 oh, i got the rear brake caliper blues..., come, sing with me! |
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| red914 |
 Jan 11 2005, 11:33 PM
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#21
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...i believe in coyotes and time as an abstract...  Group: Members Posts: 862 Joined: 8-February 04 From: poulsbo, washington Member No.: 1,641  |
speaking for dino, perhaps out of place, the piston is slightly pitted and not wanting to come out of the cylinder. at all. so, if it is not mobile is it bad enough to be replaced?
hope that is what you would say dino. we never got to see any of your pistons on sunday, and only one of mine. |
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| Eric_Shea |
Jan 11 2005, 11:45 PM
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#22
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PMB Performance Group: Admin Posts: 19,275 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains  |
Well Dino... weigh in if you get a chance but, If it won't come out you'll probably want to scrap the caliper.
Here's what I'm thinking though... with a "regular" caliper it can be difficult to get the piston out, struggling back and forth between the two. With a 914 "rear" it should be "much easier". Those adjustment screws should literally "force" the piston out. No if ands or buts about it. If you're up against stripping out the adjustment allen heads then you may need to soak some more and apply heat. All of the seals you would need will come in a PP kit. You can hone the cylinder or even glass bead blast it (lightly) and you can use some 600 grit to polish the piston. The rubber seal that comes in the kit does all the... well... "sealing". If it's pitted too badly then replace. |
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| red914 |
Jan 12 2005, 09:04 AM
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#23
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...i believe in coyotes and time as an abstract... Group: Members Posts: 862 Joined: 8-February 04 From: poulsbo, washington Member No.: 1,641 |
jumping in again...
on both of my rears (the subject of this thread), the outer adjustment screws turn and turn and produce nothing. nadda. the inner screws are what loosened the piston that popped. the other one gets a bit of movement. but the outer adjustments get no result. prognosis, dr. brake? |
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| Eric_Shea |
Jan 12 2005, 10:39 AM
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#24
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PMB Performance Group: Admin Posts: 19,275 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
OK, I've got to ask a few questions to understand where you are with this. They might be rudementary but I need to know so, if I get too basic and offend don't go postal on me (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
1. Are you turning the adjuster itself (which is a 4mm allen screw in the center) or the 13mm lock nut? Simply loosen the 13mm and then turn the 4mm allen head center. A LOT of people turn the 13mm thinking it's the adjuster so I have to ask. 2. Are you turning them the right way? Outer screws need to be turned "counter clockwise" to force the piston out. Inner screws are turned clockwise. It sounds like yours were turned hard the "wrong" way initially and the adjuster screw is tightened into the inner piston mechanism. You may want to try a 4mm allen socket in reverse on an air wrench (high speed in reverse may break the bond). That being said; the inner piston mechanism will turn or spin with the adjustment screw if it is fused in there. About the only way it can get fused in there is if they were tightened the wrong way, run dry, sat forever or had water in the system causing rust. The system is usually filled with brake fluid which provides excellent protection from rust and corrosion. I agree with your earlier assumption, those calipers probably weren't even working. This should help answer your other question about an upgrade: I believe once you get your stock brakes back to the way they should be you will be mighty impressed, especially with a good set of pads. Options: If you are doing 1 and 2 properly and it is still spinning then I would say you "probably" have 1 option (maybe 2). Heat is where I would start. Here's how I would go about it: 1. Separate the caliper halves so you can work directly with the piston and adjuster in question. On early calipers you'll need a T27 Torx bit and an 11mm socket. On later calipers you'll need an 11mm socket. Remove the dust cover and clip and toss them. 2. Screw an additional 13mm nut over the end of the adjuster to protect it (let the nut overhang... does this make sense?) 