front caliper re build Options

[solo1]

Guys I need help. I took the front left caliper off about a week ago to loosen it up as it was sticking, replaced pads. Drove the car it still got hot so the caliper is sticking. Rebuild kits arrived for all four corners. took same caliper off, pads out. Now what? if any one can give me or direct me to, a step by step way of re doing this I would really be grateful. Assume Im a "special needs" brake mechanic. I have always had some concern about brakes cause it has to be done right. I keep staring at the caliper thinking this cant be that tough have one side piston secured with a C clamp and block. Thats as far as Ive gotten. Thinking I may be in too deep and am considering taking them to a shop and having them to the re build with the fresh parts.

[underthetire]

Just did mine Last weekend, Fronts are easy. Rears not so much. First thing you need to do is get the pistons out. Remove your clamp, and with compressed air blow in the brake line fitting. One piston should blow out. Split caliper and you will see the two fluid holes, one on each side. Grab the side that still has the piston in it, and clamp in in a vise with a soft piece of plastic covering one hole and the mating surface on one side. Do not gouge the machined surface! Blow air in the free hole now, and you may have to gently pry the piston out at the same time with a screwdriver. A word of caution, the piston will fly in to the front of your car and dent it if pointed towards your car (IMG:style_emoticons/default/biggrin.gif) . Brake fluid will be everywhere, so be prepared. I use a brake hone to clean up the bores, just a swipe or two will do it, just to get the varnish off. Clean the pistons with 600 sandpaper, clean everything very well. Re-assemble using brake fluid only. I hope you didn't buy EBAY re-build kits, they do not have everything you need.

Rears are almost the same, but the adjusters and adjuster snap rings are a real PIA if you've never done them. And if the Ebrake arm area needs rebuilding to, might as well just send them to PMB.

[solo1]

Just did mine Last weekend, Fronts are easy. Rears not so much. First thing you need to do is get the pistons out. Remove your clamp, and with compressed air blow in the brake line fitting. One piston should blow out. Split caliper and you will see the two fluid holes, one on each side. Grab the side that still has the piston in it, and clamp in in a vise with a soft piece of plastic covering one hole and the mating surface on one side. Do not gouge the machined surface! Blow air in the free hole now, and you may have to gently pry the piston out at the same time with a screwdriver. A word of caution, the piston will fly in to the front of your car and dent it if pointed towards your car (IMG:style_emoticons/default/biggrin.gif) . Brake fluid will be everywhere, so be prepared. I use a brake hone to clean up the bores, just a swipe or two will do it, just to get the varnish off. Clean the pistons with 600 sandpaper, clean everything very well. Re-assemble using brake fluid only. I hope you didn't buy EBAY re-build kits, they do not have everything you need.

Rears are almost the same, but the adjusters and adjuster snap rings are a real PIA if you've never done them. And if the Ebrake arm area needs rebuilding to, might as well just send them to PMB.

thank you just printed it out. did not get re build kits from ebay, got em from Pelican.

[Ericv1]

Guys I need help. I took the front left caliper off about a week ago to loosen it up as it was sticking, replaced pads. Drove the car it still got hot so the caliper is sticking. Rebuild kits arrived for all four corners. took same caliper off, pads out. Now what? if any one can give me or direct me to, a step by step way of re doing this I would really be grateful. Assume Im a "special needs" brake mechanic. I have always had some concern about brakes cause it has to be done right. I keep staring at the caliper thinking this cant be that tough have one side piston secured with a C clamp and block. Thats as far as Ive gotten. Thinking I may be in too deep and am considering taking them to a shop and having them to the re build with the fresh parts.

As he said be careful when blowing the pistons out. Make sure no body parts are in the way as it will hurt. What part of Cincy you from? There's not too many teeners around here.

[Eric_Shea]

***IMPORTANT***

I don't recommend anyone use Jeff's method of rebuilding a front caliper. It's very dangerous and, the screwdriver trick is what's damaged "many" 914 front pistons. (Sorry Jeff)

DO NOT seperate the caliper 1/2's before the second piston has been removed. A long steel plate the width of the cavity and a rubber washer from Lowes/McMaster-Carr is a "much" safer bet. Pad the cavity with a shop rag and blow the inner piston out first by clamping off a corner of the outer piston. Then position the rubber washer over that bore. Use the vise to clamp the bottom of the steel plate with the caliper mounting ears and a couple of c-clamps for the top. This will hold the rubber washer over the bore and seal it off. Again, pad the piston cavity so you do not break the tops of the pistons. Use air. If you need to use a screwdriver to get the piston out... don't; move to fluid at that point. A cheap grease gun from HF will work. Remove the nozzle and you will be left with a 10x1 fitting that will screw right into your caliper. Fluid does not compress and the resulting effect will be a piston that simply "plops" out onto your bench.

Air compressed in a caliper 1/2 pointing ??? in the garage can net a piston flying out of a bore at the velocity of a bullet. You decide if that's a good/safe thing.

