How to take out front brake pads?

[bingo808]

Hi
Now tackling another issue.

I installed the rebuilt front forks yesterday - all good. (Although I did manage to mix up left and right forks, and soon realised my error when trying to install front mudguard!)

Now I would like to replace front pads as the front left pads have been soaked with fork fluid from the leaking left fork. I'll change the right side pads as well.

Can I salvage the old pads? Just asking to get people's opinions. But I have new pads so I want to put them in!!

But now I cannot undo a lock screw on the caliper. It's bloody tight. See image below.



Do I...
1. undo brake hose, mount the caliper in a vice and use an impact screwdriver to undo "grub" screw?
2. Persevere with an ordinary flathead and spray special anti-seize spray and leave for a while, then try again?

All advice appreciated.

[MacV2]

A/ new pads...

B/ Yeah take it off, clamp in vice, use Plus Gas, Try a flat bit from a socket set so you can use a bar to turn it...Bit of heat wont hurt either...

[bingo808]

Thanks for the tip, but I've got it sorted now.

Temporarily mounted the caliper back onto the fork leg. Then using all my strength (isn't much!) I managed to undo the grub screw both sides.

Removed centre pin and then pads. Installed new pads, then centre pin and spring clip thingy, then pushed back the pistons to account for the extra meat on the new pads.

Installed caliper back onto disc and fork. tightened bolts. All good. Now to bleed the brakes.

The old brake fluid was light brown(???) in colour. Ewwww.

[MacV2]

Thanks for the tip, but I've got it sorted now.

Temporarily mounted the caliper back onto the fork leg. Then using all my strength (isn't much!) I managed to undo the grub screw both sides.

Removed centre pin and then pads. Installed new pads, then centre pin and spring clip thingy, then pushed back the pistons to account for the extra meat on the new pads.

Installed caliper back onto disc and fork. tightened bolts. All good. Now to bleed the brakes.

The old brake fluid was light brown(???) in colour. Ewwww.

Half a job you should of stripped them down & cleaned the pistons up & checked the seals...

[bingo808]

Yeah, I know. That would of been best. But I can do that later. Just keen to get it registered!!

[rollingthunderx2]

I always use anti seize. I also have a parralel blade screwdriver I bought at a market years ago which fits perfectly, Ive never seen one since, and that was bought 21 years ago.

[IanB]

One of the probloems with this kind of job is that the screwdriver can slip out of the slot, thereby buggering up the slot and making further attempts at unscrewing even less likely to succeed. 1980's Japanese engine casing crosshead screws were famous for this.

I came across a product called Regrip about 25 years ago that totally fixed the problem. Here is what looks like an equivalent:

The stuff i have looks like grey grinding paste. you put a small drop on the screwdriver or in the slot, insert the screwdriver as normal and have at it. The only way I can descrribe it is it's as if someone just TIG welded the screwdriver to the screw. I thought it was snake medicine when I first saw it. I used it once, totally convinced. The screwdriver then just comes free as if the stuff's not there; wipe it off, done.

I think it's a suspension of tiny fragments of shattered tungsten carbide that dig into the tool & screwhead, sort of locking them together. Whatever it is, it works.

Ian

[sirch345]

I always use anti seize. I also have a parralel blade screwdriver I bought at a market years ago which fits perfectly, Ive never seen one since, and that was bought 21 years ago.

I never knew there was such a thing, I can imagine that being ideal for the screw on the brake calipers in question

One of the probloems with this kind of job is that the screwdriver can slip out of the slot, thereby buggering up the slot and making further attempts at unscrewing even less likely to succeed. 1980's Japanese engine casing crosshead screws were famous for this.

I came across a product called Regrip about 25 years ago that totally fixed the problem. Here is what looks like an equivalent:

The stuff i have looks like grey grinding paste. you put a small drop on the screwdriver or in the slot, insert the screwdriver as normal and have at it. The only way I can descrribe it is it's as if someone just TIG welded the screwdriver to the screw. I thought it was snake medicine when I first saw it. I used it once, totally convinced. The screwdriver then just comes free as if the stuff's not there; wipe it off, done.

I think it's a suspension of tiny fragments of shattered tungsten carbide that dig into the tool & screwhead, sort of locking them together. Whatever it is, it works.

Ian

That does sound like snake oil I agree, although seeing as you can vouch for it, it must work

Unless of course you're producing the stuff and selling it

Chris.

[IanB]

It's ok Chris, when the guy selling the stuff described it to me, that was my reaction too.

This was in Cairo, around 1997. He took an M8 crosshead screw, clamped it in a bench vice, gave me a screwdriver and said "rip the head to bits". Which I did - to the point where the screwdriver had virtually no grip, the screw was ruined. He then put a drop of this stuff on, said try again; I almost couldn't turn the screwdriver! I bought 4 bottles on the spot.

Now, when I suspect a screw is going to give problems, i use this stuff pre-emptively, and rarely have problems with stripped and cammed out screw heads.

Ian

[sirch345]

It's ok Chris, when the guy selling the stuff described it to me, that was my reaction too.

This was in Cairo, around 1997. He took an M8 crosshead screw, clamped it in a bench vice, gave me a screwdriver and said "rip the head to bits". Which I did - to the point where the screwdriver had virtually no grip, the screw was ruined. He then put a drop of this stuff on, said try again; I almost couldn't turn the screwdriver! I bought 4 bottles on the spot.

Now, when I suspect a screw is going to give problems, i use this stuff pre-emptively, and rarely have problems with stripped and cammed out screw heads.

Ian

Ian, please don't think I was doubting you, as I wasn't.
If there is a laughing emoji after any of my sentences, I am only joking

A good test that.
I'm really pleased you mentioning this product

Chris.

[IanB]

Nooo, it's ok Chris, I didn't think that! But it would have been very reasonable to; I knew the salesman well, I'd been going to his shop for a couple of years, he was one of very few honest salesman I met in Egypt (he was Armenina, real nice guy). When he showed me the stuff and said what it would do, I thought it was runny grinding paste.

Honestly, order a tube for your toolbox - you won't regret it.

[tony.mon]

I wonder if grinding paste would do the same job?

[IanB]

No, sadly, not in any way, shape or form. Different substance altogether.

Grinding paste is usually made of particles of aluminium oxide. When compressed hard, they shatter and turn into an even finer grinding paste. They're also not especially pointy.

This paste consists of tiny shards of tungsten carbide, which is harder than hardened steel (eg, screwdriver tips). It also has a very high compressive strength, making it ideal for lathe tool bits. When trapped between screw and driver, the carbide shards dig into both faces, which gives the grip.

It's notable that, even once you've wiped the screwdriver clean, use it on th enext screw without adding any more paste, and it's more effective than it was when you started out. Some of the particles seem to stay embedded for a while.

[sirch345]

Nooo, it's ok Chris, I didn't think that! But it would have been very reasonable to; I knew the salesman well, I'd been going to his shop for a couple of years, he was one of very few honest salesman I met in Egypt (he was Armenina, real nice guy). When he showed me the stuff and said what it would do, I thought it was runny grinding paste.

Honestly, order a tube for your toolbox - you won't regret it.

Chris.

[gilson]

I am genuinely amazed by this stuff. My father works on model steam engines, I wonder if he and his colleagues know of this stuff. Thank you.