3. Turn the assembly over and apply heat to the top of the piston. The adjustment screw is in the center of the piston. Use a MAP torch or regular propane but make sure you heat it up thoroughly. It will have to be "very" hot to get heat to the affected area. 4. On a hard surface tap the piston with the entire assembly resting in the 13mm nut you just installed. Don't whack it hard... just a bunch of light taps. It won't move. The taps are there to help break the bond. 5. Now, attempt to push the piston out using the 4mm wrench on the adjuster rotating counter clockwise. The heat may also help break the bond the piston has with the cylinder wall. There may be one other option to try before you get into the above proceedure. I have a grease gun that has a fitting that screws into the ATE fluid input. I use the grease with 120lbs. of air to remove pistons from standard calipers that are stuck. Again, your pistons will only "move" using this proceedure they will not come out (because the adjuster screws are still connected to them). If the pistons are bonded to the cylinder wall then this "may" help by breaking that bond. Grease is a fluid that won't compress. You can hook them up to your system as earlier mentioned if you don't have a grease gun but there's a bunch of variables like the proportioning valve etc. The proportioning valve "may" be your initial problem, not allowing enough movement (or any at all) to your rear pistons. If this is the case the "on car" pressure system may not work. Whew... I'm going back to bed. Good luck and let me know what you come up with. |
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| IronHillRestorations |
Jan 12 2005, 10:40 AM
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#25
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I. I. R. C. Group: Members Posts: 6,719 Joined: 18-March 03 From: West TN Member No.: 439 Region Association: None 
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The female part of the adjuster assembly, the part that's inside the piston, is turning. For the outboard adjuster, turning it clockwise should retract the piston in the bore. Use a clamp on the piston, and while under clamp pressure see if you can retract the piston with the adjuster screw. If you can get it to move, you can get it out. As suggested by someone else, you can try to turn the piston, but it's nearly impossible to do without chewing up the edge of the piston. You can turn the piston and gently pry up, but you pry too hard on the lip, you'll break it.
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| boxstr |
Jan 12 2005, 10:41 AM
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#26
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MEMBER:PACIFIC NORTHWEST REGION Group: Members Posts: 7,522 Joined: 25-December 02 From: OREGON Member No.: 12 Region Association: Pacific Northwest |
Hey how about making a phone call??
CCLINCANYOUHEARMEKNOW |
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| swood |
Jan 12 2005, 11:01 AM
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#27
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Senior Member Group: Members Posts: 1,839 Joined: 6-February 03 From: Strong Beach Member No.: 251 Region Association: None |
(IMG:http://www.914world.com/bbs2/html/emoticons/thisthreadisworthlesswithoutpics.gif)
Sorry, had to say it. Eric...why don't you help us all out since you're halfway through a "how to do it" thread and add pics for posterity's sake. (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif) This is very useful information and I appreciate you taking the time for it. Especially since I'm next! (IMG:http://www.914world.com/bbs2/html/emoticons/w00t.gif) |
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| drgchapman |
Jan 12 2005, 11:13 AM
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#28
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Current Stable Group: NoClassifiedAccess Posts: 922 Joined: 20-September 04 From: Portland, OR Member No.: 2,789 Region Association: Pacific Northwest |
Ok Eric, I'll bite. Where do I send my rear caliper for you to rebuild? As mentioned above, the inner adjuster (e-brake side) on this one just spins, no adjustment results.
I'll send once I know where. Gary |
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| dinomium |
Jan 12 2005, 11:23 AM
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#29
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Git on a chair son, all the good stuff is goin over yer head! Group: Benefactors Posts: 2,777 Joined: 2-January 03 From: Bremerton, WA Member No.: 74 Region Association: Pacific Northwest  |
I haven't retried mine, so they are still stuck. I was worried that if I took a pair of vise grips to the piston, I would chew them up badly.
Sorry for the high jack Shane SAN |
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| Eric_Shea |
Jan 12 2005, 02:42 PM
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#30
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PMB Performance Group: Admin Posts: 19,275 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
Say "please"... (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif) My hands have been too covered in brake fluid to be Mr. Photographer-Boy, besides f'n "Gint" will make fun of me if I post another "How-To" thread. (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif) All of which means... let me get this batch of calipers back from the plater and I'll get started on the photos. I may start a separete thread so as not to hijack this one. I'll throw a link in here for those interested.
