Brake issue after swapping rear pads

[Bedhead514]

Discovered rear brake pads were low and recently replaced them in the driveway. After replacement, rear driver side caliper is sticking and won't release (rotor gets very hot and burning smell). I cracked the bleeder screw to attempt to release pressure and see if caliper would release. Didn't release without c-clamp and fluid was very dirty that came out. I decided to do a "flush" and see if I could push the dirty fluid out. What came out is the dark stuff pictured (clear fluid is what I put in the bottle before bleeding).

How concerned should I be with fluid like this in the brake lines? Could this cause random ABS/Brake lights on the dash? Should I do brake system overhaul?

 

[swathdiver]

Discovered rear brake pads were low and recently replaced them in the driveway. After replacement, rear driver side caliper is sticking and won't release (rotor gets very hot and burning smell). I cracked the bleeder screw to attempt to release pressure and see if caliper would release. Didn't release without c-clamp and fluid was very dirty that came out. I decided to do a "flush" and see if I could push the dirty fluid out. What came out is the dark stuff pictured (clear fluid is what I put in the bottle before bleeding).

How concerned should I be with fluid like this in the brake lines? Could this cause random ABS/Brake lights on the dash? Should I do brake system overhaul?


View attachment 478240

Well, clean fluid is better than dirty fluid. However, your truck is at least 12 years old and by about 150K or so the calipers are due for replacement or overhaul. Some get to 200K or more. I made it to the 150s myself on one and 160s on another before replacing the front calipers and rebuilding the rears.

 

[Marky Dissod]

My guess is you should put fresh brake fluid in to push the old brake fluid out.

 

[OR VietVet]

Besides not knowing if the caliper slides are also sticking, you did not talk about cleaning and lubing them, That dirty fluid causes problems internally. The dark means water in the fluid, right along with dirt. That will effect the caliper piston seals and not allow smooth piston movement.

 

[Bedhead514]

Well, clean fluid is better than dirty fluid. However, your truck is at least 12 years old and by about 150K or so the calipers are due for replacement or overhaul. Some get to 200K or more. I made it to the 150s myself on one and 160s on another before replacing the front calipers and rebuilding the rears.

Mine is an 07 with 134k, I've only owned it since Nov. Previous owner had some brake work done, but nothing with the rear calipers so I'm going to replace those. Thanks for the rec.

 

[OR VietVet]

I think one of the things to keep in mind is where you live. Salt on roads states are harder on caliper assemblies.

 

[Joseph Garcia]

As @OR VietVet asked, can you tell us how you cleaned and lubed the calipers? I often find that some folks do not fully clean and lube the caliper assembly, particularly the slide pins, and this leads to sticking calipers.

 

[mikez71]

I don't know that dirty fluid would cause the brake light to turn on.
If your fluid looks topped off, I would get it scanned if the light is still on.

One more thing I've heard can cause brakes to lock up, are bad brake hoses.

 

[donjetman]

I don't know that dirty fluid would cause the brake light to turn on.
If your fluid looks topped off, I would get it scanned if the light is still on.

One more thing I've heard can cause brakes to lock up, are bad brake hoses.

yep, I had a hose collapse internally once. Since then (40+ yrs) I always replace hoses when doing brakes.

 

[strutaeng]

Unless you know the fluid has been replaced within the service life, probably a good idea to flush the entire old fluid and purge each wheel.

Ditto on lubricating the caliper pins.

I don't think old fluid would cause ABS/brake light, but a sticky caliper may?

Sticky caliper may also be a collapsed hose.

I've got a 99 Silverado and 06 Suburban, each with close to 280k, and calipers are original. Silverado got the new front brake caliper a few months ago, but was purely for performance upgrade, original calipers were still working fine. No rust here though.

Also, may be a good idea to temporarily remove your ABS fuse, just to rule out that the EBCM is somehow not applying hydraulic pressure to that wheel due to some fault or code. You don't have any of the Stabilitrak(?) lights on your dash on, right? No codes for wheel speed sensors?

 

[mikez71]

This reminds me of the Tech 2 ABS bleed.. I tried it but was unsuccesful..
It runs a long time, and makes the ABS activate louder than you've ever heard.

I did front left, then front right the bleeder screw rotated closed while I was inside pushing on brake pedal.
(because that's what the Tech 2 told me to do, not sure if it's needed with pressure bleeder attached)
Then it wanted to move to the left front again..

