OK....so we put new rotors and pads on the little brothers truck the other day. Few days later, when he's slowing down at low rpms with brakes applied, at almost 'stop', the pedal drops and pulsates. It does it intermittantly. And I notice that it only occurs after driving around for a little bit. It wont do it at say, for example, start it up in the morinng and go around the 1mile loop around the house.


He has no visible or feelable vacuum leaks at the booster. I wanna say it's a vacuum issue...but i havn't a clue.

HELP!!

Shane

 

Specs on the truck?

 

did you even look at the backs?


check valve on the booster...


or maybe master

 

2001 2wd 2.5L 5sp

 

I had something similar happen on my '95. I had to do with the ABS sensor.

 

Mine does this ALL the time, so freaking annoying. Tech said I have a bad seal on the right front caliper since it pulls to the left when I brake...thats all they could come up with besides air in the line somewere.

 

All front seals are new, new inner and outer bearings, new rotors, new pads, new grease of course packed into those new bearings. Also we just greased the caliper sliders and pins. About to go test drive the truck after I check out the rear.



I've NEVER had any issues on ANY of my past 6 rigs showing this symptom and it being the master...ive changed masters on all my past vehicles but my ranger. This truck i'm working on only has 49k on it. Gonna go check out the rears. I'm finding nothing online showing the symptoms we're getting.

 

Shane try re bleeding the whole system. Sounds dumb but worth a shot. Furthest to closest away from the master.

 

OH YEAH...forgot to add...while we greased those pins, we also bled the system.

 

Does it feel like someone is jamming a screwdriver into the wheel as you're coming to a stop?

 

When my truck did that upon buying it it was because the two back break calipers were frozen.

 

factory discs on a ranger? what? lol. I knew what you meant though.

 

Most likely an ABS sensor.
Thinking back, my sport trac did this every now and then after I let someone replace the front pinion seal and he didn't put thing together right (lost caliper bolt and lugnuts).
Doubt that you did anything wrong, but it sounds like an abs sensor problem. RABS or 4WABS?

 

Okay guys, this is my truck....finally getting on here.


Just drove it around after cleaning the front abs sensors and having bleed the system and greased the sliders.


It still does it!!! argggg.

I noticed it does it only under 'normal' or 'light' breaking conditions. If i hit the brakes harder than 'normal' it doesn't do it. Interesting.....

Going to clean the rear ABS sensors tomorrow morning. Hopefully it fixes it, else Shane is going to take it into Ford when i leave for college, dammit....

 

So it's like the ABS kicks on for a split second? Because mine just started doing that after I got my rotors turned and installed new brake pads. We cleaned the ABS sensors right before we put the rotors back on too.

If you figure it out, let me know! It bugs the crap out of me and almost caused me to hit a car when pulling into a parking spot the other day.

 

That's exactly what my sport trac would do occasionally. I guess I didn't think much of it since I had just re-geared and put the aussie locker up front.
But it was normally pulling into a parking spot, just light breaking right before you stop, and the ABS kicks in. Feels exactly like hitting the brakes on ice.
There is no question about it, it IS the ABS. But I'm not sure exactly what causes it. I think you can disable the ABS by pulling one of the fuses, without screwing anything else up. Might be worth finding out and pulling the fuse if you need to confirm what is causing it (I never did like ABS anyway).

 

It feels like ABS kind of. No ABS dummy lights up on the dash ever. And it only happens sometimes. I'm cleaning the rear sensors tomorrow and hopefully it fixes it. I'll try pulling the fuse too if cleaning the sensor doesn't work. dam truck.

 

..and dam Marie you know me so well

 

I had the same problem with my truck and it ended up being the abs pickup ring on the rotors that i had. I ended up pulling the abs fuse until i got new rotors and now everything is perfect.

 

EXACTLY what it feels like. I tried to say that...but that statement totally put it perfectly.








Now...these are new Stoptech rotors and they do have the ABS 'grille' thing on the backside of the rotor.



OH! Forgot to add......there's a 'hissing' sound coming from the firewall area when it happens.

If all else fails, i'll be calling up my buddys at the dealerships and shops. I'm dumbfounded as to what it is.

 

I am betting that you do not have the correct torque on the spindle nut and the bearings are sloppy because of this. When you brake hard it will not do it because your calipers will lock up the disc in a straight plane. When you brake slightly your disc is wobbling because the nut is not tight enough and the ABS is kicking in because it is reading a wobbling Tone Ring.

 

Proper torquing was performed first by my brother, then repeted by myself to check his work. 15-20 ft lbs to set the inner bearing. back off 1/2 turn, then 20ish inch pounds. Did it using the Ford factory books and Haynes/Chilton book. They spin properly when the pads aren't dragging on the disc.

 

OK, in that case you have a damaged or incorrect tone ring on one or both of the rotors.

 

Are the tone rings replaceable?? Like replace the rings that are on the current rotors on the truck, and use the stock rings?

 

I think it depends on the rotors themselves. I believe some rotors will allow ring replacement (such as stock rotors). I say this because I have seen the tone rings available from Ford. They are also referred to as "ABS Exciter Rings".

Unfortunately, you will have to take off one of the rotors and look at it to determine if the tone ring is replaceable.