[SOLVED] Brakes squishy after brake upgrade

[Manon407]

Hi everyone, I recently upgraded the front brakes of my 08 Escalade EXT to the 2020 Silverado 4 piston brakes. I've done this swap twice on my GMT800s with no issues, however when I did it to my GMT900 Escalade EXT, the brakes get squishy once I turn on the engine. I bled the brakes as normal, furthest from the reservoir first, and the pedal got hard when the engine is turned off. Once I turn on the engine, the brakes are super mushy and don't brake at all. I bled the ABS system with a scan tool and that didn't make a difference either. Next thing I will try is bleeding the brakes with the engine running because of the hydroboost system apparently using power steering as a booster, which my GMT800s didn't have.

Am I going down the wrong path? Does anyone know something I don't? I appreciate any help I can get!

 

[mikez71]

Quick search says something about bleeding the master cylinder.
Think you need a helper to push the pedal as you loosen and tighten the master cylinder connections, before letting the pedal back up.

Manual — 2008 Cadillac Escalade EXT AWD V8-6.2L Service Manual | Operation CHARM

Detailed repair manual for the 2008 Cadillac Escalade EXT AWD V8-6.2L.

charm.li

 

[Manon407]

Quick search says something about bleeding the master cylinder.
Think you need a helper to push the pedal as you loosen and tighten the master cylinder connections, before letting the pedal back up.

Manual — 2008 Cadillac Escalade EXT AWD V8-6.2L Service Manual | Operation CHARM

Detailed repair manual for the 2008 Cadillac Escalade EXT AWD V8-6.2L.

charm.li

I Did see that, but didn't really understand how air could've gotten trapped there if my reservoir was full the entire time. Either way, it's simple enough to do and a fair point so I'll try that.

 

[mikez71]

Yea.. I wouldn't *think* it should be necessary if reservoir was full the entire time..
Bleeder screws on top side of caliper?

 

[j91z28d1]

pressure bleeder on the master, something like the motive one is a good value and is very handy while running the auto bleed. I believe most manauls actually call for something like 15psi on top of the master while running the program.

 

[j91z28d1]

oh and just because it seems to pop of up from time to time. are your calipers on the correct side so that the bleeder valve is facing up? sometimes they end up facing down and you'll never get air out of them.

 

[Manon407]

Yea.. I wouldn't *think* it should be necessary if reservoir was full the entire time..
Bleeder screws on top side of caliper?

You and j91z28d1 mentioned it, but I'll also check the orientation of the bleeder valve because that might be it. I got this used set of rotors off a dude on FB Marketplace so who knows if he even gave me one of each side. Appreciate the help and will update once I check them out!

 

[Fless]

 

[Manon407]

Message received! I'll check the orientation because I think you guys are onto something.

 

[Manon407]

I DID put them on backwards, I moved them to the right sides and went to bleed the brakes again in all 4 corners just to be sure. The first 3 corners were fine, but once I got to the driver's front corner, it just kept spitting air out of it nonstop. I hit the caliper with a hammer, bled the master cylinder lines and even reconnected my old brakes from before the swap and it seems to be a constant thing now. So I sprayed all of the connections from the brake banjo bolt to the caliper, and the connection from the brake hose to the frame's brake hose and all the connections up top near the master cylinder. No bubbles, yet the air that kept getting bled from the driver's front kept coming out almost white like it was getting aerated somehow. I gotta figure this out now. Happy new years everyone!

 

[j91z28d1]

are you using a vacuum bleeder?

 

[West 1]

Spend the money and get a power bleeder. The motive unit works well. Not a vacuum bleeder but a pressure bleeder. Once hooked up to a scan tool bleed everything, it might take 2 quarts of fluid to bleed the system and the ABS lines. $15 in fluid is cheap. While at it buy the catch tank to bleed into. They are vented and have a magnet to mount as you bleed. Keeps things neat. Don’t use more than 15 - 20 psi or sometimes you start creating issues. Good Luck

PS: over the years I have tried many other methods, I usually am working alone on jobs. The motive tool was a great investment. I did modify the tank and added a schraeder valve so I can hook my compressor up dialed back to 15 psi and never have to pump it up while bleeding. Works fast, do it once and you are done. With the truck up on stands and all tires removed it takes about 45 minutes start to finish.

