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Update: Problem Solved - Seized/Locked Brake Issues

8

808Avee

Full Member
Joined
May 13, 2020
Messages
10
2005 Avalanche 1500 z71 4x4

Advice/Recommendations appreciated

Daily driving note: Never used the 4x4 mode, only kept in 2WD (No off roading adventures - I know how boring :)

*Rear brakes locking on slow start and turns, then releases as rpm increases in straightaway
*Approaching highway entry feels like back wheels are locking and tire screech is heard
*Slight undercarriage vibrations are felt during turns and slow stop
*Removed ABS fuse in hopes of driving until issue is resolved - problem still present

Backstory...

Did a home repair on my dash cluster (PRNDL) as the readouts with the gears and mileage displays were dim to none.
Resoldered the resistors which were faulty and problem solved...BUT a new one evolved.
Here's the notable events when removing the cluster.
*Avy in park position ignition off
*Gears lowered in accessory mode and vehicle off to remove cluster (flat ground garage kept)
*Avy begins to roll forward, pressed foot brakes and engaged parking brakes (left foot) - it was then while doing this action I felt a hard pump back from the foot brakes. Thought nothing of it then but it could be a focal point of where I need to look.

Could the rear disc brakes assembly need to be replaced?
Just seeking inputs of plan of approach.

Mahalo!

Aug//Sept 2021
*Master cylinder replaced
*Brake reservoir replaced
*Front brake lines replaced
*Rear calipers and pads replaced
*Bled brakes - smooth flow of fluid
*Rear disc brakes replaced 2021
 
  • check caliper slide pins
  • check caliper itself to make sure the piston isn't sticking
  • check proportioning valve to make sure fluid can retreat back to mast cylinder
  • check wheel bearings - possibly going out and binding up
  • did you replace the rotors when you did the rear brakes
I know you said you replaced the rear calipers but you could have gotten a bum set. Did you make sure the slide pins were properly lubed?
 
Thanks for sharing your info Frito

• Slide pins are good with the new set
• Dual pistons are resetting with no binding
• Proportional valve - I did not but this gives me a “To Do” task
• Wheel bearings are in good operating condition
• Have not changed the rotors but they do pass the eye test

No issues with brakes at all since changing of MC last year and there was no ABS or Service Brakes indicator alert at any time previous before the cluster task. I’m not sure but maybe I triggered something when in accessory mode and trying to stop the vehicle from rolling then applying Ebrakes and later disengaging the cluster wire harness.
 
Hmm, only other thing I can think of is something broke in the E-brake. The E-brake rarely works in these things. Mine has never properly secured the truck. Have you removed the rotors and checked inside the drum component to see if something inside the drum is binding it?
 
Thanks again bro. I did remove the rear hubs inspecting the E-brakes (cleaning/adjusting) looked within the walls of hub and could not see anything that gives me a red flag. I had all all tires off and re-inspected calipers and flex line hose, cleaned the abs mounting on the hub, re-bled all 4 calipers and still ran into the same issue. I'm thinking ABS module so I put my OBD2 to the test and came up with code C0265. I will do some research here to gain some valuable insights of what many others have encountered to fix the problem.
 
2-10-22
Within the last 3-4 days a lot has been attempted to solve my dilemma...No change.

Note: Removed and resoldered relay resistors on the ABS module and touched up on others. Re-bled calipers with a mechanic associate and he and replaced tires back on. I encountered the same binding issues and asked him to test drive to see what info he may encounter.
His findings were that on straight away conditions it was fine. However, when the vehicle is in a turning mode situation is when the bindings begin. He asked if the vehicle had hydraulic brakes? Idk was my reply (I'm not a certified mechanic btw) He popped the hood and looked towards the MC and pointed out the hydraulic booster and the lines that are attached to the power steering pump and hydroboost. There is no visible leaks, and shared his thoughts. Currently researching input from this forum and other social media GM related for guidance.

If anyone has any tips, of course it is always appreciated.
 
Hmm, since you mention it is only when turning, I wonder if there is something going on with your locking differential and that it's not a brake issue at all.
 
Update Solution:
After It has been a week now since the binding issues were resolved.
This problem was a mysterious one even for my mechanical friend but everything up to that point (see post#6) was thoroughly looked after.
Since I had no ABS light signal, and all braking components carefully inspected, and bindings are only noted during tight turns and in saying that the bindings could possibly only be from the front when steering. I asked my friend if it could be the brake booster and he said that all the lines does not have any fluid leak to detect any problems on the outside. However, their could be an internal problem within the system.
After much thought and scenarios that the binding only takes place during turns and loosens on straightaways, he suggested that the problem could be an internal issue within the booster. At this point I was out of options of self diagnosis and relied on his thoughts.

