Question Brake spongey

[Rio_Grande]

I have a 99 F 250 Superduty, Recently the break peddel has to be depressed much farther than usual to get a response. I also notice that the bottom of the peddel is much spongier that I recall.

Brake pads are in good shape and rotors are within spec. No obvious signs of leaks or loss of fluid.

Any Ideas??

 

[JLDickmon]

most likely, you have a caliper that is stuck on one of the slide pins..
you're stepping on the pedal, but instead of applying pressure to the pads, you're swinging the caliper on the pin that's sticking...

 

[rammertide07]

While driving it down the road, try punching the brake real fast. If it stops better then, your problem is the master cylinder...just behind the steering wheel in the engine compartment. The reason it would respond better, when punching the brake, is that the seal is cupped. If the seal is bad it will allow brake fluid to pass around it. But if you punch it, it cuases the "cup" to open up and create a good seal.

 

[aklim]

Could it be a bad hose? If the hose bulges, it reduces the pressure. I changed only the hoses and the pedal stiffened up quite a bit. Could also be the brake fluid flush that helps some.

 

[dale7637]

I am onside with the caliper pins, we have a ton of trouble with them. The pins are out in the open, and it seems that as soon as the truck spends some time on gravel the seals get trashed and the pins seize. Easy fix, you can buy the pin and seal kit direct from ford. On my trucks i have used some heavy guage tin and bent a guard to protect the pins from gravel damage. I can post pics if interested.

 

[Rio_Grande]

Yes dale I wuld be interested in that.

It sounds like it could be several things but the most likely for my truck is the pins, I had 2 last brake change that had to be broken free, and I remember then thinking I needed to replace those before i had issues with them. I bet that is the problem.
If not I will follow up with the other Ideas.

The ability to stop or feel dosent change but I will try the stomping idea and see anyway..

Hopefully I will be able to get it into the shop tomorrow and get some heat on it to check the pins. That would be a good solution as it would be cheap

 

[JLDickmon]

Could it be a bad hose? If the hose bulges, it reduces the pressure. I changed only the hoses and the pedal stiffened up quite a bit. Could also be the brake fluid flush that helps some.

I have seen it, but it's not as common as the pins in the caliper bridge seizing up

 

[aklim]

I have seen it, but it's not as common as the pins in the caliper bridge seizing up

I know it isn't but you already got the caliper pins idea. Another thing could be that it needs a brake fluid flush because somehow it got air in the system

 

[iracemine]

the hole the pins slide in get just as nasty as the pins. what do you guys use to hone out the hole???

last time I used a dremel wheel and that deff did not do the trick. does snap on or someone like that make a small hone bit?

 

[aklim]

I wouldn't. I'd use some Emory cloth and scrub it out but I am afraid of honing it too far and making it like throwing a hot dog down the hallway.