Brake Issue.

[MrGearhead]

The brakes on my ‘06 (2wd) are acting up. I did rotors, pads, drums, wheel cylinders & hardware. Normal driving is fine but if you try to stop quick, the pedal drops to the floor. You feel and hear the slight sound of the ABS noise and pedal vibration for a sec. No brake light, no leaks, no loss of fluid in the master. I’m guessing the master is bad but I’m afraid it’s the booster.
I only drive this truck 4 or 5 times a month and the problem wasn’t constant. But driving it home a week ago it kept happening. All I thought was.. “Time to trade it”. I had a week to calm down. Lol

 

[Bronco ii Man]

Kinda sounds like a master cylinder problem. No leaks external that you can see but leaking inside itself. Had it happen on my Bii.

 

[Uncle Gump]

I'm pretty sure it's your ABS going off... and I've have some issue with the front wheel speed sensors.

Tell me... does it tend to wanna pull the truck left or right when it happens?

These wheel speed sensors tend to fall off when at slow speeds... but the others say it's still moving so ABS tends to unapply whatever speed sensor falls off.

 

[Bronco ii Man]

Press the brake a few times to get a full pedal and then press hard on it! If it holds a few seconds and slowly goes to the floor your master cylinder is bad! Booster will 90% of the time cause a vacuum leak! Thus causing a high idle situation! I’m sure you got all the air out when you bleed the system? Could be the culprit? Couple of things to look for.

 

[MrGearhead]

Yea. I’m just a crabby old man now .. lol. I’ve been wrenching for over 35yrs and after a 50hr week of fixing people cars, the last thing I want to do is work on my own junk anymore.
I’ll have to pick up a new master.

 

[MrGearhead]

I'm pretty sure it's your ABS going off... and I've have some issue with the front wheel speed sensors.

Tell me... does it tend to wanna pull the truck left or right when it happens?

These wheel speed sensors tend to fall off when at slow speeds... but the others say it's still moving so ABS tends to unapply whatever speed sensor falls off.

Yea but I’m not getting an ABS light. This is my issue with an “older” truck. I’m tired of chasing issues.

 

[MrGearhead]

Press the brake a few times to get a full pedal and then press hard on it! If it holds a few seconds and slowly goes to the floor your master cylinder is bad! Booster will 90% of the time cause a vacuum leak! Thus causing a high idle situation! I’m sure you got all the air out when you bleed the system? Could be the culprit? Couple of things to look for.

It stays hard. It only drops out when driving and a slightly aggressive braking.

 

[Uncle Gump]

Yea but I’m not getting an ABS light. This is my issue with an “older” truck. I’m tired of chasing issues.

You won't get a light... it's working as it should.

Does it pull one way or the other?

 

[Uncle Gump]

Yea but I’m not getting an ABS light. This is my issue with an “older” truck. I’m tired of chasing issues.

You won't get a light... it's working as it should.

Does it pull one way or the other?

 

[MrGearhead]

You won't get a light... it's working as it should.

Does it pull one way or the other?

No. It doesn’t pull at all.

 

[Uncle Gump]

Then it could be the rear sensor. If it pulled... it would be easy to tell what sensor went bad.

I would look at wheel speed data... or have someone with a tool look.

I guess I should have asked the obvious.... you don't have a wheel locking up... do you?

 

[MrGearhead]

Then it could be the rear sensor. If it pulled... it would be easy to tell what sensor went bad.

I would look at wheel speed data... or have someone with a tool look.

I guess I should have asked the obvious.... you don't have a wheel locking up... do you?

No lock up. I have a Snap-on Apollo at the shop. I’ll have to take it for a quick ride.

 

[Bronco ii Man]

Weird no lights, no pulling, and only goes to the floor on hard braking! Got a gremlin somewhere lol!

 

[MrGearhead]

Weird no lights, no pulling, and only goes to the floor on hard braking! Got a gremlin somewhere lol!

Yep… I hate chasing gremlins now.
I need to get off my ass and finish the project.

 

[Ranger850]

Same truck???