Rear drum brakes issue

Just replaced the rear brake shoes and had the drums machined. I think I may have done something wrong, though. Went for a test drive..... When I step on the brake pedal I feel the brakes grab but then it feels like it releases a little then the pedal travels lower and the brakes grab again. It feels like the pedal is almost to the floor when I stop. I used the repair manual and went step by step. I'm confident I got it all together the right way.

What could I have done wrong?

Thanks

 

Did you use the star wheel to adjust them after you put the drum on?
Did you bleed them? You may have air in the lines, if you did.

 

This.

Sounds like you need to adjust the drums and bleed the brakes.

 

X3 I'm gonna go ahead and assume you adjusted them. I'm guessing they need bled.

If you didn't adjust them, then adjust them till there is just a slight sprag. But soft pedal suggests air in the line.

 

Actually, he never used the word soft, though there might be air. Pedal to the floor I'm thinking means he didn't adjust the shoes, and the pistons are having to move way to far to have shoes engage in a loving way with the drum, especially since he turned them, so that they are larger than before.

 

make sure that you don't put the little auto adjusting bar (thing with the star wheelie thinger) on backwards... I did that. The didn't really work right.

 

I hate drum brakes just for that "self adjuster parts".. But sounds like you need to purge some air out of your line, do the "8 & hold" (pump pedal 8 times & hold firm till you or your buddy cracks the bleeder zerk, repeat as neccessary)

 

Make sure you are filling master cylinder as you bleed the brakes. If you aren't losing any fluid as you bleed them, you aren't there yet for sure.Like stated when you bleed them you pump brake allowing pedal to come back in between each pump. When to 6 or 8 hold pedal to floor and have friend open with wrench and close before releasing pedal. Repeat,Repeat and so on. Check fluid level as you go. Takes quite a few times somrtimes. GL

 

Thanks for the replies.... Apparently I did not read the rest of the steps in the repair manual..... Specifically where it says how to adjust the brakes after replacing them. After reading your replies I realized I must have missed that whole part. Just like you all said, it explains how to adjust the star wheel and how to drive in reverse making repeated stops to activate the self-adjusting mechanisms. I did all that and they feel so much better or 'normal'. I did not try to bleed them yet but I'll see how it goes from here and do that if necessary.

Again, thanks for the replies.

 

There should be no need to bleed the system, if all you did was replace the shoes and drums. Did you, for some reason, disconnect a hydraulic line while doing the work?

 

i did not disconnect any lines. but i went ahead and did the bleed procedure, anyway. it did not make a difference. i'm still having the same issue... once in a while the pedal goes way down when stopping or slowing down. the fluid level is good.
what could be causing this?

 

I would run through the adjustment procedure again first, and redo the bleed second. And make sure you aren't leaking any fluid from the wheel cylinders.

Beyond that, either something is assembled incorrectly, or you could have a bad master cylinder or brake booster. But typically those would make it happen all the time or at least a lot more often. Make sure there is not a vacuum leak in the brake booster hose.

 

Just going in reverse will take a year to make them self adjust. You have to have them close first.

After that if you're still having issues, spend the $50 at the brake shop.

 

Not really. When we replace the brakes here I just get the base install set and it takes about 5 or 6 reverse runs and I get them perfectly adjusted.

 

These trucks have the most finicky drum adjustment I've ever seen. They work good when right but when out of adjustment they make the pedal super soft. I'm not sure what the repair manual says but I just adjust until I get some resistance spinning the tire and back off a click or so. It doesn't take much out of adjustment to get a soft pedal.

 

This doesn't make sense to me.

On my '99, the auto-adjust mechanism is connected to the e-brake. With the drum off, manually working that lever behind the backing plate moves the adjusting wheel. It doesn't look like backing up would do that.

Howerver, I do seem to recall that, with my old Plymouth (from the 70's), backing up did adjust the rear brakes.