RC51 Forums banner

1 - 20 of 20 Posts

·
Registered
Joined
·
139 Posts
Discussion Starter #1 (Edited)
Hi everyone,

I have the classic "how the eff" question for stubborn threads, hoping our experts here can give me pointers on how they got them loose.

First one is the forward screw on the throttle tube housing, I was gonna install my shiny new HRC throttle tube. The one screw came out without a fight, the second screw would rather sacrifice itself than be removed from its home. I tried every screwdriver that would fit (both phillips and flat-head), tried tapping on said screwdrivers to get the threads to loosen, tried anti-sieze spray, etc etc etc. Nevertheless, it ain't comin out. I'm afraid the only way to back it out will be to use a Dremel to cut a wide groove and use a big screwdriver. Any ideas? This is the screw I mean:



The second problem is with the rear caliper. I just wanted to replace the pads, but I can't get the mounting pin out. Service manual says that the thing that looks like a shallow flat-head screw is a plug. How's it come out? Sounds dumb, I know, but I even had a wrench on the screwdriver, and still couldn't back it out. Either I'm making some dumb mistake, or that plug is good n' frozen.
Here's what I mean:



Any advice is appreciated, thanks guys!
 

·
Registered
Joined
·
729 Posts
for the twist grip housing screw use a pin punch (or an old 3/8 extension) and give it a good sharp hit with a hammer on the top of the screw, this will do two things, the first being to hopefully break the thread to loosen up, the second making your cross head screwdriver be a nice snug fit again
tap the screwdriver into the screw and if it a nice tight fit start to put a bit of strength into turning it whilst hitting the screwdriver with a hammer
Yes i know you can use an impact driver but they lack the feel of my method, i have seen (and repaired) many broken things that people have attempted to undo with an impact driver.
The same method will work on the rear caliper, just make sure you have a good fitting screwdriver
 

·
Registered
Joined
·
120 Posts
I always use an impact driver, if you don't twist it while you hit it less things break, let it do it's job... Saved my life a million times especially on older bikes that use phillips to hold the cases together...

If it is really stuck, I hold the ball end of a ball peen hammer against the screw and hit the back of the hammer with another hammer.... then try again with the impact driver...

http://buy1.snapon.com/catalog/item.asp?item_ID=631500&group_ID=674820
 

·
Registered
Joined
·
729 Posts
I always use an impact driver, if you don't twist it while you hit it less things break, let it do it's job... Saved my life a million times especially on older bikes that use phillips to hold the cases together...

If it is really stuck, I hold the ball end of a ball peen hammer against the screw and hit the back of the hammer with another hammer.... then try again with the impact driver...

http://buy1.snapon.com/catalog/item.asp?item_ID=631500&group_ID=674820
You should never hit a hammer with another hammer ball pein or otherwise
 

·
Registered
Joined
·
162 Posts
I'd try tightening the screw first, other than that its an impact driver I'd be looking at using, usually brute force and ignorance can be your freind
 

·
Premium Member
Joined
·
736 Posts
You should never hit a hammer with another hammer ball pein or otherwise
meh...

http://mythbustersresults.com/episode67

If two hammers strike each other, at least one of them will completely shatter with lethal force.
BUSTED
Using a custom rig, the MythBusters repeatedly struck pairs of hammers together, but none shattered. Hammers with wooden handles merely snapped in two and hammers with metal handles bent. The MythBusters then decided to make the steel hammers harder and more brittle by adding more carbon and through heat treatment. In particular, they attempted to case harden the hammers, however it is questionable if this was done correctly. They heated the hammers to high temperatures and then coated the hammer heads in used engine oil. They also decided to have the hammers strike a more sturdy anvil instead of each other. However, during testing, the carbonized hammers merely bent at the handles without shattering. Furthermore, an anvil is generally not made of particularly hard steel, and so that test may have been doomed from the beginning. An anvil with a hardened tool steel insert would have been more appropriate. Though the myth was busted, some hammers come with warnings not to use them to strike another tool or hardened nail with excessive force; although no hammerhead shattered or chipped, high-speed footage showed particle dust flying in all directions, which presents an eye hazard.
 

·
Registered
Joined
·
729 Posts
meh...

http://mythbustersresults.com/episode67

If two hammers strike each other, at least one of them will completely shatter with lethal force.
BUSTED
Using a custom rig, the MythBusters repeatedly struck pairs of hammers together, but none shattered. Hammers with wooden handles merely snapped in two and hammers with metal handles bent. The MythBusters then decided to make the steel hammers harder and more brittle by adding more carbon and through heat treatment. In particular, they attempted to case harden the hammers, however it is questionable if this was done correctly. They heated the hammers to high temperatures and then coated the hammer heads in used engine oil. They also decided to have the hammers strike a more sturdy anvil instead of each other. However, during testing, the carbonized hammers merely bent at the handles without shattering. Furthermore, an anvil is generally not made of particularly hard steel, and so that test may have been doomed from the beginning. An anvil with a hardened tool steel insert would have been more appropriate. Though the myth was busted, some hammers come with warnings not to use them to strike another tool or hardened nail with excessive force; although no hammerhead shattered or chipped, high-speed footage showed particle dust flying in all directions, which presents an eye hazard.
You live and learn, this was something i was told nearly 40 years ago whilst doing my apprenticeship, maybe it was an evil rumour, maybe the hammers were made different :eek:
 

·
Registered
Joined
·
139 Posts
Discussion Starter #10 (Edited)
usually brute force and ignorance can be your freind
Very well stated, my friend :cool: I had an impact driver at one point in time, I may have given it to a friend before I packed up and moved to Europe, completely forgot about that option. I'll see if I can find one here.

