Author Topic: Brake caliper piston  (Read 7345 times)

Offline Brass_Machine

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Brake caliper piston
« on: May 26, 2014, 09:00:19 PM »
So my truck has had some disastrous events happen to it lately. The front brakes on the passenger side started grinding, so I went out and bought a set of pads (cheap) to get me through tip I had the cash to swap the rotors as well (they were kind of ground up). Only did the one side because the drives side "seemed" ok.

Took the truck to my in-laws house and it the drivers side started grinding when I got there. No tools. The other pads were back in the garage at home. Figured since it just start grinding, I would be OK getting it home.

Well... I was wrong. Between the pads being nothing more than the backing plates and the carrier guide pins sticking, the inner pad (what was left of it) basically fell out. When I went to stop, the piston ground against the rotor. Had to get towed home. So I ended temporarily tossing the new pads on (again until I got the cash for the rotors) and drove it back and forth to the train station so I could get to work.

Ordered all the parts I needed to do an entire front end rebuild. Been working on it for the past week. Parts for my truck are like trying to find hens teeth, so I had to go to ebay to get a few things. One of them being a replacement piston for the one that had contact with the rotor.

So being the knuckle head that I am, I ordered the wrong piston. I got the one for the rear brake caliper (at least the rebuild kit was correct). I don't have the time to send it back and get the right one. So my question is this: The damage to the piston is very light. I am thinking of just cleaning it up and squaring it in the lathe. We are talking minimal material to be removed (maybe .0625"). Am I crazy to do this? I need to get this POS back o the road ASAP.

Eric
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Offline vtsteam

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Re: Brake caliper piston
« Reply #1 on: May 26, 2014, 09:57:14 PM »
Sorry that happened to you Eric!

Well, if you do face the piston down, seems like it ought to look to the cylinder like you have ,0625 wear on the pad, and ought to self adjust for that. But I would be sure to order the correct piston and replace it asap. Because it may get too far out of the cylinder when you get real wear on the pads, since you ahem, drive 'til they grind!  :poke:

Did you hear squeaking of the wear indicators before the actual backing plate grinding started?
I love it when a Plan B comes together!
Steve
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Offline Brass_Machine

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Re: Brake caliper piston
« Reply #2 on: May 27, 2014, 01:23:52 AM »
Sorry that happened to you Eric!

Well, if you do face the piston down, seems like it ought to look to the cylinder like you have ,0625 wear on the pad, and ought to self adjust for that. But I would be sure to order the correct piston and replace it asap. Because it may get too far out of the cylinder when you get real wear on the pads, since you ahem, drive 'til they grind!  :poke:

Did you hear squeaking of the wear indicators before the actual backing plate grinding started?

Nope. No squeaking. Whoever did the job before me cut them off!  :doh:
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Offline vtsteam

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Re: Brake caliper piston
« Reply #3 on: May 27, 2014, 09:16:52 AM »
Oh, that's nasty!

Well, hope things get better for you -- I know the feeling when your wheels start making demands rather than suggestions!

I had a coil go out on my pickup truck a couple months ago. Started having misfires when it rained. Replaced plugs and wires first, but it got worse, finally I had to face the fact it was of course the most expensive part -- ignition electronics were potted into it. Well, anyway, got new wires and plugs in, too, so no worries re. ignition from now on.

My wife's Honda Fit has been giving us fits. The key will hardly turn in the ignition any more, The dealership wants $400 to replace the ignition lock AND she will then need two keys, since it will be different than the door locks. If she wants them re-keyed, it's $1000. But not only that, the hatchback door lock is now also non functional. Honda builds respected engines, but hasn't yet conquered door latch and lock design. This is a 2008 vehicle which is nearly inoperable by now.

Non-dealer and non OEM  ignition lock replacement won't work because Honda won't release the digital codes for the anti theft programming. It's "proprietary".

Anti-theft means that street thieves have simply been replaced by the dealership. We will soon need another thousand bucks just to get into or drive our car.
I love it when a Plan B comes together!
Steve
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Offline Brass_Machine

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Re: Brake caliper piston
« Reply #4 on: May 27, 2014, 10:01:02 AM »
Hey Steve...

Dunno if this will help, but I fixed a sticking ignition key on a Porsche lubricating it with graphite powder. I was able to buy a small tube of it and was able to squirt it in. A few turns with the key helped with dispersing it through the tumbler and was soon working better than new.

