OBS Low brakes

[Kraig]

Hey all,
I have a 95 f350 4x4 and I have a brake issue I can't nail down. I have brakes a plenty for the first or second push, but then on subsequent brake pedal pushes the pedal gets hard and I have little brakes. I replaced the vacuum pump as well as the booster. I'm stumped. Any ideas about this would be greatly appreciated.

 

[greenskeeper]

sounds like your still loosing vacuum

 

[Randy Bush]

If the brake pedal feels the same as with the engine off then I would agree to that you are losing to much vacuum for the booster to operate correctly. Might need to put a vacuum gauge on to see what you do have when pushing the pedal down. It will drop , but should come right back up, vacuum reading.

 

[chillman88]

Might want to check the splitter on the firewall, several people have reported them cracking and causing vacuum leaks.

 

[Kraig]

Where is that splitter?

 

[Kraig]

Oh I think I know which one your referring to. Just onboard of the HVAC box.

 

[Kraig]

What would you consider good vacuum when idking

 

[Kraig]

Ok I narrowed it down to the cab vacuum. Anyone have any ideas on places to start there? I can't find any bad pieces

 

[Randy Bush]

The dumb plastic line going to the A/C box like to brake / crack with age. If you have a vacuum pump can find the leak too.

 

[Kraig]

Ok. I traced it to the HVAC unit. I pulled the bundle of vac hoses to the outside and reconnected them and now it holds vacuum! Great so now I don't know what happened. BUT... I reassembled it and it's working now so hopefully it was tweaked enough to let a hose leak. We'll see.

 

[greenskeeper]

Ok. I traced it to the HVAC unit. I pulled the bundle of vac hoses to the outside and reconnected them and now it holds vacuum! Great so now I don't know what happened. BUT... I reassembled it and it's working now so hopefully it was tweaked enough to let a hose leak. We'll see.

If your HVAC is stuck on defrost that's a sure sign of a HVAC related vacuum leak

 

[Kraig]

My HVAC always works. So that's weird too. But I was holding vacuum when I unplugged and sealed the connector right before the last section of hose to the HVAC. But now it's works. Hopefully for a long time