Hey guys,
2004 SLT 140k - I'm having a nasty problem with my brake system after a fluid contamination in the brake master. Unfortunately the foreign fluid was in for more than a month.
Since the mishap I have:
1. flushed thru each bleeder valve
2. replaced the brake master
3. replaced all 4 calipers
Soon after I replaced everything I noticed my brakes would gradually tighten until I was unable to move. Most time it has seized up within 10 minutes or 2mi. Once the brakes seize up and I pull over to let it cool off, the brake pedal becomes rock hard and kicks back (best way I can think to describe it) when I apply pressure. After an hour or so the pressure releases and my truck drives fine.
The 2 possible problems I can think of is the rubber hoses at each wheel are shot OR the ABS module was damaged by the p/s fluid. I have tried only using the parking brake but the brakes gradually seize and I'm stuck.

 

Added progress:
I removed the fuse for the ABS before driving home and surprise surprise the brake were still seizing up after about 10 minutes. At least the ABS was jacked up.
I ended up making the drive to get a set of new hoses for the front and worked in the dark to get it done. After the replacement I took a 20 minute test drive with no issues. No issues again this morning
Does anyone have experience fixing the system after this has happened? Is there anything else that needs to be done?

 

Hoses swell internally, hence the reason they look fine on the outside, but become restrictive on the inside...


No different than Lary's heart arteries and veins that surround his ticker. Obviously, your truck isn't eating bacon everyday, but something causes them to fail. I guess locking up is better than losing all the fluid through a blow out.


For me, I would replace all the brake hoses on the truck, as mine has 3 in the front and one in the back. Then flush the fluid out of it till it was clean as new coming through. Always remove the fluid from the reservoir first, with a suctioning tool, fill with clean new fluid, so you're not dragging all the gunk through the system.




Should be good to go after that, no ?

 

Now that the hoses have been replaced it has drastically reduced the problem. But I noticed the front left starting to tighten up right as I pulled in the driveway. I pumped the brake pedal a few times nice and smooth and the pressure went back to normal and the seize loosened. I plan on pulling the caliper off tonight to check if there is a manufacturing cast burr that would be catching on the brake pad. Just kinda thinking out loud. Any ideas as to why one of the calipers would be getting hung up?

 

If you are tearing down the caliper, check to see if the piston is metal or phenolic, if phenolic they start to deteriating after a few years and swell causing it seize up, normal brown color;