I don't know if i would call them spongy. But ever since i have had my truck 3 years. It seems as though i have to step on the brakes too much compared to my parents cars. I know my parents cars are newer, but it just seems i have to push them down an awful lot to come to a complete stop.
Is this common thing or maybe my brakes need something fixed?

 

If it were mine, I would flush the old fluid with new. This process not only bleed out any air, but also give you new fluid. It isn't hard, just make sure you dont' suck the reservoir down otherwise you will have to start over again with air trapped in the line. Brake fluid absorbs water out of the air, if this waterized (I just made that word up) fluid gets to the caliper and boils it will produce air. On my performance cars and motorbikes I would do a fluid exchanged every year. Especially on the bike, you can really give those brakes a work out.

 

Close inspection of soft lines are in order also..........

 

And umm. what does that mean btw..


Thx for answers guys

 

He means to check the flex lines going to the calipers and the one that comes from the frame to the rear end,they may be getting bad,when you press the brake,they may swell some.Check them close and see if you can feel any soft spots in them.

 

Have you noticed a change in your truck performance? Or just a difference from other vehicles?

If you have noticed a change (brake performance degrades) it is good to bleed (and perhaps even flush) the brake fluid.

But it might be wasted effort. All the vehicle manufacturers have different preferences for brake pedal feel. Some like to have a larger jump-in force on the booster... so when you push the brake pedal, the booster immediately jumps to a high force output into the master cylinder. This gives you the feel of having very "grabby" brakes... as soon as you touch the brake pedal, the brakes grab. Other manufacturers like to have high boost ratios. So when you push on the brake pedal, it doesn't take much force to stop the vehicle. This is good for some people (old people, weaker people, etc) but has the downside that you don't get very much "feedback" from the pedal. We call this being over-boosted. If the vehicle is over-boosted then you have trouble varying the brake pressure so you can come to a more gradual stop.

So, what I'm trying to say is that your brake system may be perfectly fine... but just tuned differently than a small car or a vehicle from Nissan. Unless you notice a difference from 3 years ago (its hard to remember as it would most likely be a gradual change) then you probably don't have any problems.

But its still good to check your flex lines for any issues. And if you decide to do some heavy towing, you may want to flush the brake fluid so the added heat will not boil your fluid.

EDIT - if you really want to see if your brakes are fine... go to the Ford dealer and test drive a new F150 (similar size as yours). I don't think Ford varies their boost curves much over the model years. So if your brakes feel the same as the new truck, you're good to go!

 

Normal vehicles are designed to use their brake fluid for the life of the vehicle. If you are not running lots of high-speed stops (aggressive driver or racing the vehicle) and do not tow constantly, there is no real need to flush the brake fluid. Just bleed the brakes when you change the pads... this will make sure there isn't any air in the system.

Performance cars and racing bikes are a different story... they run much much hotter on the brakes, hence the need to change out the fluid.

I know some service plans contradict this, but the requirements from OEMs state that the brake system has to be able to survive the life of the vehicle with original fluid. (not to imply that the service plans are just trying to make the dealers money... I would never imply that )

 

Its the abs, mine has that to it is nothing to worry about

 

NO WAY!!! Every fluid MFG i know of say change DOT 3/4 every 3 year max. True most do not this is why you see people with busted lines on the side of the road. Line offten rott from the inside out. DOT 3/4 is hydroscopic. It will putt water out of the air and absorb it in to it self.

If its brown it's got to go! If it black change it out and be ready to change out lines soon

44

 

not exactly true... every Dealer says they want to change your fluid. Not the manufacturer. But then again, dealers are always wanting to charge you too much to do little services that may or may not be needed.

As a master cylinder engineer, I see the design requirements directly from the vehicle manufacturers. New vehicles are designed to never need the brake fluid flushed under normal use.

Actually, its Hygroscopic. But yes, it can absorb moisture.

The color of the fluid is not an indicator. Engine heat will darken fluid, as will other factors. It may be dark brown or black and still be perfectly fine.

 

Don't take this the wrong way,I am not trying to bash you,but the engineering thing,man,you guys really need to got out in the real world where the vehicles are being repaired.When the brake fluid get moisture in it,and it will,it can change colors because of rust ect...And,when the water is in the brake fluid,it will make the boiling point lower,making your brakes heat up faster,causing brake fade.So the answer to that is,yes,you do need to flush the fluid sometimes.Once you get moisture in the system,not only will you get brake fade,you will get pre-mature failure of parts.It is just like coffee,the darker it gets,the worse it is.The brake fluid can absorb moisture anywhere,when you open a bottle of it,it starts collecting moisture.Let it sit on your shelf open long enough,and it will change colors.Yes,heat will make a change in colors too.Also you are talking manufactures normal use,nobody in the world drives the way the manufacture says to drive.Everybody drives differant,not under your engineering conditions at your work place.Like I said.don't take this the wrong way,if it was not for you guys we would not have much,but,you guys really need to get out in the work places too,and see how the things you creat really work under everyday situations,not lab situations.I have been working on brakes systems since 1981,I have seen it many times.

 

have you tried to mash on your brakes all the way to the floor several times in a row. It seems to help on some of my familys Ford products (mustang and f150) Something about a shop telling me it helps airbubbles get to the top

 

No problem... I agree... if people do crazy things like leave a container of brake fluid sitting open and then later add it to their vehicle, then yes - they will later need to change out the fluid.

All I am saying is that if you properly maintain your vehicle (keep the cap on the reservoir, only use good brake fluid) then you won't need to flush the fluid just because you've had the truck for 3 years.

I've said this before - if you drive very aggressively or tow large loads, you then have to be concerned with boiling your fluid. And if you have soft or spongy brakes, the brakes should be bled or flushed.

I've never said that a person should never flush their brakes. I'm just advising that its not necessary unless you have issues. I don't have the years of experience you do, but I have been working on vehicles with my Dad since I was a kid and now I do all my own maintenance on my truck.

(and yes, I "practice what I preach"... I've had my truck for 3.5 years and 40K miles and I've never flushed my brake system and it still feels fine. I clarify this as I've seen people argue points in the forums before and then they eventually reveal that they argue one thing but don't do it themselves.)

 

Get out in the REAL world? Oh man.

Unless you replace the master cylinder or a brake line, there is no need to replace the fluid. Same with the power steering.

The OP needs to check the more obvious, and easier things, first. The level of fluid in the MC and pad wear. Maybe try a different make pad.

Unless this is a recently noticed problem, it's most likely the feel between different makes, types, and sizes of the vehicles.

Do those first and we'll advise from there.

 

I skipped reading everything in this thread besides the original post.
I thought my 1999 F-150 had spongy brakes too. I tried everything. New pads, new fluid, adjusting the parking brake, etc. But, no matter how spongy I thought it was, it always stopped great, even in panic situations. If the truck is still stopping great, doesn't need new brakes or other parts, then it is probably normal. I now have an F-250 with a firm brake pedal that won't stop for *****.