'99 Breaks failing

[cesarel]

Hello guys,

I have a question,

4runner 99' pads in front friction in rear. v6

the other day i was on a trip, and i did a down hill on asphalt compresioning and pushing the breaks for small ammount of times, to avoid overheating.

The thing is, everything good...

but when i ended the hill, which was about 3kms of it, i got in to a plain road, tried to hit the break, and the pedal went to the bottom, i had to use the hand break.

Any idea? the front pads are in 50% the rear i dont know.

Anyway, i took the car with the next mechanic i could found they adjusted the breaks, everything OK...

But a this sunday i went to another trip, and same story....

any ideas????????

Could this be the main pump? or the ones on each tire?

 

[Bamf_CT2004]

Typically when this happens you exceeded the posted speed limit or you MC might be on its way out

 

[Sherwood4Runner]

Typically when this happens you exceeded the posted speed limit or you MC might be on its way out

That happend to me one time in my Toyota Celica. Except all my brake fluid spewed out of one of my calipers and I lost pressure in the system. I don't think that is your problem. Could be the Master Cylinder as stated above.

 

[ajonesnv]

I would say master cylinder, but when mine went bad I could still stop, just had to press HARD!!! And it the pedal didn't go down easily either. I would check for brake fluid leak to start.

 

[cesarel]

That happend to me one time in my Toyota Celica. Except all my brake fluid spewed out of one of my calipers and I lost pressure in the system. I don't think that is your problem. Could be the Master Cylinder as stated above.

Yeha in my case i dont have any leak im thinking or the bfluid is too old, or the main pump seals are damaged and let the fluid goes through them...

 

[cesarel]

I would say master cylinder, but when mine went bad I could still stop, just had to press HARD!!! And it the pedal didn't go down easily either. I would check for brake fluid leak to start.

Yeah, no leaks, im changing my pads and rear frictions and changing all the liquid if this dont work will remove the master pump to see if there is any rust on it, in other car i have the cylinder was rusted in the inside.

 

[cesarel]

Typically when this happens you exceeded the posted speed limit or you MC might be on its way out

MC on way out?

 

[the great him]

MC on way out?

MC = master cylinder or in your words main pump, thats your problem, its bleeding off pressure some place, probably in the seals but it could be a wheel cylinder in the rear thats leaking check the read drums for wetness

 

[cesarel]

MC = master cylinder or in your words main pump, thats your problem, its bleeding off pressure some place, probably in the seals but it could be a wheel cylinder in the rear thats leaking check the read drums for wetness

hooo master cylinder *-* yeah thats what i thought, i think im going to change the pads and rear frictions and check the MC, cause i dont have leak anywhere.

So im guessing is bad seals or rust inside.

tks for the tip.