I replaced the master cylinder in my truck(yes I bench bled it). When I replaced it I also replaced the fluid by bleeding the brakes till mostly clear fluid came out. I drove the truck afterwards and everything was great. Since then it has been parked for 2 weeks. I went to drive it yesterday and I have no brakes. Fluid level is at full just where I left it. I did not do anything special to bleed the system just the pump the pedal and crack the bleeder method. The petal goes all the way to the floor when the truck is running. Was there something else I was supposed to do? What would happen after 2 weeks that didn't happen when I replaced it? Did I not bleed the brakes enough?

 

Sounds like your master cylinder is a piece of junk tbh.

 

I'd try bleeding the system one more time and ensure that all fittings are tight and not allowing air into the system. Might still have a bit of air in the system somewhere. If that doesn't solve the issue, I'd remove the master cylinder and exchange it with your parts supplier.

 

This is the master cylinder I got. I plan on bleeding the system again once I can get some help.

http://shop.advanceautoparts.com/web...2-p#fragment-4

 

Let me guess, A1 Cardone MC right? Junk IMO. But, as stated re bleed the system. You may now have a leak some where though. Check all your lines.

 

The only other MC available was $177 which is more than 3 times the price.

Is a Dorman better? Rock auto had a Dorman for $28

 

Where would the air be trapped to effect the entire system? Is the air trapped at the MC or wheel cylinder?

 

Could be in either place. Bleed the entire system, starting with the passenger side rear first, then the driver's side rear, then the passenger side front and lastly the driver's side front. Make sure that clean fluid is coming out of the fittings and that the fluid reservoir never gets too low during the bleeding process.

 

I don't have to do anything special to bleed the ABS system right? Just bleed the whole system by pumping the pedal and crack the bleeder valve right?

Is there a proportioning valve that needs to be bled or anything?

 

That will do it. Prop valve is in-line and will be bled as part of the process.