08 f250 6.4 brake pedal feel

RyanG · June 2, 2015

anybody run into customer complaining about brake pedal feel on 6.4 trucks? customer says he has

to push pedal almost all the way to the floor to get truck to stop( in my opinion he is being a little dramatic).

checked everything out, didn't see any obvious problems, drove truck, feels like a super duty to me. I can get abs activation on dry pavement. this

is the second 6.4 customer in a year that I have had complaining about brake pedal feel and myself and

another tech cant find any issue. another tech mentioned something about a possible old tsb for this

issue but cant find anything in pts.

lmorris · June 2, 2015

Any customer we have with this complaint is usually new to the Superduty scene and is not accustom to the "fade".

the_twig_187 · June 3, 2015

yup had one myself not long ago. was a 6.4 also. the brake pedal travels a lot more compared to cars or earlier model trucks. even though the pedal has more travel distance, the vehicle stops dead long before the pedal reaches the bottom of its travel. people are used to the rock hard pedal with minor travel and the 6.4 and the 6.7 are simply not the same as what they are used to. but try explaining that to a customer

Matt Saunoras · June 3, 2015

Always check the studs holding the master to the hydroboost. I had one break one time on a 6.0. Went all over that thing twice before I found it.

Same goes for how many cab off repairs are done on 6.4s, it wouldn't be hard to leave a nut loose.

YukonTyler · June 4, 2015

A little while back I had one with an intermittent soft pedal - found the hydroboost leaking between the booster and the master but not enough to actually leaks a stained trail of fluid. Fluid wasn't aerated, either. Worth a quick look.

RyanG · June 8, 2015

checked over everything and found nothing, thought about throwing a master cylinder on to see if there was a difference but I dont

want the guy thinking I'm admitting there is an issue because then I own it. explained to the customer about

the pedal feel but I'm sure he thought I didn't know what I was talking about and took it somewhere else.

jimmy57 · June 8, 2015

WIth 4 wheel disc brakes and some anomalies of the hydraulic modulator giving some odd pedal feel when nothing is wrong I have started doing blocking plugs on master cylinders to check them. I have ends from lines that I cut and weld to seal. Stick those on and then push pedal and see if the pedal goes down. If it is solid then master cylinder can be eliminated.

the_twig_187 · June 8, 2015

I have started doing the exact same thing (sealing off brake line fittings to make master cylinder plugs) then just have someone apply the brake pedal. if it is hard as a rock and wont go down then the master is ruled out. if it sinks to the ground and no fluid is seen leaking from the plugs then a cup seal inside the master has rolled over and is causing your poor pedal.

the kicker is I used this method on a 2000 E-350 that had a crap pedal and confirmed that it WAS in fact the master cylinder that was bad and thus swapped the master with confidence and fully repaired the vehicle.

Matt Saunoras · June 9, 2015

It seems like every one I've put a hydroboost unit in for an external leak has awesome pedal feel after I'm done. :scratch: Never put 2 and 2 together because no one has ever complained about it.