Caliper Knocking...

[Creager]

Hey guys.

Since i've owned the truck my front brakes have made this Click/knock noise when i initially depress and release the brake petal. Originally it was a very soft, click, when i would just bearly push the petal.

Now with new calipers, rotors, pads, bearings... the click is LOUDER and i can hear it when i take my foot off the petal also.

The brakes work great otherwise, kind of confused.

I thought it might have been the little shim that goes behind the inside pad. Initially i didnt reinstall them with the new pads and new calipers, but i went back last weekend and put them in. No difference?

 

[jimbo74]

is your rotor loose? my truck soemtimes clunks up front... on my yota it is from the UCA crossshaft loosening.... i know, totally differtn than a first gen x though

 

[Longjohn119]

How are your radius arm bushings? When worn bad they tend to thunk on braking and again when you let off ,,,

 

[410Fortune]

I agree sounds like radius arm bushings, ball joints, or if it is the brakes then it is time for new caliper slide pins........

Visual inspection is whats needed. A shakedown should be done, this means put the questioned wheel up in the air, support the FRAME with jackstands and start looking for anything loose, check the tire movement for looseness in the ball joints, check the caliper mounting, if the slide pins are original, you need new ones, if they press out really ewasy thenits likely they are shot.

Check the condition of the nylon ring on the rear side of the radius arm bushings, check the rubber bushings and metal crossmember.

Anybody who knows what radius arm bushings sound like when they go bad can spot it right away, it will sound like a clank on the floor board just below your feet, when you stop or accelerate..

 

[Creager]

Well no, its not radius arm bushings (its more of a mechanical sound), ahah its easy to tell when those things go bad... The ones in there now are polyurathane and are pretty new (january), i did greased them with some lithium grease this weekend (pressed in new Axle pivot's), i noticed no chunks taken out of them.

The slide pins are new and lightly greased.

Ball joints were replaced with the RAB's back in january. No excessive up-down movement when the truck is on stands.

This problem can happen with the engine not running, stopped in the driveway. I noticed yesterday its actually not comming from the calipers... interesting. While i was bleeding the brakes i could hear the noise and it sounded like it was comming from upstream under the hood (?)... Its only when i initially press the brake and when i take my foot off the brake, it kind of sounds like a valve clicking

ABS booster?

 

[410Fortune]

Say what now? Check the torque on your sway bar...
Check the coil spring to make sure they are seated completely and locked in place

You think its a valve opening/closing?

Could be ALOT of things, steering shaft u joint, axleshaft,

If you recently replaced the axle pivot bushings and the noise is worse, check to see that the beam is still seated on teh bushing, they are a real press fit from Ford and when the new bushings are put in the beam can move forward ad back, I tack weld them to the beam now because of this.

Check the engine mounts.
If equipped, check that stupid shock absorber on the drivers side engine mount, check the trans mount, check the sway bar bushings, tie rod ends, shakedown test.

Also check the torque on the pitman arm nut.

I have seen it all!

My conclusion is the TTB makes noise, no matter how much $$$ you throw at it, the beams move around, the radius arm bushings give a little, and well they just make noise.

 

[Creager]

yeah...

The TTB rides GREAT right now, esspecially after i pressed in my Axle pivot bushings in the RIGHT way this time . no excessive noises or anything... (the problem i was having before that i suspected to be the axle pivot bushings is gone since i fixed them, this is a totally seperate issue)

my problem is soley somewhere in the braking system... no turning of the wheel, no bouncing of the suspention, motor off... Like i said i can be stopped in the garage and its only when i tap the brake petal. its hard to explain, i dont even have to actually apply the brakes. Just a light tap, on and off the brake (in the first 1/2 of an inch of travel in the brake petal) makes the noise. I cant see that translating to be anything suspention related

it it helps my BRAKE LIGHT and REAR ANTI-LOCK lights are stuck on. But i almost think the lights and my issue are not related.

Ford put a shock absorber on the engine mount? ahah i havent seen that yet.

 

[410Fortune]

if the lights are on check out the master cyl and related parts, wiring, etc.
Pull the ABS codes.

I suspect you have a bad ABS valve, or your master cyl is toast, but normally the brakes would not work so well if this was the case....

does it have RABS or full ABS? 92 was a crossover year for the ABS system.

Considering when you push on the brake pedal the following happens:
plunger on pedal pushes through booster, vacuum booster uses bladder to add pressure to plunger
Plunger enters master cyl and depresses hydro plunger, with O rings and chambers.
Hydro fluid leaves master and fills calipers, etc etc...

So unless the master cylinder O rings are leaking, or the bladder in the booster is ripped I would not suspect them as cause for the noise.
Does the booster hold vacuum?
master leak fluid?

depending on your ABS, youeither have the 4 way valve right there on the frame rail or you have the RABS vavle back above the rear axle.

