'97 Taurus 3.0 OHV: Brake Piston Fell Out

Maintenance/Repairs
1

Brake pedal was going to the floor. Plenty of fluid in Master Cylinder.

Pulled both front wheels off to find no sign of any leaks anywhere. High and dry all around.

Metal lines look like new the length of the car. No rust, no sign of any leakage. Clean and clear all around (this is a southern car).

Didn’t pull the rear tires off, but just by rubber-necking with a flashlight, all dry back there, too.

So I removed the bottom bolt on both front calipers and swung them up out of the way.

Then I started pumping the brakes to see if the pistons moved.

Two rounds of about 6-7 pumps of the pedal, and nothing. No movement.

Third round, shocked to see both pistons came nearly all the way out!!! In fact, when I touched them, they wobbled. They were hanging by a thread.

So I tried using a C-Clamp and old brake pad combo to try to push the driver’s side piston back in.

But the (fairly large) C-Clamp wouldn’t open quite enough, and unequal pressure was applied to the face of the piston.

Next thing I knew, the whole thing exploded with the piston falling out, and all the fluid gushing out to the ground.

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Should I just pull the passenger side piston off now, too? And let that fluid also gush out? (all this fluid is pretty much original from the factory, so it’s old fluid anyway.

Do I just place the piston back into the bore, refill, and bleed? The piston just sits in there loose like that with only the rubber seal holding it in??? Or are these calipers history?

What about the pads and discs? Some of the fluid got on the bottom half of the disc and one of the pads. Just wash it off with brake cleaner and let dry prior to reinstall?

'97 Taurus GL Wagon 3.0L OHV
205k miles

2

Have you ever rebuilt calipers? That’s what you need to do here, then put them on and bleed the brakes. But it still isn’t clear what the problem was, you may have to use a power bleeder or vacuum bleeder, then figure out what else is wrong.

3

Go to the parts store and buy 2 rebuilt calipers and brake fluid for you car. Install them, bleed the system, and then start over. Never push the brake pedal with the drums or calipers off.

Before you blew up your front brakes you had the symptoms of a bad master cylinder.

4

I would get a caliper rebuild kit and go ahead and put in the new seals, or just buy new or reman calipers. You can clean the pads and rotors, but if they are more than half worn, I’d go ahead and replace them. That will save jacking the car up and doing that job later anyway. If you do replace the pads and rotors, try Wagner Thermoquiet Ceramic OEM pads, you won’t be disappointed.

Now pull off the rear wheels and check for the brake adjustment. The rear brakes get so little wear that it is not uncommon for the star wheel to get stuck so the self-adjusters don’t work anymore. Eventually you are using all your pedal travel to get the shoes out to the drums.

Also, you can get a special tool to assemble the calipers or use a pair of 16" Channel Locks. I prefer the Channel Locks. I have seen both the special tool and a C-clamp punch a hole in the bottom of the piston if you aren’t careful, never happens with the Channel Locks, and you can use those big Channel Locks for plumbing repairs as well.

Since your car is 16 years old, why not replace the rubber brake hoses while you are at it.

Welcome back, it has been awhile.

5

Believe it or not, the brakes were fine when I started the inital project: Engine front cover gasket and oil pan gasket. But that (side) project went on and on for weeks and weeks, and after I finished and started the car it shot coolant all over the place. Disgusted, and with plenty of other things to do (daughter entering college in Boston, travel for training, etc.), I let it sit there while I decided what to do next. When I got back to it, it turned out the water pump, which was fine when I started this job, was leaking out the weep hole, and the bypass “H” hose that runs parallel to the firewall had suddenly blown a pin-hole leak at the driver’s side “T”. So I replaced the water pump and hose and now no leaks (and I thought I was done), but then the brake pedal suddenly went to the floor!! First time I’ve ever experienced this on any car I’ve ever owned. So, with no obvious leaks - including at the Master Cylinder, I was at my wits end as to what the problem was, so that’s when I (stupidly) pulled off the calipers to see if I could get the piston to move. The idea was to just move it a little bit, but I didn’t have a helper, and I over did it.

I should’ve just tried bleeding the brakes first, but that didn’t make any sense because I never opened the lines and the fluid level looked OK.