Had to go, so I just finished with a regular pressure bleed and will do ABS next time..
Bleeding brakes with truck on ground really sucks!
Putting it on stands next time, wheels off..

 

[West 1]

Lots of good advice already offered. One thing you mentioned was you opened the bleed screw on the stuck caliper and it did not release?
That eliminates some possibilities.
If no fluid came out is it possible the bleed screw is plugged? Remove it totally and see if fluid releases.

If fluid is not causing your stuck brake a new caliper is in order or a rebuild to free your stuck piston.

Probably when you compressed the caliper piston to install new brakes you pushed it back into all the dirt in the system and the piston got sticky. When you apply the brakes and release the piston goes out applying pressure but it no longer retracts.

Common issue. They used to sell rebuild kits for calipers but due to liabilty and the time it takes to rebuild one every shop now does a replacement with a new or professionally rebuilt caliper.

Flush the system completely before installing your new caliper or you will pump old dirt into the new caliper and shorten their life.

FYI: in my 2008 which I bought last year I flushed almost 3 quarts of brake fluid through it to get good clean fluid at all 4 corners. The order of flushing is up for discussion. You don’t want to flush the ABS unit when you have dirty fluid being supplied. I flushed the Master cylinder and all 4 brakes before doing the ABS system with a scan tool. Then I finished with one more flush at each wheel. Took time but the ABS flush put more dirt into my system and I could see dirty fluid come out at each wheel after the abs bleed. Time consuming yes but I know it is now clean and good for a while. I am sure the fluid flushed had been in there since 2008. I did use a motive pressure flush unit which supplied clean fluid under 18 PSI of pressure as I did this process. Saved a lot of time.

 

[Fless]

I recommend using DOT 4 brake fluid; it's an upgrade from DOT 3. Get rid of any DOT 3 you have around.

 

[West 1]

I always buy Dot 4 also but if you look at the SAE specs for brake fluid the only difference is temperature capability and Dot 3 and Dot for are pretty close. I think it is only about 50*F difference. The OEM installs Dot 3 in most vehicles so it is not junk, no need to throw it out but Dot 4 is a little better. If you push the brakes till the fluid boils you are in deep trouble for sure. In 50 years of driving and lots of towing I have never had brake fluid boil but I keep my brakes in good shape normally.

 

[strutaeng]

Yeah, I've switched to DOT 4, but was kinda on the fence about staying with DOT 3.

Read some guys that were saying unless you are racing with a lot of curves and hard braking, DOT 3 is fine and you wouldn't really know the difference between the 2 for daily driving. I believe the only downside to 4 is, the life is shorter? IDK?

 

[mikez71]

I put this stuff in.. No idea if good/bad.. just felt like trying it I guess..
I'll probably never know the difference..

Bosch ESI6 DOT 5.1

More Information for BOSCH ESI6

And the material safety data shows toxicity amounts to a rabbit(dermal) and a rat(oral)..

https://www.rockauto.com/info/23/3772694pdf.pdf

I did boil the brake fluid in my cousins new-at-the-time honda civic in mountain twisties once...
Didn't abuse it too long... Pedal went back to normal after a few minutes..

Really lucky they didn't go out when driving hard.. (everyone was slowing for a break when I first noticed it!)
At one point I had the passenger front tire off the road, on the gravel outside edge of cliff..
Luckily was able to coast out of the turn, because I was too scared to touch the brakes mid turn.

(Oh my cousin had a good view.. he told me never do that again.. I agreed!)
Maybe braking would have been OK, 3 tires on pavement.. I'll never know, I don't need to know!
Sometimes you look back and realize... "I was just a lucky idiot.. "

 

[West 1]

Dot 5.1 is fully compatible with any brake system except silcone Dot 5 fluid. Like Dot 4 it is one step better at handling heat. But not much maybe 50* more than Dot 4. I looked up the specs once and was surprised how close they were in temp ratings. Dot 5.1 is good for sure if you need that protection.

I should have added that Dot 3, Dot 4 and Dot 5.1 are fully interchangeable, you can top off a system with any of these three and have zero problems. The Silicone Dot 5 is very unique and will not mix with any of the other brake fluids. Has its own list of good and unique properties and many brake parts suppliers will void a warranty if you use Dot 5 in a system using their products. It is not bad, just unique and has special rules to follow that can't be broken and no other brake fluid is compatible with it.