Weak Brakes - Need Help Diagnosing

[75sv1]

My take. The previous job looks hacked. The routing of the rear lines, is suspect. Makes about anything less, questionable. Yeah, I'd put new calipers on the front. I went through this with my Chevy Avalanche last year. Looked like recent parts. I found chunks in the Master Cylinder. I botched a new one. I didn't bench bleed it right. I also had a '78 Civic. Had the brakes replaced a few times. The rotor on those were pressed between the bearing. They didn't bleed the front calipers. When I did, there was a rust blob that came out. Yeah, new calipers. 

[dotnetrob]

Finally have an update. Broken and rusted shut bleeders, 1 rotor was in bad shape, rusted onto the wheel bearing and corners of the rotor was all beat up. Rusted on dust covers, or what was left of them.  1 of the pads on the passenger side was partially broken, 1/4 of the pad was missing.  The driver side drive shaft nut would not come off, so removed the drive shaft with wheel bearing all in one piece.  With all the carnage, everything needed to be replaced.   

1. Cleaned and painted knuckles
2. Replaced the drive side drive shaft.
3. new axles nuts and caps on both sides  
4. Installed 2 new wheel bearings. 
5. Installed 2 new dust shields. 
6. Installed 2 new rotors.  
7. Installed 2 new calipers
8. Installed new brake pads on both sides.

All installed and front brakes bleed.

 

Was going to do a CAD delete while I was at it but need to stay on task for now and get the brakes working.

 

After taking a quick test drive, there is an improvement.  Not huge, but noticeable.  Would say before I replaced all the front brakes, braking power was maybe 20%, would say its maybe 30% now.  Still horribly weak, but does stop better.   

 

On 8/6/2025 at 8:12 PM, coolwind57 said:

Page 5 of one of my write-ups shows what I did to delete a few things.  Something for you to have a look at.  Might get you some ideas.  Good luck, friend.  It's about half way down page 5:  

 

After looking at @coolwind57 write up.  I believe I am going to add a proportioning value up front near the master cylinder for the rear brakes and convert the rear brakes to 1 line to the rear.  Anyone see any issues with this idea?  Attached a horribly drawn diagram of the current and proposed setup.

 

 

 

 

 

[coolwind57]

I've not looked back.  No issues since I did my mod.  

[ghetdjc320]

Keep in mind also that the pads you select will play a big roll in braking. Centric posi-quiet is a good setup as they are softer and grab better than most. And make sure to follow break in procedures with new pads and rotors. The braking difference is substantial. Good break pads will create a bit of break dust but that what you want with an otherwise stock braking system. 

[ratrapp]

exactly.i ve told alot of my customers that complain about brake dust.i try to explain to them the dust is a byproduct of the pads actually working.i know some may leave more residue than others but if they are too clean that means theyre not doing much.

[75sv1]

6 hours ago, ghetdjc320 said:

Keep in mind also that the pads you select will play a big roll in braking. Centric posi-quiet is a good setup as they are softer and grab better than most. And make sure to follow break in procedures with new pads and rotors. The braking difference is substantial. Good break pads will create a bit of break dust but that what you want with an otherwise stock braking system. 

I was going to post something similar. I used mid grade NAPA pads on my Avalanche. They really didn't bite or brake well. I am having rims redone. $$$. So, it was suggested to use Ceramic pads. I went with Aldios pads. Supplier to Toyota. I like how they brake. From post on the net, Centric and Wagner Thermo quiets get good reviews. I do have the NAPA/Wagner or is it Raybestos Reactive pads and rotors. They are OK. I plan to change the fronts to Black Magic pads at some point.

[dotnetrob]

8 hours ago, ghetdjc320 said:

Keep in mind also that the pads you select will play a big roll in braking. Centric posi-quiet is a good setup as they are softer and grab better than most. And make sure to follow break in procedures with new pads and rotors. The braking difference is substantial. Good break pads will create a bit of break dust but that what you want with an otherwise stock braking system. 

 

These Napa pads are the pads I ended up with.   Hopefully they work well.  If there are pads anyone recommends please add a link.  

 

Working on getting the brake lines and fittings I need to do the plumbing changes.  Already own the line bending tools and flaring tools, just need the fittings and line.