Brake pedal looses 1/2 the resistance at a stop. (1 Viewer)

[IslandJ]

On the way home today in the 60 I started smelling what I thought was a burning clutch or brake smell on the freeway.
Stop and go traffic in LA and chopped it up to some one in front of me. After a few blocks on the surface streets I noticed the brake pedal went half way to the floor, further than usual when braking. I quickly double pumped it and braked as normal till we came to a stop.
While at the light I noticed the pedal get soft, loose pressure till about half way to the floor then level out.
It held there for say 10 seconds then started loosing pressure ever so slightly.
I popped the hood and looked under the truck and didnt notice any visible leaks but obviously there is a leak some where , right?
Any and all suggestions welcome.

thanks,
Jason

 

[NeverGiveUpYota]

Maybe a piston is catching? Have you done any brake work recently? Any fluid behind the clutch pedal against the inner firewall?

 

[Freewheel]

Check all your wheels for brake leaks- If there is no visible leak anywhere, it sounds like your master cylinder may need to be replaced. It can die without leaking externally - the internal piston seals fail and it just sloshes fluid around without being able to hold pressure.

 

[IslandJ]

Maybe a piston is catching? Have you done any brake work recently? Any fluid behind the clutch pedal against the inner firewall?

No, no brake work recently... thats the biggest issue. HA. Besides new fluid a year ago its the same parts that were on the rig a year ago when it came out of a 15 year hibernation.

Check all your wheels for brake leaks- If there is no visible leak anywhere, it sounds like your master cylinder may need to be replaced. It can die without leaking externally - the internal piston seals fail and it just sloshes fluid around without being able to hold pressure.

No visible leaks. Ill look into the the Master cylinder. THANKS

 

[mattressking]

No, no brake work recently... thats the biggest issue. HA. Besides new fluid a year ago its the same parts that were on the rig a year ago when it came out of a 15 year hibernation.


No visible leaks. Ill look into the the Master cylinder. THANKS

I'm going more with @NeverGiveUpYota

If you smell burning, that means a pad is hanging up or excessive riding of the brake pedal. I'd lift the truck up on all fours and bleed all corners if no leaks are visible after inspecting the lines/calipers front to back then continue driving and see. A leaking line usually means a pedal that won't hold pressure, not one that hangs up and causes a burning smell.

In my mind, if you smell burning and the pedal has a longer stroke/softer feel than usual, a piston has hung up and more fluid is being pushed into that cavity hence the change in pedal feel.

 

[NeverGiveUpYota]

Honestly just looking around the backside of the tire can show you if a piston is locking up too. They’re very visible and obvious. Before I did my front brakes I could feel them dragging and upon visual inspection the pistons were fully ejected from the calipers. The rubber boots were completely visible because my pads were down to basically nothing but the backing plates.

 

[Randy88FJ62]

Bring it over to my house and we can take a look at the brakes.

-LA Country Trailcrew 4x4's

 

[NeverGiveUpYota]

There you go @Jasonredwood! ^^^ lucky you!

 

[IslandJ]

Very kind of you @Randy88FJ62
I just shot you a message. Thanks all.