Tech advise on seized caliper

[rob18362]

The front pin that the rear caliper slides on has seized and is preventing me fitting new pads. Have tried WD40 and a small hammer to no avail. Don't want to use the blow lamp as it will damage the paint.
Can any one offer advise?
No not a bigger hammer!!
Cheers.

 

[Possu]

I have a similar problem that I'll be dealing with this weekend.

I'll remove the calipers & put them in a vice after draining the fluid.

I'll try heating the caliper body around the pin area with hot water to expand the body before trying to drift the pin out.

If that fails, I'll heat it up with a hot air gun, which worked well when I heated up the bevel box recently to replace the Paralever bearings.

I've just bought stainless pins from MotoBins - no point in putting the same prone to corrosion steel pins back in. I used to run Suzukis for years & never had this problem, even on bikes that lived outside?

 

[sproggy]

I used to run Suzukis for years & never had this problem, even on bikes that lived outside?

I think the problem is that the little rubber bellows don't grip tight enough - they either fall off at one end or just allow moisture to seep in through not being tight enough.

This isn't mentioned in the service schedule but I pull the bellows back, put in plenty of copper grease, and then re-seat at each service. Not much help when they're already siezed, I realise, but good preventative medicine.

Another possibility (which I haven't tried) would be to use something like lock-wire to bind the ends onto their mountings a bit tighter.

 

[Possu]

I think the problem is that the little rubber bellows don't grip tight enough - they either fall off at one end or just allow moisture to seep in through not being tight enough.

This isn't mentioned in the service schedule but I pull the bellows back, put in plenty of copper grease, and then re-seat at each service. Not much help when they're already siezed, I realise, but good preventative medicine.

Another possibility (which I haven't tried) would be to use something like lock-wire to bind the ends onto their mountings a bit tighter.

I believe you've misunderstood what we're talking about.

I'm referring to the steel pins that locate the pads in place, not the rubber seals around the caliper pistons.

 

[Taipan]

The front pin that the rear caliper slides on has seized and is preventing me fitting new pads. Have tried WD40 and a small hammer to no avail. Don't want to use the blow lamp as it will damage the paint.
Can any one offer advise?
No not a bigger hammer!!
Cheers.

I know you say no, not a bigger hammer, but it is normally "impact engineering" that does it.
Get a drift that has the same size or smaller diameter of the pin. A large heavy hammer. One extension lead and one kettle of hot water.
Boil kettle next to bike. When kettle clicks off, pour boiling water over the caliper where the pin is inside, trying if possible to eek a much water away from the pin as possible. Once kettle is emptied. The alloy should have expanded quicker than the steel. So place drift against pin and whack sharply. It should shift. Mine did.
You wouldn’t believe how hard mechanics whack things behind closed workshop doors!

 

[Steptoe]

The front pin that the rear caliper slides on has seized and is preventing me fitting new pads.

Your causing a bit of confusion -

do you mean the pin that the caliper slides on -

or the pin that retains the brake pads -

?????????????/

 

[sproggy]

I believe you've misunderstood what we're talking about.

Well "The front pin that the rear caliper slides on" was what I thought this thread was about.

I'm referring to the steel pins that locate the pads in place, not the rubber seals around the caliper pistons.

The steel pins that locate the pads are not the pins that the rear calliper slides on. And neither relate to the rubber seals around the calliper pistons which I didn't even mention!

There's certainly some misunderstanding here but I don't think it's me....

 

[rob18362]

Sproggy is right!

Sorry for those that have been confused by the fact that I mentioned pad replacement but Spoggy is talking about the right pin which is why I had said it was the pin the caliper slides on. Had thought that would make it clear.
Left WD40 on it overnight and went for the next hammer up but still no joy.
May have to remove it and get it in the vice as suggected unless anyone can suggest any other tips.
Thanks for all the interest, Rob.