I'll also try a dose of excessive force on the throttle screw, I wasn't sure just how hard one can hammer on the clip-on assembly, but in any case as a result of varied attempts the screw is pretty well chewed up. I tried tapping odd-size drivers into it, but maybe I just needed one I happened to not have. Absolute worst case I can dremel the head off completely and slide the housing off. Gotta replace the screw anyway, I just didn't want a 30-minute job to require a MacGuyver.

As for the caliper plug, seriously, I've rapped on it hard enough to be concerned for the sake of the caliper itself and its mounting bracket, and have pushed on the screwdriver (while turning it) hard enough that I had a friend sit on the bike so it wouldn't move. I think I'm gonna have to resort to taking the caliper completely off and putting it in a vice, maybe even have to cut the groove deeper. I don't understand what that plug is doing there in the first place, none of the other brake system pins have plugs in them. Oh well, I should bleed the brake circuit anyway.

Thanks for the input, guys!
 

·
Premium Member
Joined
·
4,617 Posts
When you put new screw / insert back in, it's good to coat the threads with a little copper grease so they won't seize again.
 

·
Super Moderator
Joined
·
6,481 Posts
On the caliper, it's a grub screw that secures the pad pin in place.
Since both it and pin are steel, plus the guide pin the caliper slides, and mounting bolt (it's single-action caliper), they are prone to corrosion. As I found on mine.

Also road grime, water, and brake dust can bet around the rubber boots and into guide pin hole, causing the caliper to not release properly, with one or both pads getting prematurely worn.

For me, I replaced the pad pin, grub screw, guide pin, and bolt with titanium to avoid corrosion.
Otherwise, Pro-Bolt also makes much less expensive stainless replacements as well.

Then while I had the caliper dismounted, I cleaned out threads and old grease on the guide pin hole, then greased and assembled.
 

·
Registered
Joined
·
120 Posts
You should never hit a hammer with another hammer ball pein or otherwise
I've heard this, didn't believe it. I do it every time I do brakes (daily) twice on each rotor. Same two hammers going strong for some time. The guy who taught me the trick is still alive and still wrenching after 35 years of doing it.


Starting out if you use the right bit, give a quick tap before you start, and use the impact driver it'll come. Especially on throttles for some reason, I've made it a habit to start with the impact instead of mucking up the head trying to get it off first.
 

·
Premium Member
Joined
·
8,335 Posts
When you put new screw / insert back in, it's good to coat the threads with a little copper grease so they won't seize again.
+1 or use some graphite, either works well when you have two different metals fastened together.

As for your Philips head issue take the best fitting screw driver you have, once inserted pop it with a mallet or a hammer to help seat the screw driver into the boogered up screw. Concentrate your force when loosening straight dwn and avoid angling the screw driver.

Good luck to you.:cool:
 

·
Registered
Joined
·
162 Posts
You should never hit a hammer with another hammer ball pein or otherwise
meh...

http://mythbustersresults.com/episode67

If two hammers strike each other, at least one of them will completely shatter with lethal force.
BUSTED
Using a custom rig, the MythBusters repeatedly struck pairs of hammers together, but none shattered. Hammers with wooden handles merely snapped in two and hammers with metal handles bent. The MythBusters then decided to make the steel hammers harder and more brittle by adding more carbon and through heat treatment. In particular, they attempted to case harden the hammers, however it is questionable if this was done correctly. They heated the hammers to high temperatures and then coated the hammer heads in used engine oil. They also decided to have the hammers strike a more sturdy anvil instead of each other. However, during testing, the carbonized hammers merely bent at the handles without shattering. Furthermore, an anvil is generally not made of particularly hard steel, and so that test may have been doomed from the beginning. An anvil with a hardened tool steel insert would have been more appropriate. Though the myth was busted, some hammers come with warnings not to use them to strike another tool or hardened nail with excessive force; although no hammerhead shattered or chipped, high-speed footage showed particle dust flying in all directions, which presents an eye hazard.
I'd probably still take note on the advice about not hitting hammers off each other, not from a "tool breaking" point of view but more from a "breaking your face" point of view as a hammer can bounce back pretty hard when hit off of a similarly hardened tool surface, especially if you ain't expecting it to do that and you give it a bit of ooomph

all in perspective of course, as i was actually doing this last week with a ball pein and a claw hammer to flatten out some metal on the race can I'm repairing, using the 2 faces like a planishing hammer
 

·
Registered
Joined
·
139 Posts
Discussion Starter #18
Hi everyone,

I eventually won over the stuck rear caliper plug, I used a flat-head punch and small hammer, and had a friend turn the punch (put a wrench on it) while doing so. Amazing that such a seemingly insignificant component could be such a pain in the arse. Anyway, after that the brake pad swap took five minutes, the brake pad pin came out with no problem at all, and I did coat the threads of the pin and the plug with anti-sieze.

Haven't gotten to the throttle housing screw yet, but as mentioned, I think I'm just gonna grind the screw head off completely, and slide the housing half off that way.
 

·
Registered
Joined
·
8,663 Posts
Have you considered using tamper-proof bolt extractors?
I just bought a set yesterday to remove the bolts on the underside of the top clamp, the ones that hold the ignition.
 

·
Registered
Joined
·
355 Posts
Now Im the king of screwing up screws lol, personally what I found works good and simple is whack it a few times to loosen it up then go get yourself a left handed drill bit DO NOt use any cutting oil once the bit bites the screw should just back out. Then you can get the screw off the bit with some pliers.

Hope this helps I hate stubborn screws.
 
1 - 20 of 20 Posts
Top