Front Brake Calliper pistons

[Jim H]

At the moment, I'm changing my front discs and pads. however this afternoon I can't seam to push the piston back on either calliper. I've tried what I usually do with other cars, using a crow bar and old pads to leaver it, but the piston doesn't want to budge.

 

What have you found the best technique of pushing them back?

[fletch101]

Water pump plyers if its off orrr with the caliper bolted on. A good flat head screw driver

[Jim H]

I tried water pump pliers, but couldn't quite get the reach. I might try a screwdriver levering on the disc, but a long crow bar hasn't worked. I've even been out and bought a calliper rewind tool, but that didn't seam to work either.

 

Will you need to open the bleed nipple, although I'm sure I haven't in the past.

 

 

[fletch101]

Sounds like its sized . But I cant see noth seizing.

You must just be out of practice. No you dont have to open nipples.

[coskev]

Take the cap off resevoir or open bleed nipples will make it much easier

[TeflonTom]

It's probably because the reservoir is full and with the cap on there's nowhere for it to go.

[coskev]

Also put your old pads back in, then lever between pad and disc.

Spreads the load evenly over piston rather than just one side which can cause them to go in on a angle and get tight in the bore

[Jim H]

Seized (or stiff) pistons is what I'm fearing, especially after 10 years and 97k miles. I also noticed the inner pads have worn more than outer ones, but sliders seam fine.

 

I've changed pads and discs before on this car, I just wish I took pic of how I did it the last time.   I might try and find a G-clamp as I'm sure I've got one somewhere. (not actually used it) The good thing is I've got the week off work to try and sort it.

[TMB]

I always use a G clamp.

[coskev]

You will get different wear from inner to outer pad, as the inner pad will allways be used more.

Front calipers rarely seize, unless the dust cover is split, or the car has stood for a long time.

 

FYI the caliper rewind tool is made for calipers that need both pushing and turning at the same time to get piston back in,ie rear calipers with a handbrake mech built into caliper.

[hutchysrs50]

Strip one side at a time, with the caliper off the disc press the brake pedal to push the piston out slightly (not to far) use a small screw driver to pull the boot open and put some brake fluid in between the boot and the piston.

Then try pushing it back, should be much easier.

As also said, I open the bleed nipples on the difficult ones, usually helps.

[Jim H]

You will get different wear from inner to outer pad, as the inner pad will allways be used more.

Front calipers rarely seize, unless the dust cover is split, or the car has stood for a long time.

 

FYI the caliper rewind tool is made for calipers that need both pushing and turning at the same time to get piston back in,ie rear calipers with a handbrake mech built into caliper.

 

Thanks for that boost in confidence. The rubber on initial looking looks old, dry, but intact. I shall have a closer inspection of them. I use the car every day, so they certainly haven't been stood around. I'm just hoping it's simply the technique I'm using that's wrong and not the caliper that's at fault.

[TeflonTom]

Did you check that the fluid reservoir is not overflowing?

[Jim H]

Can't be overflowing as Pistons are out and I've never needed to top up the reservoir, unless it was done on a service early last year by the garage, which I don't think it was. I'll check it though.

 

The fluid probably wants changing as last time I asked for it to be done, the mechanic said he was too scared in snapping the bleed nipples off.

[Eccentric Toast]

I also recommend a G clamp with an old pad. Make sure it's sliding back in perfectly straight though.

Sent from my GT-I9505 using Tapatalk

[Jim H]

Problem Solved.

 

I was on the brink of removing callipers and sending them off to be refurbished. I tried to move the piston with the brake pedal, but it didn't budge. I didn't need to, they could do with a coat of paint though.

 

What I was doing is trying to push the piston back with the calliper up in the air. This was bending and kinking the brake hose. All I needed to do is lower it and the piston moved in nice and smoothly.

 

So I was right all along. it was the wrong technique I was using and nothing wrong with the callipers.

[coskev]

 

 

Glad its sorted!!

[Jim H]

Is this pad wear normal?

 

NSF

 

 

OSF (with cleaner hands, lol)

 

 

above was, outer pad had 5.5/6mm pad left, inner, had 0mm. (new pads have approx 12mm)

 

NS Disc

 

 

 

Not keen on the inner surface of it.

 

 

This is the thread when I fitted them. http://www.briskoda.net/forums/topic/220967-i-think-ill-stop-now/   They were fitted at 74k miles, car has now done, 97k miles

 

Any comments?

[TMB]

That's the worst brake disc I've ever seen.

[TeflonTom]

its not uncommon for inner outer pads to wear at different rates especially if they have different surface areas.. those discs are not pretty but they will go again with a clean up, I've seen much worse

[coskev]

Jesus,what sort of noises were you getting from them!!!

[TMB]

Jesus,what sort of noises were you getting from them!!!

 

That's what I was thinking. That disc is utterly trashed.

[coskev]

It looks to me that the brakes are not used heavily,so the discs are not getting 'cleaned' up by the pads.

[TMB]

It looks to me that the brakes are not used heavily,so the discs are not getting 'cleaned' up by the pads.

 

Yeah, either that or the brakes are not working properly because something is seized.