Brake pressurizing while driving causing hard braking

[emmwhat]

I searched the forums and google already and couldn't find any related threads, but if you know of one let me know.

I know the ABS is supposed to pressurize, mine seems to do it pretty often, maybe every 2 - 3 brakes. The problem is sometimes, pretty often, when I'm braking lightly the system will pressurize and then the truck will feel like I just slammed on the brakes when I didn't. It's not hard enough to be dangerous, just enough to be extremely annoying. Does anyone else have this problem? And on average, how often do you hear your pump running?

Thanks
-Steve

 

[zonianbrat]

I have a problem similar to this one. Mine does not feel like I slammed on the brakes. The brakes stay pretty normal but the pump is now running about every 20 to 30 seconds. I think I am losing pressure somewhere. I might have to take it into the shop while I still have a warranty. If you find anything out please let me know.

 

[MikeInNH]

When was the last time you had brake fluid flushed.

 

[zonianbrat]

I'm not sure I have ever had mine changed. Think that would help? Sorry I am not meaning to thread jack it just seems like mine and the original posters problems are similar

 

[MikeInNH]

Brake fluid is Hygroscopy. This means it can absorb water. Water does not react the same as brake fluid. Having contaminated brake fluid can cause a lot of braking problems. It might be worth flushing it out. I do mine about every other year (about 80k miles). And when I do I always notice a big difference.

 

[emmwhat]

Sounds good to me! I just got the 4runner about 2 months ago from a dealership around here, it's about to roll over 100,000 miles, it was only owned by one other person and luckily they took it to the dealership for everything, so I'm going to look through the service records on the toyota owners site and see if it's ever been done before, I'll probably just end up getting the flush done regardless, hopefully that'll help! Thanks a lot!