Never ending brake trouble

[JohnW63]

I believe my '95 ATX has had a brake problem since day one. The REAR brakes wear out so much faster than the fronts do. I bought the car , from my in-laws, at about 36K miles, and I don't think they had the brakes serviced during that period. Some time after I bought it, I heard the tell tale sound of metal on metal, ( Why doesn't this car have a mechanism to alert you to a worn brakes condition !? ). I took it to the dealer since I had an extended warranty. They found that the right rear rotor was trashed and the left rear was starting to scratch. The fronts were fine. When I asked to see the front pads, they had convienently thrown them away, so I don't know how far they had worn. Less than a year later, I thought I heard it again. I took the car to a third pary garage and they said the right rear caliper was hanging up. I took it back to the dealer and they supposedly cleaned and lubed the caliper and it was fine. SOme time last year, my father in-law replaced all the pads again, sine they sounded like they were squeeling. The rears would squeak a LOT after that job, but my father-in-law couldn't hear it. ( He's not as young as he used to be. ) I took the rotors off, had them all turned to be sure they weren't off, replaced all the pads with AutoZone lifetime stuff, lubed all the caliper pins , adjusted the parking brake, and still couldn't keep the rear pads from squeaking, especailly when I would turn corners. The sqeaks slowly went away, but...I was checking the air in my tires, yesterday, and saw the rear rotors were scored quite noticably.

Is there a proportioning valve that could be bad ?
Is there a way to check the pressure at each wheel and see if it was off ?

I'm REALLY getting tired of this !!!

 

[jasonty]

Sounds like a bad problem. Yes, there is a proportioning valve for the ABS system that regulates flow to each wheel, but they don't frequently go out. I don't know where it is located on the SHO's, but on Chevy's, it's usually on the framerail somewhere, or near the master cylinder. Pull your calipers off and look at the piston seals. If the seals look misfigured in ANY way, (cut, cracked, dry-rotted, one part sitting higher then the other) either buy new seals or go and buy new calipers since the seals are not a fun job to do unless you have the right tools. If you decide to replace the seals yourself, clean the bore and piston of the caliper as well. You can use a VERY VERY fine grit of sandpaper to do this. I'd go with 4000. Also, check the adjustment of your parking brake cable, and make sure it isn't too tight. Also check to make sure the brake lines aren't bent or restricted in any way. Not just the lines that go to the calipers, but the ones that come out of the master cylinder as well. Good luck, hope this helps.

<small>[ March 09, 2003, 04:56 PM: Message edited by: jasonty ]</small>

 

[Bizzy]

I've had the same problems in the past. Here's a few things to check and the location of the "prop" valve.

First, the prop valve is located inside the rear driver's side wheel well area behind the strut. It's a boxy looking thing with 4 small tubes sticking out of it. I replaced mine last year, got it from Ford Parts Network for I think $80 something shipped.

Things to check.

*Calipers, if they get overheated from rubbing, they're toast.

*Slider pins and boots. The slider pins don't do a darn bit of good if they're not lubed (as you know) but also, the **** doesn't do a darn bit of good if the boots aren't seated properly. It will allow dirt and moisture in and the **** to go out.

*Brake hoses, they may look good on the outside, but the inside of the rubber hose tends to collapse with age. Do your brakes bleed properly?

*A very important item to remember are the brackets. You can replace the slider pins, rotors and calipers every month and if the bracket holes where the slider pins go into are crudded up it's not going to do you a bit of good and you'll be in the same position a month from now as you are today. Check those brackets, if they're crudded up inside, I'd suggest buying new brackets because once they are contaminated inside it'll just come back when more moisture gets in there.

*Rotors, when you buy them, make sure you ask for the OEM rotors. They do cost more, but the hat on them is not as tall as an aftermarket rotor. What's that got to do with the caliper and your problem at hand? Not much, but more of an FYI item. And the extra height will mess up your offset if you ever decide to upgrade to a larger sized rim/tire.

After all my headaches in the past, I ended up replacing the rotors, calipers, prop valve, brake hoses, slider pins and the brackets. Since then it's been smooth sailing.

<small>[ March 09, 2003, 06:02 PM: Message edited by: Bizzy ]</small>

 

[rangerj]

JohnW63,

To add to the above post, also consider the following. The master brake cylinder has a very small fluid return hole that allows the fluid to return to the resevoir after the pedal is released. If this hole gets blocked then the pressure on the lines is not released.

In your case both rear brakes are prematurely wearing out. This tends to indicate an emergency brake cable issue. The duel master cylinder is split right rear/left front, and left rear/right front.