 

[mikez71]

x3 on the motive pressure bleeder!

No more finding a second person, or hand pumping the mityvac 100 times just to draw bubbles in through the bleeder threads..

 

[Manon407]

Thanks for the recommendations, I was definitely looking to pick up a Motive pressure bleeder after this Fiasco. I tried using the Vacuum bleeder but it didn't work too well because of spacing and I couldn't get my hands in a way to make it work, but I've used it on other stuff before. Pressure bleeder is definitely being picked up now though.

 

[Charlie207]

Thanks for the recommendations, I was definitely looking to pick up a Motive pressure bleeder after this Fiasco. I tried using the pressure bleeder but it didn't work too well because of spacing and I couldn't get my hands in a way to make it work, but I've used it on other stuff before. Pressure bleeder is definitely being picked up now though.

Another +1 for the Motive pressure bleeder. It's a great tool, especially with the ability to swap different brake fluid resevoir caps for different cars.

I've used it on my Yukon and Silverado many times, and never had to do the ABS reset with my Tech2... it just worked.

 

[Charlie207]

Hi everyone, I recently upgraded the front brakes of my 08 Escalade EXT to the 2020 Silverado 4 piston brakes. I've done this swap twice on my GMT800s with no issues, however when I did it to my GMT900 Escalade EXT, the brakes get squishy once I turn on the engine. I bled the brakes as normal, furthest from the reservoir first, and the pedal got hard when the engine is turned off. Once I turn on the engine, the brakes are super mushy and don't brake at all. I bled the ABS system with a scan tool and that didn't make a difference either. Next thing I will try is bleeding the brakes with the engine running because of the hydroboost system apparently using power steering as a booster, which my GMT800s didn't have.

Am I going down the wrong path? Does anyone know something I don't? I appreciate any help I can get!

Can you share the part numbers for those front calipers? I've been mulling a front brake upgrade for a while.

 

[Manon407]

Can you share the part numbers for those front calipers? I've been mulling a front brake upgrade for a while.

Yeah, here's the GM PN for both.

Front Left: GM GENUINE 13545382
Front Right: GM GENUINE 13545383

I got mine from some dude off Facebook that I bought my other 2 sets from and they've always been good. Rockauto has them for around 100 each plus core charge. It comes from a 2020 Silverado 5.3L with 4 piston front brakes in case you need to look up pads and rotors.

 

[Charlie207]

Yeah, here's the GM PN for both.

Front Left: GM GENUINE 13545382
Front Right: GM GENUINE 13545383

I got mine from some dude off Facebook that I bought my other 2 sets from and they've always been good. Rockauto has them for around 100 each plus core charge. It comes from a 2020 Silverado 5.3L with 4 piston front brakes in case you need to look up pads and rotors.

Did you need to stack washers to center the calipers over the rotors?

I suppose there's a kit and/or mounting guide somewhere.

 

[Manon407]

Did you need to stack washers to center the calipers over the rotors?

I suppose there's a kit and/or mounting guide somewhere.

I did on my GMT800s, but on my GMT900 it looks like I didn't need to. I still bought some just in case, but didn't end up using them. You can find some 9/16 flat washers at home depot or ace hardware that you can get as a backup though in case you might need to.

 

[Manon407]

To everyone who recommended the pressure bleeder, thank you! It's a game changer for brake bleeds. I've never had such stubborn air in the system before, and this just took care of it like it was nothing. I'm happy to report that nothing is wrong, there was just air still in the system after all the bleeding I did. One round with the pressure bleeder and all is good. I also used the Orion Motor Tech one, not the Motive.