Why does my brake pedal go to the floor?

Tiny
RONPRICE40@YAHOO.COM
  • MEMBER
  • 2000 NISSAN FRONTIER
  • 118,000 MILES
I have a 2000 Nissan Frontier, the brakes started going to the floor the first time you applied them, but would pump up. It was thought to be the master cylinder, after 2 new master cylinders it still is doing the same thing. No brakes the first time you hit the pedal will pump up the 2nd time you hit it. Replaced master cylinder and bled the system but it still does the same thing.
Do you
have the same problem?
Yes
No
Friday, April 20th, 2012 AT 11:03 PM

11 Replies

Tiny
MHPAUTOS
  • EXPERT
I would suspect there is air in the lines. These guides can help you fix it.

https://youtu.be/w7gUsj2us0U

and

https://youtu.be/WDxvEQrMkBg

and

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Please run down these guides and report back.
Was this
answer
helpful?
Yes
No
Friday, April 20th, 2012 AT 11:57 PM
Tiny
COREY H JENKINS
  • MEMBER
The guide help me fix it thank you.
Was this
answer
helpful?
Yes
No
Thursday, April 27th, 2017 AT 12:44 AM
Tiny
WILLIAMC9
  • MEMBER
  • 2000 NISSAN FRONTIER
  • 3.5L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 150,000 MILES
My brakes are going to the floor and truck is barely stopping. I replaced the master cylinder, bench bled it first then installed it. Bled all the lines working from the furthest ( rear passenger) to the front. Made sure clear fluid came out with no air, pedal was firm until I started it. Then it went to the floor again. I cracked open the ABS actuator lines and bled them ( in lines first the exit lines ). What AM I DOING WRONG? How do I bleed the ABS? Please help.
Was this
answer
helpful?
Yes
No
Thursday, May 20th, 2021 AT 10:39 AM (Merged)
Tiny
KHLOW2008
  • EXPERT
You only need to bleed the system at the wheels. Try that again and if necessary start the engine while bleeding.

Does pumping the pedal a few times with engine started makes any difference to the pedal height?
Was this
answer
helpful?
Yes
No
-1
Thursday, May 20th, 2021 AT 10:39 AM (Merged)
Tiny
WILLIAMC9
  • MEMBER
I did all you suggested, once engine is started it goes to the floor, pumping brakes has little or no difference, I think the ABS actuator has air in it. I need a way to open the valves to properly bleed them. Any Ideas?
Was this
answer
helpful?
Yes
No
+2
Thursday, May 20th, 2021 AT 10:39 AM (Merged)
Tiny
KHLOW2008
  • EXPERT
Sorry for the delay.

If pumping the pedal does not make any differences, you are correct about the ABS accumulator being the culprit but it is not air in the system that is causing this. In fact it is due to lack of back pressure.

One way of doing it is to get a scan tool to perform bleeding of the ABS system.

Try this, drive vehicle on a sandy patch and press the pedal hard to jam the brakes. The accumulator should work, keep repeating until the pedal becomes firm.
Was this
answer
helpful?
Yes
No
+2
Thursday, May 20th, 2021 AT 10:39 AM (Merged)
Tiny
JERRY LOUIS
  • MEMBER
  • 1999 NISSAN FRONTIER
  • 3.3L
  • 6 CYL
  • 4WD
  • 209,000 MILES
I had changed my brake pads about four or five months ago and when I did my piston literally fell out and I believe it was because the c-clamp I used got stuck in the hole of the piston. I then put it back together but noticed a small leak. Well I didn't repair it at the time but was never a big issue. About every other week I had to refill brake fluid. As time went on I had to refill more frequently. So about a month ago my brakes started getting worse until they finally just quit. I decided to bleed them. That back brakes were fine but not the front, pedal goes to floor and won't pump up. Traced it all the way to port on the master, not getting any brake fluid out of the one port for my front brakes. Did a bench bleed and both ports worked fine, put back on my truck and had same issue. I then called everyone and nobody knew so I went and got a used one, put it on and got great brakes. Well, here it is about a month later and now I'm having the same issue again, pedal to the floor. Yesterday I bought a rebuild kit with seals only but still the same problem. Why?
Was this
answer
helpful?
Yes
No
Thursday, May 20th, 2021 AT 10:39 AM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
Good morning,

Did you replace the caliper that came apart? If you did not, replace that caliper.

As far as the master, installing used brake parts is never a good idea. The seals internally in the master failed. They do sell the rebuild kits but they never work. The bores are aluminum and they pit internally and will not hold pressure anymore.

You need to get a rebuilt master cylinder.

Roy
Was this
answer
helpful?
Yes
No
Thursday, May 20th, 2021 AT 10:39 AM (Merged)
Tiny
JERRY LOUIS
  • MEMBER
Well it's just strange how my original master cylinder and the used one I purchased done the exact same thing. Speaking of the caliper, I replaced the seals.
Was this
answer
helpful?
Yes
No
Thursday, May 20th, 2021 AT 10:39 AM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
Again, using used parts in the brake system is never recommended. I would use a rebuilt cylinder only.

Hopefully, the caliper is not pulling air into the system causing a bad pedal as well. I would replace that as well with a rebuilt caliper.

Roy
Was this
answer
helpful?
Yes
No
Thursday, May 20th, 2021 AT 10:40 AM (Merged)
Tiny
ASEMASTER6371
  • EXPERT
Okay, I attached the procedure for replacing the master cylinder. This needs to be either new or rebuilt. I attached the part below.

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

https://www.2carpros.com/articles/how-to-bleed-or-flush-a-car-brake-system

I also attached the procedure for the calipers. You never said anything about replacing the leaking caliper after your repair.

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

https://www.2carpros.com/articles/brake-caliper-replacement

Roy
Was this
answer
helpful?
Yes
No
Thursday, May 20th, 2021 AT 10:40 AM (Merged)

Please login or register to post a reply.

Sponsored links