Eric
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Offline David Jupp

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Re: Brake caliper piston
« Reply #5 on: May 27, 2014, 10:06:48 AM »
I too have had car locks that responded well to lubrication - though I did have ignition lock on one car where lubrication only helped for a short while, in the end it jammed entirely (with key in).

Offline mattinker

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Re: Brake caliper piston
« Reply #6 on: May 27, 2014, 10:21:15 AM »
A good source of lubrication for locks is crushed graphite pencil leads.

Regards, Matthew.

Offline vtsteam

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Re: Brake caliper piston
« Reply #7 on: May 27, 2014, 06:24:38 PM »
Sorry, didn't mean to hijack your thread Eric!!!

Thanks to all for the suggestions, we tried the graphite trick a few months ago, and again two days ago when my wife was stuck at the grocery store, but it's getting worse. I've found a youtube of a fix which determines and removes the sticking tumbler from the ignition lock. Not looking forward to doing that. But $400 for a new one?  :(
I love it when a Plan B comes together!
Steve
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Offline Sid_Vicious

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Re: Brake caliper piston
« Reply #8 on: May 27, 2014, 08:27:43 PM »
VT Steam...The antitheft system is very often a sensor near the ignition that reckognise the code in the key and send a signal to a box on the carb or fuelrail opening for the fuel to flow. If you smashes that box and take away everything there you will end up with one wire you shall connect with positive. It's just an elektromagnetic shutoffvalve. There are some Youtube videos about it. Then you can use aftermarked keys and locks.
Nothing is impossible, it just take more time to figure out.

Offline vtsteam

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Re: Brake caliper piston
« Reply #9 on: May 27, 2014, 09:05:24 PM »
Hmmmmm, he said thoughtfully..........

I'm sure thieves don't know about that, too, right?      Right!  :bang:
I love it when a Plan B comes together!
Steve
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Offline PekkaNF

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Re: Brake caliper piston
« Reply #10 on: May 28, 2014, 01:29:00 AM »
VT Steam...The antitheft system is very often a sensor near the ignition that reckognise the code in the key and send a signal to a box on the carb or fuelrail opening for the fuel to flow. If you smashes that box and take away everything there you will end up with one wire you shall connect with positive. It's just an elektromagnetic shutoffvalve. There are some Youtube videos about it. Then you can use aftermarked keys and locks.

My wife had a cheapest Nissan ever and it's antiteft system was spawned by beleseebub himself. Ignition switch communicated to key and send the code to ignition module that did (or did not) accept it....and ofter that gave (or did not) signal out that enabled crankking and such. Once I had some slight trouble with in in -27C temperature and it was not much joy of trobleshooting it

I had a coil go out on my pickup truck a couple months ago. Started having misfires when it rained. Replaced plugs and wires first, but it got worse, finally I had to face the fact it was of course the most expensive part -- ignition electronics were potted into it.

I had some intermitent problems too, I had replaced plugs three months ago and the trouble disapeared until two weeks ago. Then I replaced HT wires (two had break on low voltage) and the coil, this is the system that has two coils pottet together and fires two cylinders simultaneously. Helpped a little while, but I found the original fault: there are some press-on steel plugs at the same plane than plugs, they seeped a little coolant, not much but eneough to keep the whole lot moist and because the whole lot (plugs/caps) is under seals it stays wet. When accelerated hard sparky finds alternative routes.

I had my share of brake problems, I'll try to replace parts, whenever thay are reasonable price, here they rust and if you'll touch anything you won't get it back. On one ford the pistons were pretty much rusted outside perimeter and did not go back when I were chancing the pads, I don't remember did I try to remove the rust or did I get the repair kit. I rmemebert that the pistons were surpricingly thin and had very weak top.  I have a look on brakes twice the year (when I change summer/winter tires).

Pekka

Offline vtsteam

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Re: Brake caliper piston
« Reply #11 on: May 28, 2014, 10:47:16 AM »
...On one ford the pistons were pretty much rusted outside perimeter and did not go back when I were chancing the pads, I don't remember did I try to remove the rust or did I get the repair kit. I rmemebert that the pistons were surpricingly thin and had very weak top.

