issues with rear drum brakes. STILL

[of13swc]

Ok I have replaced drums, pads and cylinders, and have bled.. But rear brakes still not working. Not sure what to do next. The only thing is the previous owner removed the parking brake every part of it to include the strut in side drum, would this have anything to do with my issue? I have read the flex line could have collapsed. PLEASE help.

[Sharps40]

Nope, removeing the parking brake wouldn't cause a completely rebuilt system to fail. My guess is if you replace the cylinders you still have air in the lines or got some gunk in one of the ends and its plugged or slow or you have reassembled components and caused a bind. Last item, starwheel and lower spring, did you pull the shoes out to slight drag on the drum both before and after bleeding? If not, you can have an air free hydrolic system and get no contact between shoe and drum.

Don't know what you mean by "still not working"...cylinders stuck? drum stuck? No shoe contact, etc.

Pics would be a big help evaluating the mechanicals. Only way to evaluate the hydrolic is to ask if yer brake is spongy or firm in top of the stroke...or does it fall to the floor, etc.

A lot more detail is needed to help you out.

[jocko]

alright, dumb question - but, did you adjust out the shoes to almost make contact? (i.e. via the star adjuster wheel - if your drum slipped on too easily, then you may not be making contact). I'm sure you probably did this, just wanted to ask though.

concur with Sharps - removed pbrake hardware shouldn't affect normal brakes.

[of13swc]

The drums were very easy to get on. I can stand on the brake and rear wheels spin free like there was no pressure on the brake pedal. I have went back and adjusted the star wheel and now more difficult to get on. My pedal does not fall to the floor but is soft. I went to bled the brakes again and now cant seem to get the rear to bleed. Its like I have lost pressure.

[78f1hundo]

Sounds like you have air in the lines.... Look up gravity bleed, it has worked for me. You crack the bleeders over night and the air rises and the system bleeds itself.

[Sharps40]

You have air in the lines. You prolly also need finer adjustment on the shoes, but that comes after proper bleeding.

Not to be rude but do you have a comprehensive assembly and adjutment manual for the brakes. If not I'd suggest reviewing both Motors and Haynes.

Possible methods:

1. Bleed it further by pumping, bleed all four wheels to be sure. Pumping works but can be super slow and need lots of repeats to get all the air.

2. You can also try cracking one cyl at a time for gravety assist, but its also slow (it was the only way I could bleed all four when I did the Dual Pot Swap.) and needs pumping to finish the job.

3. Rent a mighty vac and pull the fluid down to the cylinders.

4. Modify a garden pump up sprayer and push the fluid thru the master to the cylinders.

Any spongeyness at all and the job has got air in it. (You can get it rock hard by the traditional pumping methods, come back in the morning and its spongy cause the air bubbles break up in a froth and then recombine some overnight.)

Just keep tryin...and remember, when finally blead, adjust the shoes for light drag on the drum....about 1/2 to 1 spin of the wheel with the tire on.

[61_FL_Apache]

If you have a single line coming from the MC, try bleeding all 4 wheels. If you were able to bleed the rears before, the rubber line should be good. However, if it has started to collapse which has happened to me on some front brakes in the past, the rubber line may have caught some trash and now you have no fluid passing thru.. Its only one line in the rear, I would replace it if you have any doubts.

[of13swc]

OK well I found the front right brake caliper bleeder screw was leaking. The bleeder was replaced but I could not tighten it enough to stop leading from the bleeder. New calipers are 20 bucks so I am off to the parts store. I am also replacing the flex line in the rear just to eliminate that possible issue. I have tightened the star screw on the adjuster again. Now when I tighten bolts for the spacers (because it has after market wheels and the new ones will not fit over the front hub) its VERY difficult to turn wheels. So frustrated with this!!!! Will bleed AGAIN once everything is on again. Could it also be the master cylinder?

[of13swc]

Rear drum with new brakes, springs and star adjuster.

[notsolo]

Some of this can be very frustrating, 50 years and lots of people messing with it. Here is a check list...also Markeb01 has some great tips and some other input may help you get your truck brakes set correctly.... 67-72chevytrucks.com/vboard/showthread.php?t=477353

[61_FL_Apache]

Look at the bright side... You would have flushed ALL the old fluid out of the system... at least twice!