I hate those damn valves, I am not to fond of the ABS on these trucks either, I can pump my own brakes.

 

[Creager]

if the lights are on check out the master cyl and related parts, wiring, etc.
Pull the ABS codes.

I suspect you have a bad ABS valve, or your master cyl is toast, but normally the brakes would not work so well if this was the case....

does it have RABS or full ABS? 92 was a crossover year for the ABS system.

thats a good question. I would imagin its RABS. The build date stamped on the truck is NOV-11-1991. The rear has a small sensor (above the pinion) which plugs in, the sensor goes to the little ring pressed around the carrier. The front has no wiring. and the front locks up in the mud would the RABS valve be that little block the metal brake line flanges screw into?

Considering when you push on the brake pedal the following happens:
plunger on pedal pushes through booster, vacuum booster uses bladder to add pressure to plunger
Plunger enters master cyl and depresses hydro plunger, with O rings and chambers.
Hydro fluid leaves master and fills calipers, etc etc...

So unless the master cylinder O rings are leaking, or the bladder in the booster is ripped I would not suspect them as cause for the noise.
Does the booster hold vacuum?
master leak fluid?

No obvious vacuum or fluid leaks... hrmm

Too add to the equation, the rear brakes have been given me trouble latley. The emergence brake bearly works, but that has nothing to do with RABS, so i imagin this is another issue. I havent had time to visually inspect them, but when i had the drums off two weekends ago, the pads had plenty of meat on them and the adjusters were in the same spot they always been. i adjusted them out a half turn for good measure.

Braking performace as a whole has decreased.

looks like i need to get busy.

 

[410Fortune]

master cylinder possibly old or bottomed out.....

 

[Creager]

Thanks for your Help man, i knew this would be a 410 question

 

[Rhett]

thats a good question. I would imagin its RABS. The build date stamped on the truck is NOV-11-1991.

99% sure your truck is RABS only..if you have no wiring, tone ring, or sensors in the front then for sure it's RABS.

Braking performace as a whole has decreased.
looks like i need to get busy.

I read your whole thread, and yeah, radius arm bushings was the first thing I thought. One thing I have found, that isn't mentioned in this thread, is that some poly bushings can make LOTS of noise even when new, and some are quieter.

I have seen vac leaks in the master cyl. cause the problems you describe...
if you're getting worse braking performance there might be some leakage in there. Noise, too. My friends 93 XLT has a "farting bladder" which I can't quite pin down but I think it's around the bb (brake booster) or master cyl...

 

[410Fortune]

the booster has a bladder and is a vacuum booster, the master cylinder is completely hydraulic and uses no vacuum.

The RABS module is a POS, you can remove it and all the wiring and everything that goes along with it, I did years ago. It required a simple adapter to go from the input brake line to the output bake line (to the rear axle)

Its not any bushings cuz he said he can make the sound when the car is sitting still, not even running.

 

[Creager]

I read your whole thread, and yeah, radius arm bushings was the first thing I thought. One thing I have found, that isn't mentioned in this thread, is that some poly bushings can make LOTS of noise even when new, and some are quieter.

Yeah i agree with that, The poly-ones definatly make more noise then regular urathane. But the front end just feels so much tighter than with the rubber ones. I also had to replace my RAB's once a year with the rubber ones... the noises would always come back within 6-8 months of replacement. I think the poly urathane stuff is really going to last.

I have seen vac leaks in the master cyl. cause the problems you describe...
if you're getting worse braking performance there might be some leakage in there. Noise, too. My friends 93 XLT has a "farting bladder" which I can't quite pin down but I think it's around the bb (brake booster) or master cyl...

im going to try and lisson to it more tonight if i get a chance. im also going to try flushing the system and see if i can restore some braking power

The RABS module is a POS, you can remove it and all the wiring and everything that goes along with it, I did years ago. It required a simple adapter to go from the input brake line to the output bake line (to the rear axle)

Dude i like this idea. A LOT. **** the rear brakes lock up more then front brakes! i like being able to lock them up going 60 if i have to, it just feels safer.. i guess ill do a search on removing RABS to find out what that coupler thing i need is

Its not any bushings cuz he said he can make the sound when the car is sitting still, not even running.

Yep, thats correct. im gonna try and see if i can really pin-point this issue tonight, if i can get some time away from the girl

 

[Longjohn119]

Speaking of brakes and bypassing the RABS, who the hell designed the master cylinder on this thing? It uses an oddball size fitting and a European (reverse) flare but uses the standard double flare everywhere else .... it's like some Marketing 'Genius' or Bean Counter just threw on the cheapest master cylinder they could get as an afterthought after the rest of the system was already designed ...

