04 Chevy Express 2500 Base 4.8 V8


I just bought this van a little over a month ago. So far I have put near 1k miles on it and have had no problems with it. I count myself lucky considering the style and age.

Then today happened.

Left the house with nothing out of the ordinary. Drove about 6 miles and the brakes locked solid. No pedal travel. I was stuck in the center lane so no options to investigate, could only call for a tow. Little over an hour wait for t-truck, by then pressure had lifted from the calipers and I was able to move the van a little.

Once home I looked over things and noticed the brake fluid was to the neck of the reservoir. Thinking draining some might help, I drained it to half point and tested it on my street. Didn't make it a mile and same issue.

I loosened the master cylinder from the hydro-boost about an eighth an inch and drove home. I then went to Napa and bought a new master cylinder and fluid, I hope I am right.

Sound like a master cylinder issue to you?

 

Maybe. But those brake lines are also 20 years old. If you don't change the fluid often enough it swell up the rubber lines and eats up the steel ones from the inside..

 

Thank you for the reply.

Would replacing the rubber lines and flushing the fluid be enough then?
There are no leaks and very little rust for the age of the body. Although I am tempted to change the front calipers, until today they were working fine.

Suggestions........

 

Master-cylinder did the trick, but you have me thinking; so I ordered new rubber lines, front and rear, to replace the old ones. Best to be safe than sorry when brakes are involved, eh?

Be safe.