Personally, I don't use compressed air anymore on 914 front pistons. They are too fragile. I have a special water pump made up to pump pistons out... that said, this is still something you can do at home with a grease gun. It will just be messy to clean up (use brake cleaner and compressed air).

Do not use 600 grit on your pistons. 0000 steel wool is most accessable. A bench top buffer is preferred. Those sides are a sealing surface and, you can risk mis-shaping them with too much grit. I've used 600 in the past and I agree... this is picking-nits, you can use it but go with very light pressure and wrap the 600 around the piston. It's just easier and better with the steel wool.

Wire brush on a drill is good for cleaning the tops (not the sides), then use a heat paint to coat the piston tops (muffler paint or POR-20)... brakes get hot.

Not a fan of honing bores anymore either... this leaves a fresh steel on steel surface where rust can develop. They make brake cylinder hones, I've used them in the past but, not my favorite thing moving forward.

I'm a big fan of taking these caliper 1/2's to a local plater. Usually, for around $20.00, you can go to your local plater (Google is your friend) get a fresh coat of yellow zinc, just like ATE did. The process of cleaning and etching will clean the bores and you will be left with a nice coating of zinc there. The bore is not your sealing surface... the seal and the piston is.

Hope this helps.

[Krieger]

Eric, when doing a front pair of calipers do you bother getting each piston back to its original location?

[underthetire]

Thats why your the "expert"! (IMG:style_emoticons/default/biggrin.gif) I could see the screwdriver thing damage a piston, but with a little back pressure and a gentle nudge with the screwdriver, mine came out with zero damage. They do come out pretty fast though once they start moving.

[Eric_Shea]

Eric, when doing a front pair of calipers do you bother getting each piston back to its original location?

Absolutely. The late model kits come with positioners which I recommend you install before re-loading the pistons.

1. Clean/Restore pistons.
2. Install dust seal
3. Install positioners
4. Lubricate underside of dust seal (late model fronts only)
5. Install pistons

There's a trick for those that don't come with positioners as well. Draw an imaginary center line down the cavity and place the bottom notch of the piston step along this line. This will ensure a 20 degree alignment in the face of the on-coming rotor.

Now, if you're asking if I put the left outer piston back where it was in the caliper, etc.? No.

[tat2dphreak]

or be 100% sure and just use your calipers as cores for Eric... I did this and have never regretted having 4 great looking, great stopping brakes with porterfield pads...

the car stops on a dime.

[solo1]

Guys I need help. I took the front left caliper off about a week ago to loosen it up as it was sticking, replaced pads. Drove the car it still got hot so the caliper is sticking. Rebuild kits arrived for all four corners. took same caliper off, pads out. Now what? if any one can give me or direct me to, a step by step way of re doing this I would really be grateful. Assume Im a "special needs" brake mechanic. I have always had some concern about brakes cause it has to be done right. I keep staring at the caliper thinking this cant be that tough have one side piston secured with a C clamp and block. Thats as far as Ive gotten. Thinking I may be in too deep and am considering taking them to a shop and having them to the re build with the fresh parts.

As he said be careful when blowing the pistons out. Make sure no body parts are in the way as it will hurt. What part of Cincy you from? There's not too many teeners around here.

Im in maineville actually north of kings island.

[solo1]

thanks you guys will try it this weekend. taking the caliper off and disconnecting the brake line i need a fitting that goes into the brake fluid port on the caliper and attach it to the air compressor what size should the fitting be that attaches to the brake fluid port. next the seal that goes around the piston has a split ring holding the seal in place , the seal is shot will i still be able to blow out the piston? or am I "fuched"?

[underthetire]

thanks you guys will try it this weekend. taking the caliper off and disconnecting the brake line i need a fitting that goes into the brake fluid port on the caliper and attach it to the air compressor what size should the fitting be that attaches to the brake fluid port. next the seal that goes around the piston has a split ring holding the seal in place , the seal is shot will i still be able to blow out the piston? or am I "fuched"?

The split ring only holds the dust cover on. The seal is internal. I just used a blow gun with no fitting. Mine popped out pretty easy. Your re-build kit should have 2 internal piston seals, two dust covers, two metal retaining rings, 2 piston anti-rotaion shims, and a new plate with tabs for the mounting bolts. The kits I got from eric even had new mounting bolts. You may want to get the caliper o-ring seals for the body to put it back together with to, even my kits I got from eric were missing them, but he mailed them to me.

[solo1]

thanks you guys will try it this weekend. taking the caliper off and disconnecting the brake line i need a fitting that goes into the brake fluid port on the caliper and attach it to the air compressor what size should the fitting be that attaches to the brake fluid port. next the seal that goes around the piston has a split ring holding the seal in place , the seal is shot will i still be able to blow out the piston? or am I "fuched"?

