brake pedal kick back

[Peroni]

97 F Superduty, I replaced the entire braking system due to rust and previous owner neglect/abuse. PS pump, hydro booster, master, rabs valve plus the load control valves on suspension are all Motorcraft replacements. Using Schaeffers All Trans in the ps pump.

Worked fine for about a year but has suddenly developed a kick back at the brake pedal. Does this about 20% of the time. Sometimes it's right when I step on the pedal. Other times it happens when I've already pushed the pedal down but not enough to start stopping the truck yet.

I've read this could be due to contaminated fluid so I thoroughly flushed the system. Fluid that came out looked and smelled just as new as the stuff going in. Didn't change a thing. Everything is tight, no leaks anywhere. It just started happening one day. Still stops fine though. Could the hydro boost unit be failing causing this problem?

 

[glovemeister]

Ever see TSB # 99-25-8? Its on another forum and not sure I can link to it.

 

[Zmann]

link it

 

[Zmann]

here it is it's a pdf http://www.google.com/url?sa=t&rct=...SRK8scilOA8c278Vg&sig2=o8bcRSygsrnGaCCqpepiNA

 

[Peroni]

Ever see TSB # 99-25-8? Its on another forum and not sure I can link to it.

Yes that is the procedure I followed and it didn't do anything at all. My brakes do not grab, there is no hissing or moaning. I just get that kick back at the pedal.

 

[Zmann]

i get it every great once in a while and always have

sometimes when I take off and if I have to brake / sometimes when I have to brake fast and stomp the pedal

it kicks back and almost feels like a fast pulsation in the pedal that I don't think is an ABS modulation

 

[gnxtc2]

Could you take a pic of the load control valve on the rear? When you replaced the rear valve, does it come complete or do I have to go to a dealer or junkyard to get additional parts?

I want to adapt the load valve to my truck with the hydro conversion

Thanks

Billy T.
[email protected]

Sent from my DROID BIONIC using Tapatalk

 

[Peroni]

Could you take a pic of the load control valve on the rear? When you replaced the rear valve, does it come complete or do I have to go to a dealer or junkyard to get additional parts? I want to adapt the load valve to my truck with the hydro conversion

Billy this link shows everything in pretty good detail. You will need other parts besides the valve. I believe the valve part # was E5TZ-2B547-B. Beware as it is obsolete and the few places that have them have high prices. Mine set me back $250!

IMHO it's not worth it to retrofit. My OBS F Superduty and F350 have pretty much the same braking system except for that valve. Taking the same route with the same 16K GN horse trailer in tow I didn't notice one bit of difference in braking between the two trucks.

i get it every great once in a while and always have

That's my whole issue Zmann the truck never did it before - never. Have had the same pump, booster and master on my F350 for years and it has never and still never kicks back at me. The F Superduty never did until suddenly one day it just starts doing it. That right there tells me something has to be wrong. I suspect the booster but do not want to throw parts at it randomly. Might end up swapping the booster in the F350 to see if the problem follows.

 

[Zmann]

man that looks overcomplicated I can see why they don't use them

did u see the part about replacing it if the arm is taken off and it looses index? and then the complications of adding a lift kit?