Just replaced the front rotors and pads. The old ones were so worn out ( no sequel indicator on old ones. ) Put power stops on the front because I pull a 24 foot pontoon. When I come to a full stop I can push a little harder and it feels like a sponge . Had this with the old ones to. They feel all right when stopping, this only happens at a full stop. The new rotors are broke in, during the break in period they worked just fine. This returned after they were seated. my question is is this a master cylinder or some else is wrong ?

 

what vehicle? does it have hydroboost assist or a vacuum booster?

 

1997 chevy tahoe 5.7 4 wheel drive, looks like vacuum boost.

 

if the pedal is spongy and deep; try pumping the pedal. if it firms up and is not as deep, there may be air in the system.


does this occur only when towing? If yes, how heavy is the load and is the trailer equipped with electric brakes?

 

How's the truck while towing?

 

This is all the time, whither I am towing or not.. It does not get better by pumping them. No brake fluid loss. They get soft after I come to a stop. They hold good and there seems to be no problem slowing down. The anti lock even kicks in when I get hard on them. Tried that to see it was working. The 24 foot pontoon does not seem to have any effect on the braking . Also it does not have brakes on it.

 

Completely bleed the braking system using quality synthetic DOT-appropriate brake fluid. This should be a rule of thumb for any brake job. If you do not feel an improvement in pedal feel, the master cylinder may be failing. Also check the vacuum hoses used to boost the brakes for any leaks. A side question - do you have standard or oversized tires mounted??

 

be very careful with that synthetic word, DO NOT put dot 5 fluid in your vehicle


That era and system of vehicle are pretty well known for having pedal feel issues after brake work was done, without feeling it myself I can't really give an opinion if theres actually an issue or not. My thought would be to check your pedal travel and see if its within spec. or not and do a good bleed on the system to be safe.


I've seen numerous times where a brake job or repair was done and the vehicle ends up with basically a completely new system and the pedal still feels the same. Never have found out why those vehicles were that way.

 

he stated pumping the pedal did not firm anything up...indicating there is no air in the system... the symptoms do not suggest moisture contaminated fluid boiling from high temps...what good would bleeding do? there is no need to bleed brakes at every brake job. 2 years is the industry standard but that is a upsell profit machine. If the system wasn't opened during the brake service; that should not be the problem.
this all started after replacing pads and rotors correct?
it could be a bad master, flex lines bulging, organic brake pad feel or even the load from the trailer(who knows how much it weights).

 

Sorry, I left out some info. No the problem was there before I changed the rotors and pads. The system was NOT opened during the changing of them. If I get on them hard they work just fine and they work like they are suppose to when stopping normal. This condition is only after I come to a complete stop. Well recheck all the lines and let you know. The tires size and manufacture is Fuzion 255/70R16.