I purchased a refurbished hydro booster from a local Napa dealer and removed/replaced the unit. Very informative YouTube tips from trusted tutorials that guided me with the process. Most did say it would take 2-3 hours, for me, it was a little longer because I don't have all the right tools which would make it easier, but it is what it is. That tight space under the steering column to get to the brake assembly to remove the clip, wire harness from the brake pedal doesn't leave you much room to navigate, and if you can manage to wiggle and squirm your way throughout the process, eventually it will get done. Slow and easy was my thought process throughout my ordeal. Other than that everything was a breeze. I double checked nut/bolt securement and ran a 3/8 tubing from the return hose and bled the power steering (while monitoring the ps reservoir) until the clear fluid could be seen leading down to the drain pan, then made sure fluids were topped off, and while the front was still on jack stands I took the opportunity to change the engine oil as well.

The issue of binding brakes no longer exist within the week that the hydroboost was replaced, the truck runs smoothly and I am ecstatic to say the least.

Hope this helps if anyone else has the same issues. I appreciate this fan club for the variety of addressed concerns with probable solutions.

Have a great day!
 
This issue sounds very similiar to what my 2007 Avy began experiencing Wednesday morning. The odd part is that the night before everything was fine until I applied and released the brake pedal after leaving the truck running to check the transmission fluid. The next morning, the truck felt strange as I backed out of the driveway. Once I got going it was ok, but would reoccur each time I came to a stop. Found that the rear brakes were binding after moving from a stop (straight or making a turn). To overcome the binding, I would press the brakes hard and then the binding would lessen. ABS, Stabilitrack lights came on. My mechanic checked the traditional mechanical components first with no resolution, but code scan did show a problem with the ABS module. Going to try a reman ABS module tomorrow since I've had the warning lights come on a few times before, but not with binding as well. If that doesn't resolve the issue, he is going to try replacing the hydroboost unit.
 
CenFL Avalanche said:
This issue sounds very similiar to what my 2007 Avy began experiencing Wednesday morning. The odd part is that the night before everything was fine until I applied and released the brake pedal after leaving the truck running to check the transmission fluid. The next morning, the truck felt strange as I backed out of the driveway. Once I got going it was ok, but would reoccur each time I came to a stop. Found that the rear brakes were binding after moving from a stop (straight or making a turn). To overcome the binding, I would press the brakes hard and then the binding would lessen. ABS, Stabilitrack lights came on. My mechanic checked the traditional mechanical components first with no resolution, but code scan did show a problem with the ABS module. Going to try a reman ABS module tomorrow since I've had the warning lights come on a few times before, but not with binding as well. If that doesn't resolve the issue, he is going to try replacing the hydroboost unit.
Click to expand...
I haven’t had any issues since the swap.
Tackling the ABS module was my thought process only because it would be the lesser value of your two choices. Hope either of those fixes your issue. Have a 🤙🏽 weekend
 
The shop is waiting for the abs unit to come in. I will find out on Monday if the fix solves the problem. I need to keep the truck moving given the current truck market conditions. Have a good weekend as well!
 
CenFL Avalanche said:
This issue sounds very similiar to what my 2007 Avy began experiencing Wednesday morning. The odd part is that the night before everything was fine until I applied and released the brake pedal after leaving the truck running to check the transmission fluid. The next morning, the truck felt strange as I backed out of the driveway. Once I got going it was ok, but would reoccur each time I came to a stop. Found that the rear brakes were binding after moving from a stop (straight or making a turn). To overcome the binding, I would press the brakes hard and then the binding would lessen. ABS, Stabilitrack lights came on. My mechanic checked the traditional mechanical components first with no resolution, but code scan did show a problem with the ABS module. Going to try a reman ABS module tomorrow since I've had the warning lights come on a few times before, but not with binding as well. If that doesn't resolve the issue, he is going to try replacing the hydroboost unit.
Click to expand...
I’m wondering what the fix for your issue may have been. I am having the same exact issue. Parked the truck a few days ago and everything seemed fine. Go to drive it this afternoon, lightly pressed brake pedal to shift into gear, release and nothing, truck won’t move. Pressed the pedal all the way to the floor and it it returns, slower than normal, but it works. Problem is now while driving if I apply light brake pressure to slow it will hold that pressure to a stop, and I have to come to a complete stop or quickly depress the pedal with a lot of force to get it to return again. Suspecting hydro boost or master cylinder. No ABS code, but ABS and Stabilitrak lights come on if the pedal doesn’t fully return to zero while driving. Did pull a C0161 code for the brake light switch but read that this is likely from the brake pedal being somewhat depressed while applying the gas for an extended period of time.
 