Well that would argue against turning the piston in the lathe, to answer Eric's original question. I guess you'd have to look at it and judge for yourself, depending on the vehicle. But it seems like new pistons should go in there after any temporary repair to keep the truck briefly on the road.
I love it when a Plan B comes together!
Steve
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Offline Brass_Machine

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Re: Brake caliper piston
« Reply #12 on: May 28, 2014, 11:16:41 AM »
Well that would argue against turning the piston in the lathe, to answer Eric's original question. I guess you'd have to look at it and judge for yourself, depending on the vehicle. But it seems like new pistons should go in there after any temporary repair to keep the truck briefly on the road.

yeah, I wouldn't be turning it. Just facing it. Thankfully being a truck, it is a big thick piston. I am going to rebuild the caliper tonight (or tomorrow) and had planned on doing a thread on it...

Steve... Don't worry about hijacking the thread!
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Offline vtsteam

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Re: Brake caliper piston
« Reply #13 on: May 28, 2014, 11:51:34 AM »
Well Eric, you'll know better when you look at it and decide. It's always second guessing out here on the internet compared to what a person has in front of them on the workbench.

I once owned a 1941 Plymouth pickup truck that I bought at a junkyard and gradually restored. The brakes were shot (rear slave cylinders a mess) and I couldn't find a source for replacements, so I went down to the local parts place (this was about 1971 when they were still old fashioned, non-franchise, around here) and together we searched through boxes of slave cylinder to come up with a close match from something more "modern".

It had the same diameter and throw and fit on the plate with the same bolt locations, but the pushrods were obviously a little different than the stock Plymouth truck ones. So I just made up new pushrods to fit. Back then I didn't have a lathe (or know anything about them) and I just used a hacksaw and files on a piece of round bar. The brakes worked fine. A couple years later I came across a classified ad in Hemmings Motor News for proper replacement cylinders, sent for those, and replaced the converted ones. But they probably would have worked fine for a lifetime if I hadn't.
I love it when a Plan B comes together!
Steve
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Offline Brass_Machine

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Re: Brake caliper piston
« Reply #14 on: May 28, 2014, 12:16:20 PM »
I have been finding the franchised parts stores around here very unhelpful. Fortunately I found one a few towns over, while still franchised, has the old school feel to it. They even have stools in front of the counters and the parts guys know what they are talking about.

Science is fun.

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Offline vtsteam

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Re: Brake caliper piston
« Reply #15 on: May 28, 2014, 02:08:46 PM »
Yes, it's amazing, now if you don't quote exact make, model, year, engine size, body type, etc. it's hard to even buy spark plugs! That's because everything must be queried on the computer. Very difficult to cross reference parts for odd projects as a result.

A couple days ago I was looking for oil filters for the '54 Ford tractor, it had a OEM added spin-on filter adapter, and the parts list showed some oddball 1950's filter shared (after long internet research) by vintage Alfa Romeos as the proper one. These are practically unavailable except online and at a high price. The local franchises said they didn't have them.

But checking around the tractor forums a large percentage of Ford tractor owners for many models (including my 850) and many years use a Motorcraft FL-1A, a very common widely stocked filter. One person noted he used them on every Ford tractor he owned AND his farm vehicles as well. I did some comparison specs of the two types, and the newer FL-1A filter was superior in every respect, and exactly fit the adapter. At about half to 1/3 the price, So I went with it.

But I would have never been able to get that information at the local car parts franchise. Make, model, year, engine......
I love it when a Plan B comes together!
Steve
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Offline Scuba1

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Re: Brake caliper piston
« Reply #16 on: June 11, 2014, 08:48:47 PM »
I drive a  1996 Volvo 850 GLS I needed a serpentine belt, so looked online at the NAPA site ... went through the whole game online . Make . Model. year, engine size, how many valves, hair colour of the ex mother in law... the whole lot. Ended up with it being in stock at the local store, so I reserved it and went to pick it up.
Back at the dock, i did not want the hassle to un-thread the old one, so I cut it and pulled it out. Put the new one in and found that it was about 3 inches to long. So gathered up the rest of the old one and the new one, borrowed a car and went back to NAPA .... they had to do a bit of a search and apparently I am driving a Buick ... go figure.

ATB

Michael
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Offline PekkaNF

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Re: Brake caliper piston
« Reply #17 on: June 12, 2014, 02:54:18 AM »
Went for an anual check up for my Ford :lol:

Here cars need an anual inspection, they check OBD, emissions, suspension, brakes - all the works. Well my car did not pass! Not only that but they slapped me with "denial of road use" because front brakes were inbalanced. One day time to drive it to the garage and have it checcked!

