cant get caliper bolts loose on rear ??

[t5tart]

Originally Posted by egremont

What about trying a hand held IMPACT DRIVER WRENCH?
These are used in motorcycle workshops to undo very tight bolts.
One of these tools is shown in this YouTube.

https://www.youtube.com/watch?v=cUSuSn_QZmk

Don’t be scared to tap the wrench with a 1.3 Kg club hammer – the added force helps.


A manufacturer describes it better than me. This hand tool is used to unscrew bolts that may have become rusted into place. One end has a 3/8th or 1/2 inch socket stub over which you fit with the appropriate socket head. You place this over the bolt and then use a hammer/mallet to hit the other end of the cylindrical tool while applying a slight twisting force on the body of the impact wrench. The perpendicular motion of the hammer is translated (via a system of springs and prawls) into a sudden twisting motion at the head of the troublesome bolt. Since static friction decreases so much when the force is applied over a very short duration —like the time it takes a hammer to smack the end of the impact wrench — bolts that would otherwise require so much force that they might snap off can be easily removed.
Regards,
egremont

trouble with that is acess to swing the hammer and b everything moving about

[SD1too]

Originally Posted by Mike Noc

I've got a few of theirs in the garage. All part of Facom now of course ...

Yes Mike; I have Britools from both the Facom and British eras. But I'm told that they're now under Stanley's USA ownership. My tools stamped "England" are those which I like the most.

Here's a nice story. I recently had to fit a new brake pressure reducing valve to my SD1. I considered that I needed a proper flared brake spanner to undo the unions without damage. On the internet I found a beautiful chrome plated Britool item with a part number so old that the computerised youngsters at HQ didn't know what I was talking about!

Originally Posted by marinabrian

No you're not the only one Simon, Dennis (as per avatar) is pictured standing against a 1/2 7/16 open ender ...

Marvellous! I couldn't be in better company then.

Simon

[andrewinpopayan]

I am going to make one of these, all the dealerships use them

https://www.youtube.com/watch?v=pVYMLnXW9uo

Get change out of a tenner

[HarryM1BYT]

Originally Posted by andrewinpopayan

I am going to make one of these, all the dealerships use them

https://www.youtube.com/watch?v=pVYMLnXW9uo

Get change out of a tenner

They can only heat things up, which can be got into the middle of the coil.

If you make one, do let us know how well it works. Interesting project, which will not cause the damage to other components, which a flame can cause.

[Jules]

We use an induction gun from USA.
I can confirm they work a trea!!.

Heat and cool with the coil several times before trying to loosen the offending bolt.
This helps break the 'rust bonding" or static friction between the threads.

The induction tool comes into its own for getting inner bearing races off stub axles without having to grind them off.

[sandman jim]

Originally Posted by HarryM1BYT

The next step up from heating, is cycling heat then cold. Heat a bolt up and it will expand in the hole or thread, cool it rapidly and it will shrink.

In a certain industry in which I was involved, where they dealt with some really rusted in bolts, they would use dry ice on bolts.

thanks harry..i have ordered a butane gas blow torch , should be here in a few days,,,,,when using heat do i apply to the bolt ? or the caliper mount where the bolt goes into,

[HarryM1BYT]

Originally Posted by sandman jim

thanks harry..i have ordered a butane gas blow torch , should be here in a few days,,,,,when using heat do i apply to the bolt ? or the caliper mount where the bolt goes into,

You don't want any heat, where there is anything which can be damaged by heat. That includes the hydraulic cylinders, the pipes, rubber suspension parts, or dampers.

Getting the female thread to expand, works best, but with the above reservations. Second best is heating the male thread, basically the bolt itself. It will expand in the female thread forcing itself some room inside.

What I have sometimes found works, is to get a bolt hot, than rapidly cool it with penetrating spray, but be wary of it catching fire - have water to hand just in case. The rapid cooling also tends to suck the penetrating spray along the threads as it cools. As Jules suggests, heat and cool several times, for best effect.

Had you mentioned buying a blow torch, I would have suggested that you might find a Benzomatic one a better bet. They are quite expensive, but they produce a very much smaller and hotter flame than the usual DIY type torch. They are supposed to be hot enough to melt brass/ braze, though I have never tried it. The gas tanks are also expensive, but they last a very, very long time. They are one of those lifetime investment tools.

You can help protect items from heat by wrapping them in wet rags.

[HarryM1BYT]

Originally Posted by Jules

We use an induction gun from USA.
I can confirm they work a trea!!.

Heat and cool with the coil several times before trying to loosen the offending bolt.
This helps break the 'rust bonding" or static friction between the threads.

The induction tool comes into its own for getting inner bearing races off stub axles without having to grind them off.

Interesting - any chance of a photo of this please?

[Dashiel]

Seem to remember they were 13mm. Use the right tool for the job. Better still chuck your imperial away as they are no use.

Get an extension on the bar.

[andrewinpopayan]

The idea is to get some heat onto the bolt/thread, over 150 degrees Loctite breaks down into a powder.
I did my 51 plate rear brakes last year and the bolts had never been removed, being left handed helped me get more force on the bolts, they were loctited from new.