On a side note, did you have your axles re-drilled to fit 5 lug?

[of13swc]

The previous owner did.
QUOTE=61_FL_Apache;6023842]Look at the bright side... You would have flushed ALL the old fluid out of the system... at least twice!

On a side note, did you have your axles re-drilled to fit 5 lug?[/QUOTE]
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[61_FL_Apache]

Ok.

[AcampoDave]

When a friend of mine had a similar problem it was because the push rod was not completely releasing the piston in the master cylinder when the pedal was in a fully rested position. After making sure the rod had a tiny bit of free play, all went well. Best of luck

[of13swc]

Thanks. I have a new master cylinder coming.

Originally Posted by AcampoDave

When a friend of mine had a similar problem it was because the push rod was not completely releasing the piston in the master cylinder when the pedal was in a fully rested position. After making sure the rod had a tiny bit of free play, all went well. Best of luck

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[64GMCHorsepower]

Originally Posted by of13swc

Thanks. I have a new master cylinder coming.


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Don't forget to bench bleed the master cylinder.......Makes the whole process easier!

[of13swc]

What's the easiest way to do that?

Originally Posted by 64GMCHorsepower

Don't forget to bench bleed the master cylinder.......Makes the whole process easier!

[of13swc]

Again thanks to everyone who has helped we with this process. I assume its because we are Chevy guys.. HEHEHE

[Lugnutz65]

Originally Posted by of13swc

The drums were very easy to get on. I can stand on the brake and rear wheels spin free like there was no pressure on the brake pedal. I have went back and adjusted the star wheel and now more difficult to get on. My pedal does not fall to the floor but is soft. I went to bled the brakes again and now cant seem to get the rear to bleed. Its like I have lost pressure.

On the subject of adjusting the star wheel - here's a tip. I discovered this method by accident and it's so easy to do, that I put it on my BLOG in the Tips and Tricks section.

How do I adjust the brakes? See below. I did a cut and paste from my BLOG.

This idea might be easier than the method you currently use.
When it comes time to adjust the brakes, this is what worked for me. This method is very simple and eliminates the need for special tools to measure the brake drum diameter or adjust the star wheel through the hole in the backing plate. It works for drum brakes, front or rear.

First, perform the needed repair or replacement of the drum brake system, be it a rebuild or just new shoes.

After installing new brake shoes, it is always necessary to adjust the shoes to obtain the proper friction inside the drum.

This example is for the rear drums, but the front drum adjustment procedure is about the same.

Step 1. If the drum has a little friction from the brake shoes when you slide it on, that's good! So, before bolting the wheels on, try to adjust the star wheel so there is at least a little friction, but not too much. Do the same for both rear wheels.

Step 2. Mount your rear wheels.

Step 3. Chock the front wheels. Put a jack under the differential and lift the rear axle up enough so BOTH rear tires are off the ground. Have a helper REPEATEDLY press and release the brake pedal WHILE you spin the rear tire in REVERSE. You should hear and maybe even feel the star wheel adjusting the brake shoes to the correct tension. Do this on the other side. Repeat the process UNTIL YOU CAN NO LONGER TURN THE TIRE BY HAND while the brakes are on. Always check your newly installed/adjusted brakes in a safe area in case of unexpected failure.

Why does this work? Well, the star wheel is a design feature that SELF ADJUSTS the brake shoes - but it is only activated by applying the brakes while driving the truck in reverse. We all back up our vehicles several times per day, so the mechanism will keep the brakes properly adjusted as long as they are properly maintained.

[64GMCHorsepower]

Originally Posted by of13swc

What's the easiest way to do that?

Clamp the M/C in a vise, then you run tubing from the ports of the MC back into the reservoir.

Fill it with fluid, and using a screwdriver or a rod of some sort, keep pushing the piston until you get no air bubbles showing up in the reservoir.

When I bought my new one, it actually came with the fittings to do this.

And you might look at buying a set of autobleeders. They work great for the one time you need to bleed your brakelines, especially if you don't have any help. Most parts places carry them.

Good Luck!