So it’s either rebuilt calipers (and no, I’ve never done that), or just buy them rebuilt. Then I’ll probably find out the master cylinder is history? And this just happened while the car was sitting dormant? You know - a lot of the time, the car was sitting on one jack stand on the passenger side. Could that have tipped the fluid in the Master Cylinder enough to allow air to get into the lines if the fluid level was right on the border line?

While you guys were responding, I was trying to push the piston back into the bore with a C-clamp. Got it in about a 1/3 of the way, but no more. Not enough leverage to finish it off - even with a pipe sleeved over the 90-degree dowel handle on the end. Maybe a ball joint press would do it?

And yeah, Keith … can’t remember when I last posted on this board. Hope everyone is well and that Saturn is still running somewhere…LOL !

6

Really, that is how you punch out the bottom of the piston. Here is your excuse to get a 16" Channel Lock pliers. An alternative is to use an old brake pad over the top of the piston so you are only pushing down on the skirts. A solid flat piece of steel can work also. The piston might be cocked.

If you have ABS, you must open the bleeder valve to get the piston to go in, otherwise you can damage the ABS system.

Saturn 265k miles, just took it on a 15 day, 6897 mile trip to several national parks out west.

7

By the time you buy two new pistons and seals and sand the bores and clean with brake cleaner you will deserve two new calipers. So save time and effort and buy the new calipers.

8

keith:

I tried the brake pad method because that’s how I always push the piston back in when I’m changing the pads. The result was a warped brake pad backing plate and cracked pad!

Anyway, today after work I cleaned the calipers with brake cleaner and the passenger piston dropped in with just a little coaxing. But the passenger side piston (with it’s 1.5" long scar/scrape from using the C-clamp) just would not go in. So I tried dropping the unblemished piston into this bore and it did go in … but again - the scarred piston would not go into the passenger-side caliper.

So at the very least, I need a new piston, plus the two seal kits ($15 + $5 + $5 = $25).

But as you’ve all suggested already, buying the remans is probably the better way to go. About $60 for both from Advance after 20% discount and core refund. And they come with new bolts and bolt boots, too. Putting the original calipers on was more about ‘keeping the car as original as possible’, but I guess there’s really no sense in agonizing over that.

Keith - 265k miles !!! You’ve topped even my '89 Dodge Colt with that thing now! And you drove it on a long-distance trip 7,000 miles??? Now *that’s confidence !!! Only a mechanic would trust a car with that kind of mileage on a trip of that length. If I ever get the Colt running again, I doubt it’ll go out of town very much - unless I move back to New England; then it’ll have to drive about 900 miles one-way … like it did on our maiden voyage back in '95. It had 150,000 miles on it at the time, no problems whatsoever. About 350 miles into the drive (New Jersey), the alternator went out! Wife was 7 months pregnant. Called AAA, but because it was MLK holiday weekend, the guy couldn’t tow me anywhere. Asked for a tow to a hotel … he wouldn’t do it. Took off. So I drove it about 15 more miles on a dying battery (in the dark) to a Ramada. Next morning called “Aid Auto” to buy the alternator and tools to install. Guy behind desk saw my pregnant wife busting at the seams and offered to install at garage about 5 miles away. Took the car there, “Henri” put it in in about 30 minutes and we were on our way (500+ miles to go). Still got the picture of “Henri”. Columbian guy, as was the guy at the auto parts store.

9

I’ve used an appropriately shaped piece of 3/8 inch plywood – maybe thinner than that actually – over a disc brake caliper piston and pushed it back with a C-clamp or big channel-lock pliers before. Have to be careful it is going straight and not cocked though. It will go without a huge amount of force if it is properly aligned. If I had accidentally pushed the brake pedal with the caliper off, I’d remove the piston entirely, let all the fluid drip out, then install piston first, before trying to push it back. No sense fighting all that extra fluid. Good on you @ColtHero for not giving up, and giving it the old college try.

10

Cracked the pad eh, thats why I said “old pad”. Been there, done that. BTW, for the trip, we packed our stuff in backpacks instead of suitcases, just in case my “confidence” was misplaced. Had a great time visiting all those parks that are now closed, but I had an unexpected highlight at the Crazy Horse monument. Split window, fuel injected, 4 speed. Windows down and doors unlocked and no key needed that year.

