Lima Delta Posted May 2, 2022 Share Posted May 2, 2022 Hey guys, It started last year when I heard some grinding and rattling coming front the front right while driving. Pulling the wheel off, the brake caliper had come loose after the retaining key had somehow started working its way out of it's slot. The key can't fall out completely because it's ultimately contained by the wheel, however it did contact the back side of the wheel (grinding noise). Anyhow... I put everything back together using a new key, spring and retaining bolt. A few days later it came loose again while driving. I put everything back together and played with the caliper and it seemed like there was some excessive up/down play in the assembly, which might have let the slot in the key jump over the retaining bolt.... I took another spring, trimmed the ends off and ground it down al little then inserted it as a shim under the existing spring. That seemed to fix the problem, and I haven't had any trouble with it for months but then this morning it happened again. Nothing seems to have changed since my last repair. With the shim in between the spring and the key there doesn't seem to be any up/down play in the caliper assembly. The retaining bolt doesn't seem to have backed out, but somehow the notch in the key is managing to slide past the retaining bolt... Any insight as to what might be going on here? Link to comment Share on other sites More sharing options...
grumpin Posted May 2, 2022 Share Posted May 2, 2022 Wheel bearing loose? You’ve done a good job with it. Sometimes you get strange problems. Link to comment Share on other sites More sharing options...
Lima Delta Posted May 2, 2022 Author Share Posted May 2, 2022 Wheel bearing loose? I'm wondering about that too. I'm not getting any noise and there doesn't seem to be any play in the hub though... I'll have to have a closer look. One thing I just thought of is that since I repaired it last, I'm pretty sure I've been driving around with the hubs locked full-time (which I normally do in winter). The other day I unlocked the hubs for the first time since and it was shortly after that the problem recurred. Think that could that have something to do with it? Link to comment Share on other sites More sharing options...
FuzzFace2 Posted May 2, 2022 Share Posted May 2, 2022 Wheel bearing loose? I'm wondering about that too. I'm not getting any noise and there doesn't seem to be any play in the hub though... I'll have to have a closer look. One thing I just thought of is that since I repaired it last, I'm pretty sure I've been driving around with the hubs locked full-time (which I normally do in winter). The other day I unlocked the hubs for the first time since and it was shortly after that the problem recurred. Think that could that have something to do with it? There is no way I can see the hubs being locked or un-locked to be the cause. If so it would be happening to a lot of trucks. I have to ask a stupid question are you sure you are installing the spring on the right side of the key? The spring should go on the side away from the bolt so the spring is pushing the key to the bolt. I would also say once put back together try using a hammer & punch to push the key out to see if you can see what might be happening. Is this on a 250 truck and have dual piston calipers? Was the caliper replaced not long ago? I want to say I remember reading something (other forum?) about caliper(s) falling off. Dave ---- Link to comment Share on other sites More sharing options...
Rembrant Posted May 2, 2022 Share Posted May 2, 2022 I know on my F150 when I did mine with a new hardware kit (and new calipers), I had to tap/hammer that piece in there, there was that much tension on the spring. That was lubed up, too. If I had to guess, I'd say that the caliper opening is getting bigger, if that makes any sense... The forward force of the caliper is wearing on the spindle? I dunno. The cheap fix...if you're into that sort of thing...lol, is to weld some tabs on each side of that little opening that fits around the bolt, essentially making it impossible for it to "jump" the bolt. That's what I'd do at least...it's a cheap throw away part anyway. (I get it though...some people are not into welding on or modifying brake parts, but you did double shim it, so you have at least some tolerance for this type of shenanigans...lol). PS: Stupid question...you do have the correct type of bolt in there right? It has a big shoulder on it where it fits in the little curved opening. Link to comment Share on other sites More sharing options...
Lima Delta Posted May 3, 2022 Author Share Posted May 3, 2022 There is no way I can see the hubs being locked or un-locked to be the cause. If so it would be happening to a lot of trucks. I have to ask a stupid question are you sure you are installing the spring on the right side of the key? The spring should go on the side away from the bolt so the spring is pushing the key to the bolt. I would also say once put back together try using a hammer & punch to push the key out to see if you can see what might be happening. Is this on a 250 truck and have dual piston calipers? Was the caliper replaced not long ago? I want to say I remember reading something (other forum?) about caliper(s) falling off. Dave ---- Dave, yeah, I made double sure that the spring is on the right side of the key. That's definitely a mistake that could be made, but it's good. It is a 4x4 F250 with the dual piston calipers which are original as far as I know... at least they are old enough that I had to replace the bleeder screws a little while back as they were totally seized. I was wondering if new calipers might correct the problem, but I can't see how the fit would really be any different.... I did a search already about "loose" calipers, I guess i'll try again looking for hits about them falling off lol Lucas Link to comment Share on other sites More sharing options...