A master cylinder problem would present itself as a rear/front problem. The same is true of a proportioning valve problem, as the lines get their pressure from the master cylinder.

Both of the rear lines could have been hit by road junk and are crimpted. The lines have some sort of internal blockage, or the emergency brake cables are not adjusted right, or are not fully being released (usually due to corrosion).

Hope these other possibilities help, rangerj

 

[JohnW63]

An Update:

I pulled all the wheels off and inspected things.

No crimps in the brake lines anywhere that I can see.
The parking brake ajustment was still slightly loose when in the released position. ( I think an 1/8th of an inch is called for. )
I need to check the brake bias adjustment. That's the block by the back wheels with the 2 lines coming in abd going out that decreases the brake preasure when the nose dives and the rear of the car lifts.
I replaced the rear pads. I had had them on for almost exactly 1 year and well under 10K miles. I'll have to have the rotors turned at a shop, but they were not open on Sunday.

Here's the part that sounds suspect. I could not get the caliper piston the spin back in by hand. On the driver side, I found that if I really opened the bleed valve and used an air ratchet, it finally went in OK, but it needed presure. On the passenger side, when I tried the same method, not much fluid came out and the piston didn't go in. I had to take the fluid line off and hold the caliper on the ground and REALLY push with the ratchet to get it to go down. When I did the brakes last year, I recall that when I bled the lines, the flow of fluid was much less on the back brakes than the front. I also noticed that the slider pins were not shiney anymore. More of a dull grey. The boot on them seemed OK.

I may go ahead and order new calipers and pins for the rear. I don't like fighting with the darn things to get the piston back in.

Who has the best price on calipers ?

JohnW

 

[Mr Anonymous]

JohnW63:
Who has the best price on calipers ?

AutoZone sells a pair of loaded rear calipers (loaded means it includes pads, caliper brackets, pins, boots, etc.) for just over $100 + core. It's a special order item that takes a couple of days to get, but if you're doing the labor yourself it's still much cheaper than going to Midas, etc. If you add new rotors (about $45/pair at AZ), you probably shouldn't have to attend to the rear brakes for another 80K+ miles.

 

[jasonty]

Save yourself the hassle and remove the piston and clean it with some crocus cloth or fine grit sandpaper. It's probably just corroded.

 

[N.Pinto]

Sounds to me like your hoses are bad. I went through this same situation last year. My rear brakes, mostly the pasenger side, were dragging. I was going through pads in less than 6 months (about 10k miles for me) Returning the piston was near imposible, had to take the caliper of the car.

Before I replaced the hoses I rebuilt the caliper, becuase the previous owner/owners mechanic tore up all the seals and the piston was rusted. Replace that with a new caliper when that didn't work thinking that the caliper was damaged (from use of wrong tools by previous mechanic) or piston to badly pitted, spent days adjusting the proportioning valve, and cleaning and polishing the slider pins and there brakets. Nothing worked.

I noticed after replacing the hoses that when bleeding the brakes the fluid has a rather large, powerful arch, hit the back of my wheel well a few times. Old hoses barly made it past the back of the caliper. Also the hoses should have a steady drip of fluid, old did not. Also was able to return the piston rather easily while on the car and bleeder closed.

Hope this helps, (wish I knew about SHOforum then!!!)

 

[JohnW63]

More info:

After doing all the above mentioned stuff, I needed to bleeed the brakes. I was able to get an OK stream of fluid from the left front, and almost as much from the right front. The back ones just dribbled. I had the wife pumping up the pedal and pressing hard, when I opened the bleed valve at least 5 times, and nothing but a dribble came out.

I am wondering about the brake bias block, since that is inline with only the rear brakes. I gave it a look over, but I couldn't see how it would work. There looks to be a small rod ( Not the long one with the spring and adjuster nuts ) that might be pushed in or pulled out as things move, but it was not attached to anything on one end. It just passed through the opening on the part that moved. Can anyone e-mail me a picture ? I have the big Helms manual, but the diagram does not show that side.

Oh, and another thing. When I put the new pads on the car, I noticed that what ever pad I put in the back side of the rotor, sat up about 4mm taller than the rotor and the outside pad was flush. Is that normal ?

NPinto,

What section of hose are we talking ?

JohnW

<small>[ March 10, 2003, 07:43 PM: Message edited by: JohnW63 ]</small>

 

[JohnW63]

SHOooo,

The dude at my local AutoZone came up with nothing. I checked at thew AZ web site and the only think I found was a caliper that had the note of "semi loaded". Could you point me to the right part number ? I know AZ sometimes will list a part for one year and NOT another, even if they are the same part.

