I have a 2008 F150 5.4 with 11,000 miles that the brake reservoir is below the minimum line on the fill. I do not see any leaks. Where is the fluid going and what brake fluid should I use to top it off.

 

If its just below the lower line,Id think that you have no leaks.
Usually on new vehicles the normal "break in" of the pads will cause a slightly low resirvoir.As the pads wear(break in) fluid replaces the difference in the brake caliper.Top it off,and just keep an eye on it.
Concerning what type I cant answer that.Ive always used I believe "DOT3" fluid.

I consdier your 08 as new since it only has 11,000 miles.......

 

My manual says what kind of brake fluid to use, but I dont remember what it was. The local parts store should know if you dont have one. The cheap pads they put on these trucks at the factory prob got broke in, (thinner), and there is now more fluid in the caliper piston cylinder.

 

I just encountered the same thing with my 08' with 16000 miles. Level was below min, i noticed it when i started feeling it in the steering wheel, begging for fluid. There were no leaks, havnt seen a drop since i bought the truck and still at min at operation temp... so i added some to the max line, then a day later the level is over the max line...so i suggest you fill about to the 3/4 line and then run it and check it a day later. I agree its from the brake linings being worn in and needing more fluid to take up the space the caliper is pushing out, pretty normal.

Use Mercon V tran fluid. I believe thats what is recommended.

 

Mercon V trans fluid in a Brake Reservoir!?!?! Where did you get that from? Do NOT do this. You will swell your seals and have to replace EVERYTHING that that fluid touches in your brake system. You use Dot 3 Brake fluid in any car/light truck application. The only thing you would use trans fluid for in a brake system is a Hydro-boost brake booster application found in super duty trucks. The hydro boost system uses power steering fluid as a brake booster instead of the common vacuum boost system....

 

My mistake, my mistake. Dot 3 brake fluid. Mercon V tranie fluid in the powersteering which is the problem i had been outlining, saying i could feel it in the steering wheel. I dont know what i was thinking when i responded this this thread. good catch though.

 

You should never have to top off the brake fluid. If its really low, then you have a leak or your brakes are getting worn. Look for a leak, if there is no leak, then check the brake pads to see how worn they are.

 

there is not a problem
its normal to add a little fluid once awhile
did some of you guys just start driving?

 

Then if it is normal to "Add" fluid, where is this fluid going? You should never have to top it off. If you are low on fluid, you either have excessively worn pads or shoes that need to be replaced or you have a leak. When you replace the shoes/pads the fluid will be pushed back into the master cylinder and fill it to the normal level. You should never have to top off any fluids. If they are getting low then you have a leak somewhere. Fluid does not just disappear(with the exception of motor oil being consumed on higher milage engines).

 

Ditto Wilber15's post unless there was not enough fluid when it was new. If you have worn pads /rotors you should not need to add fluid on a 4 wheel disc brake system. You may have a leak at the master cylinder but it should also be visible. 11,000 miles is low mileage for brakes to be that worn though. I would check all of the system.

 

so your not supposed to top off your brake fluid ?

 

There is a min. and a max line on MOST reservoirs. When you put new pads and rotors on, it should be filled to the MAX line. As the pads/shoes wear, it should go no further then the MIN line. If it gets below this, you have excessively worn pads/shoes that need replacing or you have a leak. You can top the fluid off if you want, but it will just have to be removed before you install new pads/shoes or it will spill out the top of the Reservoir.

Topping of will occur anytime you open up the brake system(such as replacing a line, hose, caliper, wheel cylinder or abs pump) due to the fact that you have to bleed the system and will lose some fluid in doing so.

 

When you replace all of your pads/linings, you should suck some fluid out of the master cyl. Then you dont risk it overflowing and making a mess. I always do this, and replace with NEW fluid. Brake fluid just loves to soak up moisture and then you get the rusty lines and brake cylinders. I guess if you had nothing else to do, you could also bleed the whole system after you do this job. I have seen some awful nasty looking fluid on vehicles brake systems over the years.

 

I agree with wilber you don't need to top off your brake fluid, low fluid is a sign of a problem low pads or a leak, at 11000 miles I'd be looking at your master cylindar leaking into your booster since you say there isn't a leak under neah any where

 

To be honest I dont think that in 11,000 miles your pads would be worn enough (even cheap pads) to the point your resovoir is low. I would attribute it to not being filled correctly at the factory.

Also not to point out the obvious, but was it on level ground and everything at the time that you had checked it?

You can probably shine a flashlight through the spokes in your wheels to see the condition of your pads. I would do that, then top it off. Monitor the level for the next few weeks and go from there.

I checked my GF's parents 06 F150 (55,000 miles) and the brakes look to be about 3/4 pad remaining. So in 11,000 miles unless you are riding them all the time they should not be worn hardly at all.