AvPilot321 said:
I’m wondering what the fix for your issue may have been. I am having the same exact issue. Parked the truck a few days ago and everything seemed fine. Go to drive it this afternoon, lightly pressed brake pedal to shift into gear, release and nothing, truck won’t move. Pressed the pedal all the way to the floor and it it returns, slower than normal, but it works. Problem is now while driving if I apply light brake pressure to slow it will hold that pressure to a stop, and I have to come to a complete stop or quickly depress the pedal with a lot of force to get it to return again. Suspecting hydro boost or master cylinder. No ABS code, but ABS and Stabilitrak lights come on if the pedal doesn’t fully return to zero while driving. Did pull a C0161 code for the brake light switch but read that this is likely from the brake pedal being somewhat depressed while applying the gas for an extended period of time.
Click to expand...

I would try easy things like pulling the caliper pins and lubricating. Complete fluid flush if it is older than a few years. Check for any vacuum leaks.

However, if no vacuum leaks, it does sound like the booster going bad. I similar behavior on one of mine in years past.

I did have a problem in one of my old trucks where the pedal would get stuck down one or twice in the cold winter. I would pull it back up and then it wouldn't happen again for a long time, sometimes not for a year. I chalked it up to old fluid with too much moisture.
 
Last edited:
UPDATE:

Master cylinder piston seal failed and had been leaking for some time now. Brake booster was full of fluid on both sides of the diaphragm. Fluid was not clean and booster was still sticking, so I’m replacing it along with the master cylinder. Waiting for a new gasket to throw it all back together.

2007 Avalanche LTZ 5.3L with 201k miles.5859689D-CCFE-4EE8-8029-FBFBB276973B.jpegF3771DC3-319E-4B87-AC87-B282FA4C3513.jpeg
 
6 months in since my Hydroboost (HB) replacement and I noticed a leak that progressed quickly in a month (Aug). Leak location was where the master cylinder (MC) and HB connects. Researched and found it was a common problem and their is one seal in particular that needs replacing from within the HB.

I did not want to get back under the dash of the driver’s side and deal with that tight space, so I decided to take the task on by removing it near the firewall. 15mm nuts were removed from MC and the 10mm was used for the HB. The 3 PS lines were also removed ensuring the small rubber washer was still intact and all hose lines was plugged with rubber fitting to prevent leaks.

Ordered the seal replacement kit (3 seals) from Amazon. I’m gonna come back to this in a bit…

Cleaned up the HB and with a small amount of PS fluid to help with seal replacement. Two seals were used, the double loop and the duplicate one that matches the original within the HB.

After reassembly and torquing everything back to specs, it was time for test sequence. Long story short, the steering had a squealing sound and the brakes were not returning back to it’s normal position after being engaged.

I was puzzled and rethinked everything I had done from start to end. I had no choice but to disassemble the HB from the MC once more and carefully inspect the HB. The culprit was the single seal that I just replaced was twisted from within. So now that seal has been compromised I had to think of something. I asked my friend that helped me initially with this project back in Feb and he advised me to take the seal to a shop in town that manufactures high pressure seals for heavy equipment (tractors, trailers, etc). So I made the 1 hour drive into town knowing it was a 50/50 shot. I took my original seal that came with the HB and asked if they could match it up to the seal specs as best possible. I was probably there for 10 minutes max and walked out with two new seals. It was noticeably a stronger and more rigid seal than the amazon kit. $19 for the seal so I got two just in case, but my bat senses tell me that this seal won’t be changed in a very long time.

When using the new seal I borrowed my friend’s 3 point seal tool that makes it way easier to compress it within the HB. Slapping everything back on together but with a little tlc and patience during the MC and HB because I wanted to slowly ensure the spring, and seal were seeded firmly within and the knotted rod sat within the two pins from the firewall.

Although in writing it may have seemed like a walk in the park, it was anything but that. I wanted to take on the task from the under the hood and I was able to accomplish just that. Being a non-mechanic YouTube taught DIY’er it brings comfort of some sort.

Hopefully I can figure out how to share some pics…I guess I’ll hit up YouTube for that too 😂
 
808Avee said:
Hopefully I can figure out how to share some pics…I guess I’ll hit up YouTube for that too 😂
Click to expand...

Outstanding!

As for the picture posting, you will need to make a few more posts until you see "Full Member" under your name.

At that point, an "Insert Image" button will magically appear in the toolbar when you are composing your posts.

Click that button, find the picture you want to post and insert the picture at the location of your post that you desire.

Glad you were successful with this repair and I am looking forward to your pictures.

:) (y)
 
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