going to bleed them every other day for 2 weeks and see what happens.  still not ditch but i still think that might also be a good idea.

thanks again all

Are you bleeding them in the "proper order"? If not, you will leave some air in the line. Also make sure that you dont let the fluid level get low when your bleeding (and risk more iar getting in).
Zig

Are you bleeding them in the "proper order"? If not, you will leave some air in the line

thanks for the Q, and yes i am.  rear left, rear right, then front...... well i look at the service manual every time to make sure.  ya know though that order doesnt make sence to me, seems like you would want to first bleed the RR, if you do the LR real good where could you have air in the RR?  it leads to the LR.  but i do it like it says anyway.  i am very afraid that i am going to have to take it to a break place.  man, i hate it when i cant fix something myself.  and its ganna be something dumb, which will piss me SOOO off

I was thinking it was just the opposite :-/ Bleeding closest to the master cylinder first and ending up furthest away. That way you push all of the air past each point in the line and then move to the next :-/ I cant remember, it's been a while since I bled my brakes. I'll try to get some info with a Brake Bleeding thread.
Zig