The split ring only holds the dust cover on. The seal is internal. I just used a blow gun with no fitting. Mine popped out pretty easy. Your re-build kit should have 2 internal piston seals, two dust covers, two metal retaining rings, 2 piston anti-rotaion shims, and a new plate with tabs for the mounting bolts. The kits I got from eric even had new mounting bolts. You may want to get the caliper o-ring seals for the body to put it back together with to, even my kits I got from eric were missing them, but he mailed them to me.

i got the parts from pelican it appeared to have everything you mentioned thank you was spazzing on the outside ring being gone thought the seal was blown so there was no way to get the piston out. You guys really rock Im a newbie at this but am determined to do as much of this stuff without farming it out. seriously thanks to every one of you guys.

[biggy72]

So I've got 4 VERY stuck calipers. I'm trying to get the pistons out, but nothing seems to work like it did for the people above. I haven't tried to adjust the rears out yet, but the fronts won't move. I took the dust covers off and sprayed some penetrant fluid around the pistons, but is there a good way to get them out?

[Eric_Shea]

Fluid is probably the only way at this point. I know what you're saying because I see it almost daily. You can:

1. Put them back on the car and try to pump them out that way. You might be able to get them out far enough where air will work.

2. Get a cheap ($13.00) grease gun and remove the tip. You will be left with a 10x1 end that will screw into the caliper. Grease, being a fluid, will not compress and the piston will plop out. Follow the instructions above for the second bore.

3. Devise a water pump. This will be easier to clean up but more difficult to fabricate.

Tip: Not sure about the laws in WA but here on Planet Utah we can still buy the Gunk carb cleaner by the gallon. You might try soaking them in there for a couple days and try air again.

Tip: Using a large C-Clamp, push them back in. This can break the bond of piston and bore and they "might" come out with air.

Tip: You can try heating the calipers outer surface with a MAPP torch. That may also help break the bond of piston and bore and they "might" come out with air.

Tip: You might try brake cleaner around the pistons and into the fluid inlet. This may break that bond and they "might" come out.

Bottom line though... a proper fluid extraction will work wonders and keep both the caliper and piston in good order.
________________________________________________________

Regarding ther rears.... here's a few more tips:

Tip: Move the handbrake arm before attempting to remove the inner piston. Even if you have to tap it with a hammer (WATCH THE SPRING PIN AND DON'T TAP TOO HARD!!!). By moving the arm you will move the piston about 1/8th inch and break that bond and the piston should come out much easier.

Tip: Use an air wrech to power out the inner piston after you move the handle back. Watch the handle move forward, pull it back again and do it all over again. This put minimal strain on that inner adjuster. You're basically using the handbrake arm to push out the piston.

Tip: Take the clip and the 13mm locking nut off the outside adjuster and lightly tap the entire thing out. Use a plastic mallet if possible so as not to distort the 4mm hex. Once the hex becomes flush with the caliper, use a 4mm bit and bring it back up to the top. Rinse and repeat. This will literally tap the piston out without damaging the fragile 4mm hex (unless you wack it too hard)

Did I mention that fluid is probably the only option at this point? (IMG:style_emoticons/default/biggrin.gif) They can be saved.

[biggy72]

I tried some heat tonight. I got the inners pushed most of the way out on the rear, but I'll have to give the e-brake arm a try.

I'll try tapping on the outters for the rear. I had it pushed out, but it wasn't going anywhere. I guess I didnt' see that it should be tapped in and done over again.

I'll also give the grease gun a shot tomorrow. I figured I couldn't be the first person that couldn't get the pistons out that easy, but it seems like most of the people I read about just have them slide right out.

Thanks for the help

[Eric_Shea]

I got the inners pushed most of the way out on the rear, but I'll have to give the e-brake arm a try.

If they're pushed most of the way, they are probably off the adjusters now. You may be able to rock them out. I have special cutouts in the ends of my vise to grab the piston head without damaging the dust seal ridges.

it seems like most of the people I read about just have them slide right out

If the caliper is working on the car at the time of removal/restoration they generally just pop right out using air. If the car has sat for a long period of time... most are in your boat.

NOTE: Do not use fluid or air on the rears. They simply adjust out. Only in extreme cases have I used fluid on the rears and this is to literally blow the piston off the internal adjusting mechanism. This is only when the inner adjuster does not turn using the gear... very extreme and rare circumstances and very extreme measure. ONLY USE FLUID AND AIR ON YOUR FRONT CALIPERS.

[solo1]

consider me brain dead. spent a while working on caliper last night to blow out the piston. First used a block of wood and C clamps to apply pressure to move piston in and out make sure it wasnt seized, they flexed a little bit not sure how much movement should be in there.

newbie question: how do i block the bleeder valve or the bleeder valve hole to prevent the pressurized air from escaping? should this be this difficult or am i just encountering newbie-itis?

[Mikey914]

Eric did a rebuild demo at WCR, it quickly was apparent that if your doing a single set of your own, it was probably much easier to just send him a core set and swap them out.

[solo1]

Eric did a rebuild demo at WCR, it quickly was apparent that if your doing a single set of your own, it was probably much easier to just send him a core set and swap them out.

eric shea in UTAH? got an e mail or contact number, thanks