Shea Suspension Services 10883 Pleasant Hill Drive Sandy, UT 84092 Gary, it may not be rebuildable. How soon do you need it? If I can work them without a core we can see if it's possible. If not, we'll have to get another core to work with. Shane and Dino, this may be your problem as well. Dino Don't try to pull it out with vise grips. You need to free up the adjuster screw. If that happens the piston will move. If you have broken the springs inside then you'll probably need new cores. I don't know of a supplier of these items. |
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| Gint |
Jan 12 2005, 05:55 PM
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#31
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Mike Ginter Group: Admin Posts: 16,075 Joined: 26-December 02 From: Denver CO. Member No.: 20 Region Association: Rocky Mountains |
NOW you're sensitive... Bring 'em on babe! (IMG:http://www.914world.com/bbs2/html/emoticons/thisthreadisworthlesswithoutpics.gif) |
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| Eric_Shea |
Jan 12 2005, 07:08 PM
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#32
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PMB Performance Group: Admin Posts: 19,275 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
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| red914 |
Jan 12 2005, 07:11 PM
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#33
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...i believe in coyotes and time as an abstract... Group: Members Posts: 862 Joined: 8-February 04 From: poulsbo, washington Member No.: 1,641 |
wow, Eric, you have given me a bunch of stuff to work with. let me go down to the garage and monkey around a bit. can't let this inspiration die!
by the way, i did loosen the lock nut and turn the 4mm allen screw, but, as dino will confirm, i am just the guy to think the lock nut was the deal! |
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| red914 |
Jan 12 2005, 07:39 PM
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#34
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...i believe in coyotes and time as an abstract... Group: Members Posts: 862 Joined: 8-February 04 From: poulsbo, washington Member No.: 1,641 |
harumph; still nuthin'. (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif) i'll keep at it. (IMG:http://www.914world.com/bbs2/html/emoticons/smash.gif) thanks for all the info and ideas.
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| Eric_Shea |
Jan 12 2005, 11:32 PM
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#35
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PMB Performance Group: Admin Posts: 19,275 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
Teaser... (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
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| Eric_Shea |
Jan 13 2005, 12:34 AM
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#36
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PMB Performance Group: Admin Posts: 19,275 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
Just thought of one other thing Shane...
If you can get your 13mm lock nut off those outer adjusters, you can use the grease gun method to push the outer pistons out. This will still leave you with only "one" (inner piston) to go. Buy a couple of cans of brake cleaner to get the grease off everything (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) |
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| drgchapman |
Jan 13 2005, 12:46 AM
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#37
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Current Stable Group: NoClassifiedAccess Posts: 922 Joined: 20-September 04 From: Portland, OR Member No.: 2,789 Region Association: Pacific Northwest |
Thanks for the address, Eric. I'll send caliper next week, going to whistler this weekend for some R&R. Those calipers of yours look great! (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/beer.gif)
Gary |
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| Eric_Shea |
Jan 13 2005, 12:53 AM
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#38
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PMB Performance Group: Admin Posts: 19,275 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
Never heard of Whistler... (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) You need to visit my backyard. (note the zip codes) (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) Thanks, send the caliper when you can (we have 35 year record snow BTW...) |
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| drgchapman |
Jan 13 2005, 01:07 AM
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#39
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Current Stable Group: NoClassifiedAccess Posts: 922 Joined: 20-September 04 From: Portland, OR Member No.: 2,789 Region Association: Pacific Northwest |
Yeah, Utah rocks for skiing, best powder on earth! Been many times, love it there. Whistler, BC. Usually rated best ski area in North America. Unlike the Wasatch, they know how to party..... (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/beer3.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/smoke.gif) So we are going for the skiing and the night life....if I can last that long.
Love the look of those calipers! Gary |
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| Eric_Shea |
Jan 13 2005, 08:57 AM
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#40
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PMB Performance Group: Admin Posts: 19,275 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
Got a point there... what's night life? (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif)
There's a pair with your name on them (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) |
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