Lima Delta Posted May 3, 2022 Author Share Posted May 3, 2022 I know on my F150 when I did mine with a new hardware kit (and new calipers), I had to tap/hammer that piece in there, there was that much tension on the spring. That was lubed up, too. If I had to guess, I'd say that the caliper opening is getting bigger, if that makes any sense... The forward force of the caliper is wearing on the spindle? I dunno. The cheap fix...if you're into that sort of thing...lol, is to weld some tabs on each side of that little opening that fits around the bolt, essentially making it impossible for it to "jump" the bolt. That's what I'd do at least...it's a cheap throw away part anyway. (I get it though...some people are not into welding on or modifying brake parts, but you did double shim it, so you have at least some tolerance for this type of shenanigans...lol). PS: Stupid question...you do have the correct type of bolt in there right? It has a big shoulder on it where it fits in the little curved opening. Hi Cory, Ok, my left side caliper has about the same kind of fit where the key and spring need to be tapped in with a hammer. Seems odd to me that the fit on the other side is so different! The shim that I added takes all the play out of the caliper, but it's still possible for me to cajole the key and spring in by hand. Welding the key is something I hadn't considered, but I'll consider it now lol! The bolt is the correct one with the bulge just under the cap flange. I had also been considering making my own bolt with a bigger "bulge"... In either case, I'd still like to understand what the cause is. Again, it seems odd that there would be wear on these parts that would cause that much play between them... Maybe the spindle got bent out of shape somehow? Lucas Link to comment Share on other sites More sharing options...
85lebaront2 Posted May 3, 2022 Share Posted May 3, 2022 I had to do some digging, Ford changed the caliper design and mounting between 1985 and 1986. Darth uses two strange split pins with rubber between them, I remember dealing with the retention system you have on my 1977 F150 and possibly on some of my big Ford cars. The only things I can come up with as a reason, would be (a) caliper is either worn a lot where it slides on the bracket or (b) bracket is worn or bent so the fit is loose. The only way I can think of to determine which is the cause will involve a bit of measuring. The width of both the caliper slide areas and the spacing of the caliper mounting bracket will need to be determined. Unfortunately, I imagine the caliper mount is part of the spindle and not removable like a 2WD generally is. If it is removable, I would try (even though it will be a pain) checking the fit on the opposite side caliper to see if there is a difference in the fit. Link to comment Share on other sites More sharing options...
FuzzFace2 Posted May 3, 2022 Share Posted May 3, 2022 I know on my F150 when I did mine with a new hardware kit (and new calipers), I had to tap/hammer that piece in there, there was that much tension on the spring. That was lubed up, too. If I had to guess, I'd say that the caliper opening is getting bigger, if that makes any sense... The forward force of the caliper is wearing on the spindle? I dunno. The cheap fix...if you're into that sort of thing...lol, is to weld some tabs on each side of that little opening that fits around the bolt, essentially making it impossible for it to "jump" the bolt. That's what I'd do at least...it's a cheap throw away part anyway. (I get it though...some people are not into welding on or modifying brake parts, but you did double shim it, so you have at least some tolerance for this type of shenanigans...lol). PS: Stupid question...you do have the correct type of bolt in there right? It has a big shoulder on it where it fits in the little curved opening. Hi Cory, Ok, my left side caliper has about the same kind of fit where the key and spring need to be tapped in with a hammer. Seems odd to me that the fit on the other side is so different! The shim that I added takes all the play out of the caliper, but it's still possible for me to cajole the key and spring in by hand. Welding the key is something I hadn't considered, but I'll consider it now lol! The bolt is the correct one with the bulge just under the cap flange. I had also been considering making my own bolt with a bigger "bulge"... In either case, I'd still like to understand what the cause is. Again, it seems odd that there would be wear on these parts that would cause that much play between them... Maybe the spindle got bent out of shape somehow? Lucas Try this link https://www.ford-trucks.com/forums/1498309-brake-caliper-falls-off-1981-f-250-dual-piston-caliper.html Here is the search link if it comes up https://www.ford-trucks.com/forums/search.php?searchid=32536833 Dave ---- Link to comment Share on other sites More sharing options...
Lima Delta Posted May 4, 2022 Author Share Posted May 4, 2022 The only things I can come up with as a reason, would be (a) caliper is either worn a lot where it slides on the bracket or (b) bracket is worn or bent so the fit is loose. The only way I can think of to determine which is the cause will involve a bit of measuring. The width of both the caliper slide areas and the spacing of the caliper mounting bracket will need to be determined. Yes, I'm thinking I'm going to have to try to "blueprint" the brackets as best I can. Seems more likely that the problem is with the caliper, but I'd like to know for sure before I spend any money on parts. Link to comment Share on other sites More sharing options...
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