Going on 3rd Brake Booster - 2005 Silverado ECSB
 

I posted a thread about my brakes locking reporting it was the booster Jan 2022. Now its about to happen again. The early signs are diminished braking almost like brake fade and eventual brakes not releasing or say applying on their own.

The OE lasted 15+ years. Could not find an OE so had to go parts store. It failed and had to go another Cardone unit. Is there a particular brand I need to see out?

If you can get an ACDelco it should be better

Have you checked Rockauto? When my original Hydroboost started leaking, I bought a new, Genuine GM one for ~$400 from Rockauto. Yes, it's 3 times the cost of a crappy reman one. But worth it if I get 21 years and 325k miles like I did from the original.

Assuming you've already looked at other possible causes? Flex hoses been done already?

GM Genuine still available for the booster and master cylinder. Just did both on my wife's '06 a few months ago for the same issue. Cause on ours is the master cylinder failed and was leaking fluid into the booster, which ruined it. Brakes would lock on their own then release later once it had cooled off and would be fine for a little while before locking up again. https://www.performancetrucks.net/fo...driving-560665

May not be the same part #'s for your particular truck so be sure you check first..

Richard

Thanks Guys, Looks like some GM units have populated the market since I was looking. I always try and go OE. I will this time.

@someotherguy That drama thread reminds me of when I was going through it the 1st time. Driving along @75mph and the truck starts shaking, rock hard pedal. I fast heel kick the pedal a few times and get relief. Not fun in rush hour traffic I-75 Atlanta. Hit them with digi temp gun and hot as hell.

All the booster tests I read up on passed. Addressed everything else. Truck has Russel SS braided lines.Did most of your thread talks of and more and finally sank in the booster was the "only thing" I had not had off. I even had the ABS unit tested to see if it needed any solder re-flows as its common on these. It was good.

It was like a new truck when I replaced the booster. Gonna get an ACDelco for sure!

Whats up with the alert to must swap to the tab held Master Cylinder? Mine is roll pins?

Ours has been on for 3.5 months and she drives quite a bit, it's held up so far but that's also not enough time to say it's gonna last forever, ya know? :)

I'm guessing the requirement to change to the other style master cylinder is because the rear section where it goes into the booster is different, so the booster is likely designed different as well. The old roll pin reservoir style has a long extension past the mounting flange where the tab reservoir style does not, check out the pics in my thread.

Richard

Link me back to your pics. I cannot seem to find it.?

Thanks. I had to swap off of Fire Fox to Chrome to get them to load. Looks like a MC & BB are in my future. The fluid is down but only 1/4". I'll report back here but it will be a Week or so before I dive in.

Fluid will go down slightly as the pads/shoes wear. If it was full when they were new, generally you wouldn't need to add any, as when you go to replace pads/shoes the level will go back up when you compress the caliper pistons.

The tell-tale of the failed master cylinder will be if you pull the master cylinder loose and it's wet at the back where it goes into the booster. Easy to do before you spend a dime on any parts.

Richard

Copy that on the pad wear thanks. I'm aware of that. My pads are not that old and I am a stickler about the fill level so I cam monitor at a glance. Opening her up will confirm I guess.
I loath going after the nuts under the dash for the booster. That clip on the rod to pedal is fun too.

It's really not that bad of a job. Took me about 1.5 hrs and I was taking it easy, and trying like hell to not spill the fluid out of the old booster and wreck the truck's paint, and also not spill it anywhere on my garage floor.

Richard

Copy that, I just loathe the job. Its the contortionist moves under the dash. I'm 6'2" 230#. I have more tools than most thank goodness. Drove her more today and its like oil on the pads. The brakes are normally pretty good. I really was thrilled when I purchased 11/2004 with GM going to the the larger rotors and drum rears impressed me. I run PFC pads up front now and they are really good braking material.
Not looking forward to the bench bleeding and such. I have a motive pressure bleeder. I just shouldn't have to be doing this again. Boo Hoo............
I'll be going in on it soon.