NPinto,

Did you mean the rubber brake line section that goes from the hard tube to the caliper ?

JohnW

 

[Bizzy]

Not Autozone, but just as reliable thumbs_u www.rockauto.com

Rear left, loaded - Cardone# 164537 - 57.28 + 50.00 core

Rear right, loaded - Cardone# 164536 - 57.28 + 50.00 core

 

[Mr Anonymous]

JohnW63:
SHOooo,

The dude at my local AutoZone came up with nothing. I checked at thew AZ web site and the only think I found was a caliper that had the note of "semi loaded". Could you point me to the right part number ? I know AZ sometimes will list a part for one year and NOT another, even if they are the same part.

WELL.... The part number is 13-606667, made by ARI. I just checked their website and they now show it as unavaliable! eek! I last checked the price on them less than a week ago for someone and they were still listed as available by special order for $106.99 + $90.00 core...

As Bizzy mentioned, RockAuto.com has the A1 Cardone loaded rears (P/N's 16-4537 & 16-4536) and they comee with a lifetime warranty. At the very least you could also take the two Cardone P/N's and call around locally for prices.

<small>[ March 10, 2003, 11:10 PM: Message edited by: SHOooo ]</small>

 

[luigisho]

John, when you bleed the rear brakes you need to apply load to the wheels to get the fluid to flow. Jack the back up, put stands under there and use a jack under the wheel to open the line up or put alot of weight in the back.

 

[N.Pinto]

The hoses I'm refering to are the rubber hoses that contect to the caliper from the hard brake lines. The inside of these hoses tend to deteriorate and collapse with age. This will not let the brake fluid return and keeps the pressure on the pads. (Which is also what makes returning the piston near imposible)

One suggestion if you do change these is to be carfull removing the end that attaches to the hard lines. The nut is rather soft and will round off easily. Let some penitating oil set in for a few minutes first, use a good fitting Flare nut wrench, don't strong arm it off.

<small>[ March 11, 2003, 09:51 AM: Message edited by: NPinto ]</small>

 

[JohnW63]

luigisho,

I didn't know how much the bias valve would reduce the fluid flow. Maybe I'll put a stack of 12" square paver blocks under the rear tires.

I found out today that the rotors are too thin to turn again. I'll need rotors too. Who has GOOD ones, and which ones should I avoid ?

JohnW63

 

[Dave Kegel]

Make sure you compress the driver's rear suspension before trying to bleed the back. If you leave the suspension drooping the proportioning valve blocks fluid flow.

Once you bleed the brakes, drive the car around and then jack up the rear end and spin the wheels. If they spin freely, you're OK. Now try it again after you use the emergency brake. If they don't spin freely, then you've got a sticking e-brake cable.

As for the rear piston not going in easily, that's not necessarily unusual. You need to use a special tool, or vise grips, and even then they're sometimes a PITA to screw back in, especially if you don't loosen the bleeder screw first.

Dave Kegel

<small>[ March 11, 2003, 01:34 PM: Message edited by: Dave Kegel ]</small>

 

[JohnW63]

Dave,

I have the special tool from NAPA. It's much better than the lame cube version. I had the bleeder valve completely OFF, when I struggled with the RR caliper. It seems to me that it should not be so hard.

Anyone have a suggestion on rotors ? It looks like the ones around town are just a solid rotor, where as the stock ones have air channels through the center. I would think that the Ford ones stay cooler.

JohnW63

 

[Bluto]

Don't bother jacking up the car, and blocking the wheel, and supporting this and that....just bleed the rear with the car on the ground. I am big boned thumbs_u and I can lay on my back and reach the bleeder.

 

[Dave Kegel]

Anyone have a suggestion on rotors ? It looks like the ones around town are just a solid rotor, where as the stock ones have air channels through the center. I would think that the Ford ones stay cooler.

Are you referring to a vented rotor, like the front ones? The '93 and up SHO has a solid rear rotor. '89 - '92 had vented rear rotors. You unfortunatley can't put a vented rotor on the newer cars. Well, not without a lot of work.

Dave Kegel

 

[JohnW63]

Dave,

You're right. Vented in the front. Plain in the back.

I got some $22 Raybestos ones from Kragen.

On the hoses. Do I NEED real Ford ones , or do the third party guys make good ones ?

Since both rears have been a problem, ( Although, at first, the right rear was worst ), what is the chace that the hoses would both go bad, by 40K miles ?

What is the proper routing for the parking brake cables ? I was wondering if they could be routed wrong, and when the suspension moves, it tightens the brake.

JohnW