11

GeorgeSanJose:

I’ll have to take Keith’s advice and spring for the 16" Channel Lock pliers. I could use that tool in my set.

As for not giving up, sometimes I just turn my projects into side-show experiments for a while, much to the chagrin of my wife. She’d love to see me ‘give up’! She thinks the Taurus (now the 3rd car) is a junkyard car, and she refuses to drive it. Me, I’d like to see it go 300,000 miles. Never had a car go that far. Colt stopped at 255k.

keith:

It was an old pad. I’m always ahead a set of pads on my cars so that I can trade in an old set (not currently installed on the car) for the next set of free warranty pads at Autozone. I may have to get the sledge hammer out now to straighten this one pad out so I can trade it in next time. I think I may have also kept the spent pads from the '98 donor Taurus just to make sure I had overstock there, too.

That '63 brought back memories for you?

12

No, dreams. But yeah, I do remember when it was new, but I was 14 at the time. The Beach Boys had a song about it. A friend of mine bought a 67 Sting Ray with a 427 when I was in High School. He came into a big inheritance and it ultimately ruined his life, wasn’t mature enough to handle it.

Pissed him off when we got into a drag race with my 57 Olds Super 88 Coupe and I blew his doors off. The Corvettes were a road car. They had an independent rear suspension. Back then with the skinny tires of the day, the Corvette would squat down off the line and that made the rear tires camber in real bad so they couldn’t get any traction, just like in the song. Once they got above around 40 mph, then they started coming on strong, but by that time I was up to around 70. On a track, he would have caught me but we were on the street and it wasn’t long enough for him.

13

Ordered the new Wagner piston, two flexible front-end brake lines by Raybestos (thanks, Keith), and two Carlson seal kits from Rock Auto for $38 delivered. All three were closeouts. Hope these parts weren’t closeouts because they were lousy products!

Would’ve preferred to just get it locally at Advance, but the piston had to be ordered, and one of the brake lines was out of stock, so this time RockAuto made sense. Most of the time when I check RockAuto, the price is initially lower, but then with the shipping costs it ends up right there with Advance’s price (where I can get the parts immediately).

I almost bought the rebuilt calipers, but ultimately decided this probably wasn’t necessary. Question came to mind, though: How are cast-iron calipers “re-built” (or are they just melted down)? If the bores are shaved, doesn’t that mean larger pistons need to be installed?

Keith:

Nice muscle car story. You know, you’ve got a few years on me. When I was 14, friends were souping up '69 Novas and Chevelles. Best friend’s older brother had a friend that used to drop by in his completely muscled out Cherry Red '57 Chevy wagon. Boy did that car really catch the eye - it was so different looking. They’d drag race at the Industrial Park which had two LONG strips custom-made for such events. Police would sometimes intervene, and I think nowadays they have installed several speed bumps to completely stop that activity.

14

I’m guessing you could have bought a rebuilt caliper for about $35. Why bother with trying to rebuild yours? Do you have the appropriate size hone to deglaze the cylinder wall? Or are you just going to use some crocus cloth wrapped around your finger? Will you be able to get the correct cross-hatch on the wall? Did they also sell you a bottle of brake assembly lube to use to assemble the piston into the caliper without tearing or rolling the seal? Do you have an appropriate tool to install the dust boot properly? A rebuilt caliper will have all of these things done already. I assume you also bought new pad hardware and caliper bolts and pin kits, which would also come with rebuilt calipers. Plus, they’ll have a warranty.

15

asemaster, you fell into the same trap that I fell into on another thread about rebuilding calipers. You don’t need to hone or deglaze the bore, the seal sits in a groove in the bore and the piston rides on the seal. I have rebuilt quite a few calipers using brake fluid as the assembly lube and never needed any special tool for the dust boot, though they are a bear to get in right.

