I've been looking for a project

[z8987]

Brakes.  New booster, in place with master cylinder.  All new calipers, brakes everything new with the exception of the old hard lines.  The old hard lines were blown out and cleaned of all fluid before installing all the new products.   I spoke with Steve at Power Brake Booster Exchange about my booster.  According to him my booster needs no further adjustments.  We bled the lines today, but the pedal still goes almost all the way to the floor.  Here's what I've done.

- I capped the master cylinder and the brake pedal is hard to push on and will not go to the floor - so my guess is that the booster and master cylinder are good.

- connected front brakes to master cylinder, brake feels good, 

- connected back brakes, we bled the brakes, a solid flow of fluids but the brake will now go almost all the way to the floor.

 

Any tricks?   One person suggested I open the bleeders and let gravity assist in getting fluids through the system.  Sound reasonable, but we have a steady flow at both back brakes.   errrrr.. 

[Zed Head]

Do you have the stock drums on the back?  Sounds like you need to adjust them.  The shoes are too far from the drums.  Take the drums off and turn the adjusting wheel that moves the shoes apart  until you can barely get each drum back on.  Then pull the parking brake handle up and down a few times to get the final automatic adjustment.

[z8987]

2 hours ago, Zed Head said:

Do you have the stock drums on the back?  Sounds like you need to adjust them.  The shoes are too far from the drums.  Take the drums off and turn the adjusting wheel that moves the shoes apart  until you can barely get each drum back on.  Then pull the parking brake handle up and down a few times to get the final automatic adjustment.

Did that! 

[Zed Head]

9 minutes ago, z8987 said:

Did that! 

!

[grannyknot]

And the rubber flex lines are new and not bulging out when you press the brake?

[z8987]

2 hours ago, grannyknot said:

And the rubber flex lines are new and not bulging out when you press the brake?

Yes, new rubber hoses. My guess is they are not bulging.  That's something I can check, but since they are new, they should be in good shape. 

[Patcon]

Block off the front brakes and see what you get. It has to be one of just a few things:

Air, a leak, bulging line, too much slack

My bet is on air if you've got the adjustment right. The lines are long and I have run almost a whole quart through to get all the air out

Do the rear drums have any lip on the inside edge?

[z8987]

17 minutes ago, Patcon said:

 

Do the rear drums have any lip on the inside edge?

I'm going back to blocking off the front as suggested, and I'll check on the lip. I don't think there is one, but I'll look. I'll be out shooting all day. This retirement is wearing me out. ?

 

[Persimmon240]

I may be out of "line" here - but give me a "brake". I realize you indicated that your fronts had good pedal; but you also indicated that you replaced the calipers. Are the bleeders pointing up? The reason I ask is because - back in my misspent youth, I happen to have removed and then re-hung the calipers on the wrong sides. I am sure stocks in brake fluid went up during the days it took to solve my recalcitrant retardation. Worst case it is one more thing you can cross off of the list. Besides, who told you retirement was relaxing?

[Zed Head]

17 hours ago, z8987 said:

- I capped the master cylinder and the brake pedal is hard to push on and will not go to the floor - so my guess is that the booster and master cylinder are good.

- connected front brakes to master cylinder, brake feels good, 

- connected back brakes, we bled the brakes, a solid flow of fluids but the brake will now go almost all the way to the floor.

The testing seems to show that the problem is in the back.  If z89 keeps "doing things" he'll probably find the problem.  Use the same logic that was used to isolate it to the back end.  There are similar tricks that he could do if he thinks about the pistons in the wheel cylinders.

[grannyknot]

This might be a bit out there but if the cause isn't found soon it might be worth a look,  I disassemble all new hydraulic parts I purchase because I have found more than a few things wrong over the years, muck, grease, rust, sometimes the seals are installed backward or springs missing. I hope you don't have to go that far.

[z8987]

10 hours ago, Persimmon240 said:

I may be out of "line" here - but give me a "brake". I realize you indicated that your fronts had good pedal; but you also indicated that you replaced the calipers. Are the bleeders pointing up? The reason I ask is because - back in my misspent youth, I happen to have removed and then re-hung the calipers on the wrong sides. I am sure stocks in brake fluid went up during the days it took to solve my recalcitrant retardation. Worst case it is one more thing you can cross off of the list. Besides, who told you retirement was relaxing?

Checked that. sounds like you were not the first to do that