[Robert Blumberg]

Hi, well for the last 6 hours i been trying to bleed my father 2008 f-250 6.4l Diesel engine. So what i know is that this truck has a vacuum system. I dont know if you need the truck on when bleeding. But when i turn it on i lose all pressure in the system. I put two new calipers on the front end and one on the left rear a few months ago. I did not have to have the truck on before and it work out fine. But i cant find out why this truck wont bleed. Every time we push on the pedal no air will come out of the system.

Please help i really dont know what to do from here no one seems to have a forum on this so i started one. Thanks for reading.

 

[fatboytx]

"Depending on application, some vehicles will be equipped with a Hydro-Boost brake booster and some will be equipped with a standard vacuum brake booster. The Hydro-Boost system uses the power steering system to boost brake pedal pressure while the vacuum system uses engine manifold vacuum to boost brake pedal pressure. "


I've only seen hydro-boost on these trucks ... not vacuum. However, both methods boost your foot pressure on the bake pedal when actuating the brake master. So, when you bleed the brakes manually with the engine off its a much different feel to the pedal than when engine is running. Make sense.



"When a DTC is set in the ABS module, the ABS module will send a message to the instrument cluster via the HS-CAN bus. The instrument cluster will then illuminate the red brake warning indicator and the yellow ABS warning indicator. "


I assume you've no trouble lights on your dash?


I think what your saying is that you don't have a good pedal till you start the truck and it then boosts the brake pressure to the master cylinder properly. This makes sense to me. Not an issue. But you then say that your not getting any air out. Hmm. Do you get fluid out? Anything? Nothing at all? Then I'd say your brake master cylinder is shot assuming that it has sufficient fluid in it.

Naturally this is internet advice and not worth a nickle. -FB