Like the post says I had fluid under my hood by the PS fluid reservoir. I replaced the pump. Now my brakes go to the floor. I turned the wheel slowly back and forth 60 times like I read no foam coming in the system. Then bled the it from the return line going to the hydroboost Pumping the brakes and turning. The wheel. Went through and make sure all my lines are tight. Power steering feels fine now but brakes still to the floor with a half bar drop in the RPM when brake is applied. PleAse help its my daily and need it back on the road.
PS pump change now no brake HELP!
- Thread starter MDpsd06
- Start date
So you have a soft pedal, not a hard one? That indicates probably a master issue or an hcu issue. Unless you removed any brake lines for some reason when you were doing th pump. Air in the system, or lack of power steering assist would cause you to have a very hard pedal.
I have soft pedel and when you out a little harder it just goes right to the floor. No brake lines where removed, just high pressure line and return line to the pump. Just to check I went through and bled each caliper no air in them. Bled the master cylinder no air in that. I'm leaning towards a hydro issue? I did find the high pressure line rifht where it went into the hydra system had some fluid on it.
IHPowerstroke7.3
New member
Trying to think how the 6.0's were, but did you disconnect the lines at the hydro boost? Are they side by side where they connect at the firewall? Possible you hooked them up backwards, wil give you a weird pedal.
I didn't disconnect them at the hydroboost. I just pulled the lines off the PSpump then reconnected onto the new unit.
IHPowerstroke7.3
New member
Well that eliminates that possibility. A little rpm drop is pretty normal with hydro boost. When you say brakes go to the floor, do you mean if you keep pressing the pedal, it will very slowiy sink to the floor? But you still have brakes? Does the pedal sink when the truck is not running?
If I press the pedal hard enough it will just go right to the floor, not a slow thing just as much pressure as I put on it sends it to the floor that speed. I still do have brakes. I put it in reverse and drive in the driveway and it would still brake and also go right to the floor of I pressed hard enough. When the truck is not running the brakes feel normal. As soon as it's turned on it when the problem occurs
No issue before this that I could tell. If I braked the truck wanted to sort of pull to the right but I thought that was because I had a a bunch of play in my wheel.
So new symptoms. I decided to just take it for a drive, brakes feel great on the road can't push them further then usual stop great. Come to a complete stop push a a little bit down to the floor again and now letting out a hissing noise. I'm thinking hydro booster?
Hydroboost*
A hydroboost typically wont make a hissing noise, as there is no vacuum or atmospheric pressure on it. Is it more of a whining noise? If so that is air left over in the power steering and it should bleed out after a while.
No I think I would describe it more as a hissing over a whine. sorry forgot to put in the last post, in drive brakes applied the wheel is a hard as heck or not at all possible to turn left and right.
dsberman94
Well-known member
Sounds like you've got something backwards
Brake boosters can only provide a lack of assist, they cannot cause a soft or low brake pedal unless they are mechanically damaged.
Since it now stops normally, what you are experiencing may be booster step through. That's essentially when you push the pedal to the floor at a stop, increasing the pressure in the system and flexing the seals/hoses. That is a normal condition. If it brakes normally, the system is operating properly.
I'll have to check in park or neutral. I disconnected both the high pressure line and the return line off the power steering pump. Put the new Teflon ring on the high pressure line. Did not remove anything else or remove either from anywhere else then the power steering pump. Put the new one in and put them right back in.
I can't have anything backwards. I only took two lines off the power steering pump. One is threaded and I tookoff and out on with a crowfoot. And the other is the rubber return line used with a clmap
