Question about 1992 Ford F250

2 Answers

Brake goes to floor with new mater cylinder question about power booster

Thanks to all who have helped me with this. Please tell me how the power booster could be related to the loss of pressure. There is vacuum at the booster and no obvious leaks. The pedal is hard when the truck is not running. As soon as it starts you can push the pedal to the floor. I don't understand how a problem with the booster has a relation to the plunger moving too far in the cylinder. Please explain as I could see if there is a problem with the booster that I would have a hard pedal but not soft. Thanks again. Reg.

Posted by on

  • Anonymous Mar 14, 2014

    replaced vacuum power brake booster now brake pedal won't cume up

  • Anonymous Mar 19, 2014

    i got a f150 everytime i put the break paddle to the floor, and put the truck in gear. the truck is missing. what do i need to do, please help me to get rid out of this situation. thank you.



2 Answers

  • Level 1:

    An expert who has achieved level 1.


    An expert whose answer got voted for 2 times.

  • Contributor
  • 2 Answers

If your pressure is good in till you start your truck it is the power booster. i just fixed this problem. If it is not your master then that is the problem. I had to replace the whole brake system to find this out.

Posted on Dec 18, 2008

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has written 7 tips or uploaded 3 video tips

  • Master
  • 674 Answers

All a brake booster does is boost your peddal effort .
so it can not be related to your fluid pressure loss.
my question is are you loosing brake fluid?
its possible you have a bad master cyl or you need to bleed your brakes.
let me know if ya need more help

Posted on Nov 01, 2008

  • 1 more comment 
  • paul erickson
    paul erickson Nov 01, 2008

    also wanted to make a note that if your back brakes are not adjusted up .

    most of your brake fluid is going to the rear brakes just to make up for the brakes not being adjusted.

    that is where i would start after reading your previous post and the stupid answers you recieved.

    later paul

  • paul erickson
    paul erickson Nov 01, 2008

    just to give you an idea of what is inside you drums

    are your rear axels full floating?

  • paul erickson
    paul erickson Nov 01, 2008

    not sur if your familar with adjusting rear brakes but here is a good web site that covers it" target="_blank" rel="nofollow" >how to adjust drum brakes



1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

YES on a 91 Acura Legend my brake pedal goes straight to the floor there's no pressure at all when the car is off is that the power booster

no-- it is a lack of fluid in the master cylinder or air in the brake system
a power booster only assists the brake action and the pedal push rod goes through it into the master cylinder
check for leaks in the system , refill the brake reservoir and bleed the brake system
it may be a failed master cylinder rubbers

Aug 09, 2015 | Acura Cars & Trucks

1 Answer

How to detect if power booster bad

If power booster is bad it will cause a hard pedal, If master cylinder is bad. pedal will go to floor .running or not. when the brake pedal goes down at a standing stop, it is the master cylinder losing vacuum.( replace). Hope this helps you!

Jul 21, 2014 | 2000 Chevrolet Blazer

1 Answer

2001 Silverado 2500 HD Why Rear brakes don't work after I installed new hydro-boost power booster, master cylinder, calipers, and pads. I bled master cylinder before installing, and brakes beginn

Hello Patricia,

Have you checked the master brake cylinder reservoir for brake fluid loss?

I don't suspect the master cylinder as you have replaced it... but am more suspect of a leaking brake line or fitting which should have
been discovered when you had the system bled.

The only time I ever had a rear brake problem with a 2500 series Chevrolet was due to seized rear brake caliper guide your calipers are also new that is not your problem.

If your brake pedal feels spongy and travels to the floor board you have air in the system, a brake fluid leak or a failure in the power steering system, such as a broken hose, broken power steering pump drive belt, or failed pump, would result in a loss of pressure to both the hydro-boost and steering.

Find more information here:

. Hydro Boost Power Assist Systems Operation Diagnosis and Repair

Jul 23, 2017 | 2001 Chevrolet Silverado 2500HD

1 Answer

Ford focas all disks and pads /rear shoes are new changed disks /pads today but pedal still goes to floor pedal is hard until you start engine

The problem is likely either the brake booster which is vacuum powered or the brake master cylinder -- brake booster would be leaking air, master cylinder would be leaking fluid by the O-ring on the piston (internally "leaking by").

This sounds more like a booster failure since the pedal gets soft when engine is started. But probably a good idea to replace both at the same time.

More info, please let me know.


Oct 02, 2009 | 2001 Ford Focus

2 Answers


2 common causes for this are air in the, system, and pads are worn down causing the calipers to go furthur out thus reducing pressure (disc brakes)plz rate-bozcro

Sep 16, 2009 | 1996 Ford Thunderbird LX

3 Answers


bad power booster

Jul 13, 2009 | 2002 Nissan Sentra

1 Answer

Need to replace a brake booster on a 1998 chevy cavalier

get ready for some need to remove the master cylinder nuts that hold master cylinder to brake booster.once you remove nuts you have 2 choices remove master cylinder to remove booster. to keep from bending brake lines.or you can leave master cylinder in pull it toward you easily careful dont bend lines .disconnect vacuum line at booster .go inside vechicle to floor on driver side loosen four nuts on floor to booster .disconnect power brake push rod from brake pedal .dont force pushrod to the sides when disconnecting it.remove four booster nuts then remove booster.when in stalling the new booster loosely install four nuts then connect the push rod to the brake pedal .install new clip tighten the booster unit .if you decide to remove master cylinder use inline wrenches on master cylinder to remove lines.also plug the master cylinder brake line holes to keep from losing all brake fluid.

Apr 26, 2009 | 1998 Chevrolet Cavalier

2 Answers

2002 Toyota Sequoia power brake booster % master cylinder are bad

Mr. Clark:
It would be extraordinary for a technician to recommend a booster and a master cylinder with no previous mention from you of a possible problem in this area. In other words, the technician had no business looking at the m/cyl or the booster, unless you told him that your braking was deficient.
Here is what REALLY happened: Somewhere, I'd bet, your brake light came on, and somebody "topped off" the master cylinder, to shut the light off. Now, please understand that the brake fluid level in the master cylinder reservoir DROPS PROPORTIONALLY to the wear of the brake pads. When the tech replaced the front brake pads, he obviously had to squeeze the caliper pistons into the housings to allow the insertion of the new pads. This action forced the brake fluid from the now-compressed caliper pistons BACK into the master cylinder, and it sprayed out from under the cap, coating the cylinder and the booster. Tell that repair service that you do NOT need a booster and a master cylinder, THEY caused the problem with the fluid being everywhere. I am confident that I just saved you a significent amount of money that you do NOT need to spend. Have a great day.

Dec 29, 2008 | 2002 Toyota Sequoia

2 Answers

1989 Ford F350 2 wheel drive dually 460 ci gas motor

5 Inspect Brake Fluid Type Brake fluid loss or contamination grey_line.gif 10 Inspect Master Cylinder (Brake System) Worn or leaking brake master cylinder. grey_line.gif 11 Inspect Brake Power Booster Damaged booster vacuum line/check valve, or diaphram

Nov 24, 2008 | 1989 Ford F 350

2 Answers

97 ford e350 brake pedal goes to the floor...

are your rear drums set up? why did you bleed the brakes. when only when you installed new pads?

Sep 11, 2008 | 2002 Ford E350

Not finding what you are looking for?
1992 Ford F250 Logo

386 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts


Level 3 Expert

78267 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers


Level 3 Expert

5655 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides