Brake pedal goes to the floor after new shoes

I am having the same problem

1996 c1500.
Did all new front and rear brakes.

I thought my caliper was locked up..
turns out, my drivers side wheel bearing exploded.



Anywho,
I sanded the spindle a bit, put new timken bearings, followed by new rotors calipers pads and rubber lines.

All new 10” drums plus cylinders in the back as well.

HOW DO YOU PROPERLY ADJUST THESE DRUMS??

there’s no access hole in the backing plate for adjustment, only visual inspection.

Despite the service manual saying I need to adjust them from the back with the wheel on

Are they just self adjusting via parking brake/ reverse?
Is there a best practice to doing this?


Next problem:
When bleeding the very first drum RR
I let the master reservoir run out of fluid.

I then bled all 4 brakes about 15 times each via gravity and a stick to hold in the brake pedal.

Was getting all fluid. No air.

However, as soon as I start the truck,
Brake pedal is squishier than a pound cake.
It brakes, but it seems REALLY soft.
Way too much travel before braking really kicks in effectively.


Is my best bet at this point to assume I let air get in the master/
The ABS
The lines

And can I take this to my mechanic for a simple brake fluid flush now?
To finish up this ordeal of a job

Isaacmacleod said:

I am having the same problem

1996 c1500.
Did all new front and rear brakes.

I thought my caliper was locked up..
turns out, my drivers side wheel bearing exploded.

You must be registered for see images attach

You must be registered for see images attach

Anywho,
I sanded the spindle a bit, put new timken bearings, followed by new rotors calipers pads and rubber lines.

All new 10” drums plus cylinders in the back as well.

HOW DO YOU PROPERLY ADJUST THESE DRUMS??

there’s no access hole in the backing plate for adjustment, only visual inspection.

Despite the service manual saying I need to adjust them from the back with the wheel on

Are they just self adjusting via parking brake/ reverse?
Is there a best practice to doing this?


Next problem:
When bleeding the very first drum RR
I let the master reservoir run out of fluid.

I then bled all 4 brakes about 15 times each via gravity and a stick to hold in the brake pedal.

Was getting all fluid. No air.

However, as soon as I start the truck,
Brake pedal is squishier than a pound cake.
It brakes, but it seems REALLY soft.
Way too much travel before braking really kicks in effectively.


Is my best bet at this point to assume I let air get in the master/
The ABS
The lines

And can I take this to my mechanic for a simple brake fluid flush now?
To finish up this ordeal of a job

Click to expand...

Generally best to start a new thread rather than drag up an old one.

Is the pedal firm just a lot of travel or squishy even after taking up the travel? With the rear drums out of adjustment, pedal travel will increase as the wheel cylinders require greater travel to press the shoes against the drum.

Once you get the shoes adjusted out where they need to be, pedal travel should decrease. To adjust the shoes without the access hole, do a test fit by spinning the adjuster out, slid drum on, pull drum, adjust, repeat. While drum is on each time, apply the brakes (service or parking) and release to center the shoes. Is there a knockout in the backing plate that lines up with the adjuster?

There's also the possibility that you've gotten air trapped in the ABS that needs bled out. Seems to be some challenges to doing this that may require a bidirectional scan tool to chatter the valves or run an auto-bleed. There's a thread on here somewhere about which scan tools are known to work with which ABS system.

More knowledgeable folks will likely chime in as well.

Isaacmacleod said:

1996 c1500

Click to expand...

Isaacmacleod said:

Did all new front and rear brakes.

I thought my caliper was locked up..
turns out, my drivers side wheel bearing exploded.

Click to expand...

Folks used to pack the wheel bearings with fresh grease every brake job at minimum, every year for folks who really cared. I just loved repacking bearings...easy work, paid OK, no real headaches involved unless it was a 4WD because the third inside bearing was a bugger.

But so many cars have sealed-for-life wheel bearings that the bearing service has fallen off of folk's radar.

Isaacmacleod said:

I sanded the spindle a bit, put new timken bearings, followed by new rotors calipers pads and rubber lines.

Click to expand...

New seals, new cotter pins, and a bunch of NLGI #2 GC or GC/LB grease in the rotor/hub, plus pushed through the gap between the bearing rollers...right?

Isaacmacleod said:

All new 10” drums plus cylinders in the back as well.

HOW DO YOU PROPERLY ADJUST THESE DRUMS??

Click to expand...

Yeah, they're a pain in the asp. I used to just yank the drum off, tighten the adjuster star-wheel, and slide the drum back on for a test-fitting. When the adjustment got close, I'd have to step on the brakes WITH THE DRUM ON to expand the shoes via the wheel cylinder--which aligns and centers the shoes. Then probably tighten the star wheel again once or twice. Drum on...drum off. Drum on...drum off.

Isaacmacleod said:

Are they just self adjusting via parking brake/ reverse?
Is there a best practice to doing this?

Click to expand...

The 254mm (10") leading-trailing shoe drum adjust the first time you step on the brake pedal AFTER releasing the park brake. So you HAVE to use the park brake regularly and frequently, or the shoes go out-of-adjustment.

But you'd go insane trying to adjust a fresh brake job with the park brake/release park brake/step on the brake pedal procedure. Spin the star wheel by hand or with a brake spoon.

Isaacmacleod said:

When bleeding the very first drum RR
I let the master reservoir run out of fluid.

Click to expand...

