[JBrewster101]

I have an 06 LLY 2500HD deleted 265,000 miles.

First off started to find a bunch of leaks in the lines like the power steering and trans cooler lines of that nature so decided to replace them with OEM. Also the power steering pump started to leak like a waterfall so got the upgraded 12 spline ACDelco power steering pump (20756713). The steering was super tight and had an extra PS Gearbox and not sure if it was a reman or not but installed it. (Came with the truck when I purchased it). Next the hydroboost and master cylinder had a good leak as well. Replaced the hydroboost with the ACDelco 2011 upgraded version (178-1036) after I drilled out the peddle rod to 17mm then the master with ACDelco (18M2426).

Now my brakes are locking up.

Backstory
I bench bled the master accidentally with power steering fluid. A day later I realized what I had done and flushed it out and put brake fluid in it and bench bled it again. I also put ACDelco brand power steering fluid and brake fluid in my system for best results.

so after reading many forms about the push rod being too long on the hydroboost I added 2 #10 washers on each side between the master and hydro. Seemed to be great until the front was just locking up. Added 2 more washers between it and i was like finally fixed! After some aggressive braking and steering of about 40 minutes everything was perfect.

I kid you not, the next day I hook up the trailer and some casual driving and things heated up the front brakes were catching… It’s almost like the brake pedal does not have any play when it does this and the steering becomes extremely difficult and pulsates. I took the ABS fuse out and eliminated that factor. But once it has been running for 20min and the fluids get hot it’s almost like the fluid is expanding the hydroboost not letting it retract or there’s not enough pressure pushing back on the master. Once they lock up I can crack the bleeder screw and fluid shoots out about 3-4ft relaxing the system until another 5 minutes.

Any advise would be much appreciated!

 

[ieetgluu]

When is the last time the caliper slide pins were serviced?

Sent from my SM-N976V using Tapatalk

 

[ChevyTech77]

Anything other than brake fluid, in a brake system, will swell the rubber in the brake system and cause the brakes to lock up as you describe. It cannot be flushed out either, unfortunately. If you put the contaminated master on the truck, every brake component with rubber in it needs to be replaced and the lines flushed out before installing the new components. Master, abs unit, calipers and hoses. All of it. You should never have to add washers between a booster and master either.

 

[JBrewster101]

The right rear yesterday…. Guess I better do that as well.

done some trouble shooting today including a good drive on the hwy for about 35 min then hit town and that’s where things hit the fan. The slow driving and stop/go.
So they started grabbing and I pulled over. Only seems to be the front. I first decided to take the cap off the power steering pump to see if we had any pressure there. Normal. Then took the cap off the master. Normal. Then decided to take the master off of the hydroboost to see if that released the pressure. Nothing happened. Also tried to pump the brakes manually at the master while they were apart and was unsuccessful. I then cracked the rear lines on the master and it didn’t squirt out. Tighten it back and released the front from the master and no squirt but a steady drip/drain. The front then released. Buttoned everything back up and made it home no issues which included one red light and 2 left turns no stop.

I’m leaning towards my contaminated master since it was not doing this on the old leaky master.

I would slap the old one back on but it has been in the weather and don’t want any trash in the system.

 

[JBrewster101]

Anything other than brake fluid, in a brake system, will swell the rubber in the brake system and cause the brakes to lock up as you describe. It cannot be flushed out either, unfortunately. If you put the contaminated master on the truck, every brake component with rubber in it needs to be replaced and the lines flushed out before installing the new components. Master, abs unit, calipers and hoses. All of it. You should never have to add washers between a booster and master either.

Very costly mistake on my part. A non-organized area and no room to work… Completely my fault. I only bench bled the power steering fluid in the master. Left it in the vise and next day realized my brake fluid was still in the box in the house… so flushed the master with the new brake fluid/bench bled before installing it on the truck.

new calipers were on the list down the road but wasn’t that ready for them… planning on going with stainless steel lines this go round as well. I did not think of the ABS being contaminated too. Guess I better go look that up $$$.

 

[JBrewster101]

Wanting to give an update on everything. I replaced the master again and that solved my issue 100%! So yes the power steering fluid contaminated the master. Since I bench bled the master with power steering and never installed the master and ran fluid through I was safe from replacing calipers and lines.. so far... I did line up the master and the pin was too long on the 2011 upgraded Hydroboost I did add one #10 washer on each side. Anyways, thank you all for taking time out of your day to help me out!

Off to the next project!