A brief history:

I've had the passenger side caliper replaced once since owning the truck. 2005 F150 SCREW with almost 100k on the ticker now. I've done a brake job on it twice to date and really haven't had any problems. The single caliper that was replaced was LOCKED on to the rotor... I beat the crap out of it and couldn't get it to release. Finally finangled it off and replaced it -- not a big deal to do it but, I think I have my driver's side going out now...

Here's the problem:

With less than frequent frequency, the truck, at highway speeds, will vibrate hard. It's not the 'nibble' that many of us experienced when the 04/05s were coming out... it's something way more pronounced. If I didn't know that my tires/wheels were balanced, I'd almost think that I'd lost all weight on a seriously screwed up wheel that needed a lot of lead to balance it. That's not the case here...

Again, it only does it from time to time... and, after it does it - say, on my trip from the office to the house in the afternoon at interstate speeds - I'll get home to that familiar smell of SUPER hot rotors/pads. It's almost as if the caliper isn't releasing far enough off of the rotor.

That said:

Is this the brake booster recall (that I know my truck is due for that I forgot about until doing some reading on this problem). I intend on taking it in for the recall in a last ditch effort before I smack a caliper on it but, wanted some insight...

Is this just a bad caliper? I know they can go bad but, keep in mind that the truck is kept pretty clean and I pay pretty close attention to keeping 'build up' out of the brake system (if that even matters for this instance).

Something else the problem? I really feel strongly that it's my driver's front caliper but, I can't replicate the problem all of the time and it's very intermittent for the past 2 or so months...

All feedback appreciated. Thanks, fellas!

-RP-

 

This has happened to me after adjusting the rod from the booster...for the longest time, everything is fine, then I get the same thing as you. What I think is happening is that I got the rod just a hair too far out, in that under some circumstances, the pads will rub ever so slightly that I can't feel it. Then after a while the heat will build up and the pads and rotor will get hot enough that they begin to expand and bind, and the process just continues. I have also had that 'heart stopping' vibration. My solution was to 'ever so slightly' back off the rod from the booster. Problem stopped and never came back. Something to look at anyway.......

 

Thanks, Sam. It's really curious...

I went home last night and pulled out my impact and pulled the wheel. The wheel was so hot, I could barely handle it... not to mention the caliper/rotor.

I let it cool down and pulled it all apart. I nearly couldn't get the caliper off of the rotor... had to beat on it to get it to slide off.

The pads look great... the rotor doesn't look bad either (they're originals). The inner has a bit more wear but, mind you, it's nearly 100k worth of wear -- mainly highway though.

Put it all back together and drove it in this morning (about 25 miles, one way, to work) in stop-and-go traffic. ZERO problems this morning. Everything was cool to the touch and seemed fine. I guess we'll see if it does it again this afternoon....

I hate gremlin problems. Either break or work right... hahaha...

Thanks for the tip on the rod though... I may give that a look tonight if I can figure it out. Any chance this could be related to that brake booster recall?

 

hmmm... the exact thing I warned about on that thread and got abused for saying it... I wonder how many more people will have the same problem...

nope - nothing to do with the brake booster recall for a leaking vacuum hose (this is the recall you are referencing, right?) A vacuum leak will not apply the booster.

It sounds like your brake is definitely dragging. Now you just have to figure out why. Have you done the booster output rod adjustment too? If not, then maybe its an issue with your sliders hanging up? Did you clean and grease them while you had it apart?

 

I was going to say, check the sliders or slide pins. Mine were are rusted and the outer pad on the passenger side was compacted. If you get a chance Brad, pull the caliper off and see if it slides easily.

 

Ive had my both my caliper's changed now on mine because to the random sticking. Both of them were from the piston breaking/chipping and not allowing the piston to retract after the brakes were applied

This one was the worse out of the 2 but you can see the boot is torn on the top have causing the piston to bind and not retract

 

I've never tweaked the rod... The slides did move pretty freely when I had it off last night but, I probably should've spent the extra time and cleaned/greased -- I didn't do that but will tonight.

Just to make sure I'm on the same page with you guys... when you all say 'slides', you're referring to the two bolts that hold the caliper on, correct?

Yeowch. That'd chew through a rotor. Mine definitely isn't in that boat but, it's plain to see why yours wasn't working... ouch, man!

 

Thanks, guys!!

 

mkosu04 is correct. It' can not be the recall hose.

 

Didn't think so... I still should have it done though.... I know my truck was in the recall campaign. Thanks.

 

Yep, one of these days when you mash on the brakes, the pedal may be hard as a rock and not be doing a lot of stopping.

 

Brad,

These are the slide pins as you thought:



These slide clips rusted on mine, and that is what the pad moves on when the brake is applied and the piston compresses.



Now I was talking to the head mechanic/manager of the garage at my University today and I was asking him about doing work on my truck. He had said the Ford's are notorious for having issues with their braking systems. JBrew has made numerous comments saying how they are not up to par with the trucks size and weight like they are on the SD's. I'm not sure of the recall that was discussed in previous posts above me, but there are weak points in the brake lines and the head mechanic actually mentioned that today. The line can kink or get damaged and cause similar things to what you are seeing being the caliper is not able to release fast enough. He said he does not change a caliper without changing the portion of the brake line that goes to is just as an extra precaution. One other thing that I have learned is that brake hoses may look ok, but be internally damaged. Definitely give the slide pins a good wipe down and put some grease on there. This I believe is what is recommended:



The slide pins should be able to easily move in and out when you pull/ push on them.

 

couple things as food for thought.

in general if its vibration you feel through the steering wheel its front axle, if its in the seat/floor its usually rear axle.

if its intermittent, try doing a good thorough brake flush. If you have moisture in the brake system, after a few stops, or sometimes just once the engine gets up to temp, the fluid will boil (expand) and cause brakes to be applied/drag.

good cheap caliper slide grease we use at work is dielectric grease

 

Or go to NAPA and get a tube of Sil-Glyde.

 

It usually takes more than engine heat and a few normal stops to boil brake fluid, no matter how much moisture is in it. Generally you have to be racing (not likely in a truck) or riding the brakes down a mountain.

Anyway, if you do boil your fluid... your brake system will accommodate. The fluid will just get pushed back into the master cylinder reservoir (unless of course you have adjusted your booster output rod such that the comp holes are blocked off by the seals). You don't even need to boil the fluid - just the thermodynamic expansion of the fluid in the calipers will be enough to apply the brakes if your booster rod has been adjusted out too far. (this is a fact - we've done the test, I've seen the data)

You would know right away if you boiled your fluid... on your next apply your brake pedal would go to the floor.

But still - a brake fluid flush could be helpful if you have contamination in your lines. Perhaps contamination is "trapping" pressure in your caliper by clogging the orifice where the flex line hooks up? (just a guess on my part)

I've also heard it stated that the flex line can trap pressure if it is failing. I do not understand it, and have never been given a clear explanation of how it happens. But some people will insist it happens and that they've seen it. So if you are going to bleed perhaps it would be a good time to put on some SS Flex lines?