Some days I could just "go postal' on some design engineers .... or at least make them work on their own poor designs ...

 

[410Fortune]

Hello and welcome to Ford.
You have no idea what I went through when I did the rear disc brake conversion complete with 95 Explorer master cylinder and brake booster.

They used standard metal lines along the frame rails, but a metric bubble flare at the master, and I believe to the input on the 4wabs module.

I had to run new hard line from the master to the rear axle hard line, at the RABS module on the early models (like my 88 BII) it was metric to the axle.

I found an adapter that completely replaced the RABS module and connected the two flared fittings. I can get a picture.

the problem is the drivetrain is Merkur and the frame is USA, then when they went to the 4WABS from the RABS they really got crazy and took the standard fittings out of the braking system....

The RABS module never did work right on my BII< if it was working right then it scared the crap out of me because I could brake the truck better on my own. that sucker would kick on and the truck would get sideways on just damp roads....
It might be better on the heavier Explorer but on a truck like mine I prefer no ABS

If your rear tires lock up too easy, or are not doing enough braking you should know that the front/rear biast is slightly adjustable, the tip of the plunger that comes into the master from the booster is adjustable, turning it will adjust the biast. The process is kinda a PITA when you do it like me, adjust, drive, adjust, etc...but once its dialed in its great. My rear tires lock up just a little before the fronts. the rear discs made a slight improvement in braking over the stock drums, but then when I did the master cylinder t eh braking was improved BIG TIME.

 

[Longjohn119]

I know which coupler I could have used but decided to run new from the master back to the flex hose on the rear axle (I see flaky rust on a brake line I'm changing it all out) .... and the connector on the master was a metric bubble flare (AKA European flare) but at the rear axle was standard double flare ... since I live a block from an Advanced Auto, already had the truck on jackstand and didn't want to hassle running to rent a double flare tool I attempted to do it with two pieces of ready made line, a coupler (which looked to be the same to just bypass the RABS module) and figured "Everyone has an adapter for this master cylinder, there are only a few million of them out there" .... well no aftermarket stores stocked one and the Ford dealers were closed so I rented a double flare tool (which you can use to make reverse/european/bubble flares too) and used the old connector at the master, a new one for the rear and one piece line which is really what I prefered ... it just turned into a time consuming PITA that ruined my fishing plans for Friday night ....

Sort of a belated welcome to Ford, I've been working on them since my 1st car, a '67 'Stang I bought 30 years ago .... I've come to have a love/hate relationship with their little idiosyncracies (Like disc brakes and the yearly recall for "slips out of Park") but still, you don't mix two entirely different standards on the same brake line unless some idiot decided they could save 50 cents a truck by doing so ...

Interchangability of parts over a wide range of models and years is what made Ford attractive and Top Dog in many ways, I can't remember owning a Ford that didn't use a FL1A/PH8A oil filter and that spans a range of engines from the 'Too Slow' 2.0 in my '85 Ranger to the 360+ HP 429 in the '71 T-bird I had ... Ford master cylinders used to all use the same fittings

Brakes sure feel good now and I won't miss the RABS which never worked right IMHO even when brand new .... I'm with you, I like my trucks to feel like a truck, next up is new shocks to get rid of that 'Soccer Mom' ride ... after it cools off again

 

[410Fortune]

"time consuming PITA that ruined my fishing plans for Friday night ...."

thats what I was talking about hahaha Car Quest stocks the metric fittings.
my 88 BII lines are different from the Explorer even so it was just as tricky...

I can flare pipes, but not when it comes to brake line, I found standard lengths of hard lines worked perfect just had to bend them up.

these trucks are odd ball because the drivetrain is german, who knows who built the ABS system, french for all we know! hahaha

Hey any monkey can assemble a Chevy, you can buy a new intake at Wal Mart for those, it takes some thought to put together a Ford

 

[Creager]

I could brake the truck better on my own. that sucker would kick on and the truck would get sideways on just damp roads....

i know exactly what you are talking about, my sport does this. you dont even have to be moving that fast or real braking hard.

so i all i need to do is run new brake line from the master to the rear to bypass the RABS? and remove all the RABS stuff?

 

[410Fortune]

no you need to run a new line frmo the master only if you convert to rear disc brakes.

You can use a single adapter to replace the space the RABS module takes up in the rear brake line, slight bending required.

then just remove the wiring and control box = golden.
My RABS light that is in the dash is now my OD on/off light, with my conversion I now have a pushbutton OD....

rear discs are the next step IMO, such an upgrade!
especially on the trail with 35" tires, like when you have to stop on the face of a rock downhill, or towing....