Something doesn't feel too good. For the past two months my fluid has read spot on MIN on the brake fluid reso, and within the past week my brake pedal feels to have gotten a little stiffer, and brakes slower without as much grab. Pulled all four wheels, the pads still have alot of life in them ( but I think i'm going to change the rears out because the rear ones are getting low ), and the rotors are fine with no grinds or groves in them.

What could be the issue? My bud suggest we bleed it. Trucks at 73,194 miles, bought it at 61,455 with no knowledge of any past brake work, but I do believe the dealer put new pads in.

 

Could the power booster be losing vacuum?

 

I have no idea, how would I check something like that?

 

You can check the vac lines going into the booster, both ends, and make sure all connections and hose are good, but if it is the diaphram in the booster that maybe has a hole in it, I don't know how you check it. I do know that when that happens, the brakes get very hard at the pedal. As the leak gets worse, it gradually becomes manual brakes. No power assist.

 

Ok. I hope it isn't anything that needs done by my mechanic because money is quite tight at the moment, would rather do the work myself with a friend. What would happen if I re-fill the reso a bit? Good idea or bad? And how about the thought of a brake bleed job?

I'll check out the brakes better next time. Hopefully if its this diaphram it wont be a hard replacement.

 

If you're losing vacuum you can check by following these steps:

1. Start truck let run just a minute and shut down
2. Back off the two 1/2 nuts holding Master Cylinder in place. slowly rock MC back and forth until you hear the vacuum release.
3. Tighten MC back up
4. Start truck again and let run a minute and shut down
5. Let truck sit for about an hour or two.
6. Unbolt MC again and listen for vacuum escape again. If you hear the same as before the vacuum is OK, if there is no noise or very little you have a leak.

 

It won't hurt to fill the reso. You can also bleed the brakes. Start with pass. rear then driver rear then pass front and finally driver front. If your problem is the diaphram then you'll have to replace the booster.

 

You need to keep the master cylinder full of fluid. Where did the fluid go? You do not need to bleed the brakes if the pedal is hard, only if it's mushy. That is when you have air in the lines and you bleed them to remove it.

The post above is good !

 

Thanks, I will give this a try. I am very low knowledged when it comes to this stuff, to help an idiot out, does someone have a photo of the master cylinder? And thats all I would need to do correct? I wouldn't need to tear anything else out for easier access?


I dont know whats what i'm asking, its been at MIN on the reso for the past couple months. Ok thanks.

 

Here is a pic of the MC and it shows where the fluid level should be. Make sure when you buy the brake fluid, it is the correct one. The pics also show the booster behind the MC and how it connects.
https://www.f150online.com/forums/3241020-post205.html

 

Wasn't there a TSB in regards to the brake vac booster or whatever it is called?

 

I don't know. Here is a place to search TSBs by year and model.

http://www.ford-trucks.com/tsb/tsb.php/m-FORD

 

yeah, if I remember correctly it's because the vacuum line would come loose. Have you had the recall done?

edit: nope this is only on the 05-06's so his wouldn't be effected.


2005 Ford F-150 Recall ID from NHTSA: 08V208000
Auto Recall Date: 05/07/2008
Vehicle Component: SERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUM:HOSES, LINES/PIPING, AND FITTINGS
Estimated Vehicles Affected: 605684
2005 FORD F-150 Defect Summary:
FORD IS RECALLING 605,684 MY 2005-2006 F-150 AND LINCOLN MARK LT VEHICLES EQUIPPED WITH 5.4L 3-VALVE ENGINES. THE BRAKE BOOSTER VACUUM SUPPLY HOSE ATTACHED TO THE INTAKE MANIFOLD FITTING MAY SWELL OVER TIME AND LOSE RETENTION FORCE. THIS CONDITION COULD ALLOW THE HOSE TO BECOME DETACHED FROM THE FITTING DURING AN INTAKE MANIFOLD BACKFIRE. SHOULD THE HOSE DETACH FROM THE INTAKE MANIFOLD, SEVERAL BRAKE APPLICATIONS WITH POWER ASSIST WILL BE AVAILABLE BEFORE THE VACUUM RESERVE IS DEPLETED.
Defect Consequence:
ONCE THE BRAKE BOOSTER VACUUM RESERVE IS DEPLETED, THE DRIVER WILL HAVE FOUNDATION BRAKE FUNCTION, BUT WITH INCREASED BRAKE PEDAL EFFORT. REDUCED VEHICLE BRAKING COULD LEAD TO A CRASH.
Remedy:
DEALERS WILL REPLACE A RUBBER HOSE ON THE BRAKE BOOSTER VACUUM SUPPLY TUBE ASSEMBLY. THE RECALL BEGAN ON JUNE 27, 2008. OWNERS MAY CONTACT FORD AT 1-800-392-3673.
Notes: FORD MOTOR COMPANY, 08S05




I got this from here....http://www.autobuyguide.com/ford/05-...lls/index.html

 

Ok, now I remember! It was a recall, not a TSB. I had it done to mine. It was for the connection back behind the throttle body. Could break and you would have no power brakes.

 

Ok so basically what i'm calling a reso is the master cylinder. Sounds good I will give that a try. I'll check my manual out and get the correct brake fluid.

I checked the link Bluejay gave, no TSBs for brakes on the 2004s. I know the 2005s and 2006s had a issue but I checked when I heard about that last summer and 2004s are exempt.