You'll have to bench-bleed the master. You could try lifting the rear of the truck as high as you can, so that the front of the master cylinder is tipped DOWN. Then tickle the brake pedal and maybe the air in the cylinder will get pushed up into the reservoir. OR you unbolt the master from the booster WITHOUT removing the brake tubes. Force the front of the master cylinder DOWN in front. Then tickle the primary piston with a Phillips screwdriver, or wood dowel, or whatever you can get in there to push the piston.

Isaacmacleod said:

as soon as I start the truck,
Brake pedal is squishier than a pound cake.
Is my best bet at this point to assume I let air get in the master/
The ABS
The lines

Click to expand...

It's certainly got air in the master cylinder, which you can bleed out with the above procedures that tip the master cylinder down in front.

MAYBE you got air in the ABS, or the plumbing to the wheels...probably not since you've bled that several times.

Good luck.

Isaacmacleod said:

And can I take this to my mechanic for a simple brake fluid flush now?

Click to expand...

Sure. ASK THEM if they have the proper scan tool to auto-bleed the ABS.

And they're still going to need to bleed the master cylinder, either on the car or off the car.

This is going to cost...

termite said:

Generally best to start a new thread rather than drag up an old one.

Is the pedal firm just a lot of travel or squishy even after taking up the travel? With the rear drums out of adjustment, pedal travel will increase as the wheel cylinders require greater travel to press the shoes against the drum.

Once you get the shoes adjusted out where they need to be, pedal travel should decrease. To adjust the shoes without the access hole, do a test fit by spinning the adjuster out, slid drum on, pull drum, adjust, repeat. While drum is on each time, apply the brakes (service or parking) and release to center the shoes. Is there a knockout in the backing plate that lines up with the adjuster?

There's also the possibility that you've gotten air trapped in the ABS that needs bled out. Seems to be some challenges to doing this that may require a bidirectional scan tool to chatter the valves or run an auto-bleed. There's a thread on here somewhere about which scan tools are known to work with which ABS system.

More knowledgeable folks will likely chime in as well.

Click to expand...

Thanks for the quick reply!
Good to know,
I’ll make a new thread next time.
This thread seemed very similar to my current issue, however.

There is no knockout for the star adjuster on these 10” drums.

Only two oval shaped knockouts that allow you to view the point of contact between the drum and the shoes.
I guess that could help potentially with adjusting.

My brake pedal goes very easily down to almost the floor, then gets stiff and comes to a complete stop at the bottom.

If I press the pedal in half way, the stopping is very minimal but noticeable.

Schurkey said:

New seals, new cotter pins, and a bunch of NLGI #2 GC or GC/LB grease in the rotor/hub, plus pushed through the gap between the bearing rollers...right?

Click to expand...

Yes sir

Schurkey said:

The 254mm (10") leading-trailing shoe drum adjust the first time you step on the brake pedal AFTER releasing the park brake. So you HAVE to use the park brake regularly and frequently, or the shoes go out-of-adjustment.

But you'd go insane trying to adjust a fresh brake job with the park brake/release park brake/step on the brake pedal procedure. Spin the star wheel by hand or with a brake spoon.

Click to expand...

Understood,

So the goal is to get the shoes as close as possible to the drum while Still being able to slide the drum back over the top?

Then finish off with some e-brake then regular brake.

Schurkey said:

Sure. ASK THEM if they have the proper scan tool to auto-bleed the ABS.

And they're still going to need to bleed the master cylinder, either on the car or off the car.

This is going to cost...

Click to expand...

Well I really wanted to save some money by doing this all myself but I guess it’s time to turn over the reigns.

doing that is definitely above my current level of ability.

I was really hoping for the 130$ brake flush to take care of everything.

Any estimate as to how much it might be now?

Isaacmacleod said:

Thanks for the quick reply!
Good to know,
I’ll make a new thread next time.
This thread seemed very similar to my current issue, however.

There is no knockout for the star adjuster on these 10” drums.

Only two oval shaped knockouts that allow you to view the point of contact between the drum and the shoes.
I guess that could help potentially with adjusting.

My brake pedal goes very easily down to almost the floor, then gets stiff and comes to a complete stop at the bottom.

If I press the pedal in half way, the stopping is very minimal but noticeable.

Click to expand...

One of these more knowledgeable folks, Schurkey, has commented. Follow his advice and good luck getting it worked out.

Schurkey said:

Folks used to pack the wheel bearings with fresh grease every brake job at minimum, every year for folks who really cared.

Click to expand...

I have been wanting to repack my bearings since I got the truck. Everyone told me to wait till I did the brakes.
Ended up blowing a wheel bearing.
Sigh

termite said:

One of these more knowledgeable folks, Schurkey, has commented. Follow his advice and good luck getting it worked out.

Click to expand...

termite said:

One of these more knowledgeable folks, Schurkey, has commented. Follow his advice and good luck getting it worked out.

Click to expand...

Thanks you guys

Isaacmacleod said:

I have been wanting to repack my bearings since I got the truck. Everyone told me to wait till I did the brakes.
Ended up blowing a wheel bearing.
Sigh


Thanks you guys

Click to expand...

I would like to add since i never posted a final update I got my brakes feeling good as new. I never posted because i felt like a complete idiot when i found the problem. To anybody who comes across this thread in the future, remember to adjust the drums with the PARKING BRAKE OFF!