It was 5PM, I called my broher to pick up brake pads and rotors, I was hoping it was not the caliber. Took coffee and went to change part. Rained whole time, nice to fix brakes when rain flows down on your neck, along the spine and down - you know where.

Found the fault, right side brake pad was rusted solid on caliber, pad next to was worn out. Changed pads and rotors, checkked and lubricated pins and moving parts. Now the new model brake cylinder is funny. Looks like piston is pressed steel cup and the other way around I'm used to - the rim is outside and top is inside! Brake pad had a huge clip that goes inside the brake piston cavity.

Took the car back for inspection. Now you better sit down when I'll tallyt the total:
104€ for initial inspection (20 mins, this must be a permission to print money)
136€ for front brake pads and two rotors (old rotors still had maybe one more year left, but shops were closing and I did not want to risk)
32€ for check up inspection (5 mins on brake dyno and paper work)

Luckily I did not need to drive it into a garage and pay 57-110€/h, minimum charge 1h to garage.

I almost said something that rhymes with a clackking bell. I could have used that money for my family or hobby.

Pekka

Offline awemawson

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Re: Brake caliper piston
« Reply #18 on: June 12, 2014, 03:07:17 AM »
But PekkaNF look on the bright side. They saved you from one day having to brake hard, swerving into a queue of women and children waiting for a bus because of your unbalanced brakes. And being imprisoned for manslaughter aggravated by 'failure to maintain in a roadworthy condition'

....it all could have been MUCH worse   :bugeye:
Andrew Mawson
East Sussex

Offline PekkaNF

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Re: Brake caliper piston
« Reply #19 on: June 12, 2014, 03:47:48 AM »
Very true and I actually asked about it. I did brake hard just few days before and did not notice anything. The inspection guy claimed that you won't notice that amount of  imbalance due to ABS on slipery surface and on dry surface it was not that much diifference as to cause problem - yet. Only if the another side brake was really really bad there would have been a real problem. I'm happy it got noticed and fixed - it's only the price tag!

I wonder how much different these new cars are and how much difference it is on roads...I haven't used dirt road on ages. Then again part of the problem is than now when tecnology is better we trust it to stay that way.

I'll chck the brake twice a year and did not notice anything out of ordinary two months ago. Now I know one thing to pay attention on my car.

Pekka


Offline Kjelle

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Re: Brake caliper piston
« Reply #20 on: June 12, 2014, 08:03:04 AM »
Pekka, do you know what "FORD" stands for in Swedish? Fodrar ordentliga reparationer dagligen... Just kiddin'! (Dream car is a group 4 Escort, in tarmac trim, like Waldegårds WRC tarmac car)

Kjelle

Offline vtsteam

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Re: Brake caliper piston
« Reply #21 on: June 12, 2014, 10:49:16 AM »
Found On the Road Dead, here.

I'm allowed to say that since I own one. Well, two actually -- I'm told my Mazda pickup truck is (besides the tractor).
I love it when a Plan B comes together!
Steve
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Offline mcostello

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Re: Brake caliper piston
« Reply #22 on: June 12, 2014, 11:22:37 AM »
Forked On Race Day.
High Speed steel in a Carbide world.

Offline dsquire

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Re: Brake caliper piston
« Reply #23 on: June 12, 2014, 12:31:22 PM »

 
               Fix Or Repair Daily    :lol: :lol: :lol:

Cheers  :beer:

Don
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Offline PekkaNF

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Re: Brake caliper piston
« Reply #24 on: June 12, 2014, 02:42:02 PM »
Very funny. I have heard most of those. Joke in Finland is that FORD stands for a chemical abreviation of rust! But I have had worse cars as well, one of them was Ford Taunus, other Morris Marina, then Saab turbo something (that catch fire on straight road), Citroen Xantia left me most balled, it's faults were either trivial or really exotic. Learned a lot from them. But biggest rust bait ever was one Toyota or Nissan, really can't decide, I welded several sqare meters of sheet metal on both of them.

Could this be contagious? Wife borrowed my big car and I got her latino audi (seat). Rear brake squaled once, I probably should have look of it also. Downer is that the rear brake is a drum brake. Ever pulled apart really well rusted and worn one?

Pekka