16

asemaster:

I appreciate your professional perspective - and I certainly respect it, but it turned out nobody ever gave a compelling reason why I couldn’t re-use my calipers. The argument was mostly: ‘why waste your time when remans are so cheap?’. Well, time is not of the essence here. The experience is more important to me - even if it’s a bad one. My thinking was this: unless the cast iron caliper has been distorted by extreme heat (improbable, since the piston still rides in the bore well enough), and even if the wall of the bore is scratched or somehow rusted, the seal with the piston occurs at the embedded O-ring which sits in a groove that is “protected” by the seal. My seals came out pristine (as did the dust covers), so that interface was still good. To me, this meant that all I needed to do was cleanup the bores a bit and replace the rubber. I did almost purchase a honing tool at Harbor Fake to do the bore cleanup, but ultimately decided to go with ultra-fine sandpaper instead because I wasn’t sure that the hone was the right size, or that I wouldn’t OVER-hone the bore using a tool I wasn’t familiar with.

Very surprised, however, to hear that the dust boot is going to be difficult to attach. Sure came off easy enough. What’s the problem - you have to kind of open the accordian a bit to attach the lip and the thing is going to want to repeatedly snap closed (or retract) on me?

Lastly, just to answer your questions:

No - no new caliper bolts or bolt dust boots. Originals look OK. Pads have been replaced several times over the years and never any mention of need to replace these bolts, so why replace them now?

No - no new pads. Pads I have are fairly new. And from what I could gather, pads only come with reman calipers if you buy them “loaded”, which is more than $35.

Not trying to be a wise-guy here … I just think you are trying to impress upon me the “professional” solution - which I appreciate, however - my question is - is all that stuff absolutely necessary, or just ‘good practice’ techniques.

17

Hero, how have you been?? We have missed you here! If you couldn’t get it back in with a C-clamp, it’s time for a pair of rebuilt ones…With the bleeder open, you should have been able to push it back in with your fingers…Don’t bet your life on a cobbed up brake system…If the pedal went to the floor full of fluid, no leaks in the system, then the master cylinder is shot, replace it too…

18

@ColtHero, the answer is ‘good practice’. For a couple of dollars more, you could have remanufactured calipers ready to install, instead of wasting an hour or so rebuilding yours and hoping you get it right. Get something wrong, and you’d be back at square one.

19

@ColtHero

Hey, if time is not an issue, then go for it. I’m certainly not being judgmental here, but for a vast majority of people, buying a completely rebuilt caliper for $35-$40 is worth the time, effort, and mess of rebuilding one yourself. Ditto for the slide bolts (pins). Completely disassembling them, cleaning and lubricating with fresh appropriate grease is standard procedure for just a pad replacement. Replacing them with new is part of a caliper rebuild.

The dust boots can be difficult to completely seat properly and can tear easily in the process. But take your time and be careful and you should be fine.

You could reuse your old calipers, but how long would they last. Both personally and professionally I’m a believer in not doing the same thing over again. Assuming the brakes my car came with originally lasted 50,000 miles, I’m going to do what I can to ensure that the replacements last that long as well. I’m not fixing my brakes today and then have to do it again a year from now. Repairing or replacing anything that shows moderate signs of wear or is marginal in function is part of that idea.

All these things are part of “Best Practices”, but also remember, those of us who do this professionally have to warranty our work for at least 12 months/12,000 miles. And while rebuilding calipers can be educational and fun, for those of us doing it for money the goal is the highest quality repair in the least amount of time. I’m not going to spend $40 worth of time to rebuild a part when I can buy one for less that is probably higher quality.

It’s like golf. Playing golf is reasonably fun exercise, I like to do it, and the more I do it the better I get. So it’s something I try to do whenever I can. But if someone said “You have 3 and a half hours to finish this round and you have to score less than 100 or you can’t do it anymore” that would take all the fun out of it. I guess that’s why pro golfers call it work.

Anyway, take your time and be careful and you should be fine. But then we still need to find the cause of your original low pedal, right?

20

Taking the dust boot off is a whole lot easier than putting one back on. Kinda like letting the cat out of the bag, its a whole lot harder to get it back in.

You can try to put the base of the dust seal in the top groove of the caliper bore and then slip the top around the base of the piston. That works on some models, but I have had little success doing it that way. I have done it that way but most of the time, the base slips out of the groove while you are trying to stretch the top around the base of the piston.

Usually I end up getting the top around the base of the piston, then extending the base out and try to get it into the groove. A new dust boot does not like to extend so it gets really frustrating. It generally takes many tries before everything finally comes together. I will say that some are easier than others.

But I do agree with asemaster that for the pros, you would just loose too much money rebuilding calipers, it just takes up too much time compared to the cost of a reman.