Help...I cant get the front brake caliper off...any ideas.

[Sprackers]

I have read all the threads and manuals already.

I have taken off the wheel, removed the two big nuts on the inside of the caliper.

I have removed the two split pins and also the two shoes at the top and bottom of the caliper.

And according to all the manuals and threads, the caliper should come off.

Mine doesnt.

I am able to turn the whheel drum with my left hand whilst holding the calper in my right hand and the wheel (brake drum) turns.

I have checked the hand brake. Off. and there is no one in the car putting on the foot brake.

What can I do?

 

[Sprackers]

I had a long look and its as if the brake is still on very slightly.

I wiggled and pulled and wiggled and pulled and eventually after 30 moins the caliper has come off.

Now has anyone any idea, it seems as if the piston is not retuning fully back.

Has anyone had this problem before?

 

[petak]

Did you tried to force piston inside, with clamp?

If still does not want to go then there is chance that pistons have rusted inside and would not get back whole way.
In that case you can try to sand it/polish it with fine sand paper...
But would recommend renew calipers (new pistons, new rubbers, and new vent)

 

[Sprackers]

Hi Petak

Didnt have a clamp but tried to push the piston back in hard with the use of a drift and a screwdriver. Put a lot of force and it didnt budge in at all.

Haynes says to use a a flat head screwdriver and expect a bit of brake fluid to come out of the reservoir as you push it in.

Well nothing so I think you could be right. IT looked a bit rusty when I took it off but that could just be from the brake pads.

ITs difficult to know what should move and what shouldnt.

Thanks for your help.

 

[petak]

You can try to remove grommet around piston to see state of piston inside caliper. That is just dust grommet and no oil will get out.
It is hold down to caliper with o-ring metal spring

 

[Sprackers]

Brilliant. I was tempted to take off that rubber cover but wastnt sure if I should touch it.

Will take it off and see if I can losen up the piston with some WD40.

 

[malcolm]

The pistons only withdraw a tiny amount when you take your foot off the brake pedal.

If the brake discs are in poor conditon it can be a pain to remove the calliper. Needs a screw driver to push the brake pads out.

If you are fitting new pads and discs then press the pistons back into the calliper using a G clamp before re-fitting the callipers. I wouldn't disturb the dust seals.

 

[Sprackers]

OK wont touch the dust cover. Let sleeping dogs lie an all. I will be taking off the otherside so I can compare. The car does stop well.

 

[retrospecparts]

I have known (on other cars) apparently seized calipers to be caused by a blockage in either the brake pipe or flexible hose.
There may be sufficient pressure, when braking, for fluid to pass through a blockage but not for it to return, even with a g-clamp. If after loosening or removing either the bleed screw or the brake hose at (the caliper end), the piston then moves back more easily, then you have a blockage:
Check along the metal pipe to see if it has been squashed/crushed by anything. If not it is probably that the flexible hose has collapsed internally.

 

[Sprackers]

Brillant thanks. I will do some more investigation.

 

[Sprackers]

Conclusion:

I did manage to move the brake piston in using a flat head screwdriver .

I got the brake caliper off

Once off I had a look at the piston and the dust cover.

I very very carfully removed the dust cover.
I then pumped the brake pedal very very slowely and the piston came out.

I pushed the piston out to about an inch.

The inch that came out was a bit gunky and not so much rust but half way between rust and gunk

I then cleaned the outside of the piston with a very fine sand paper for metal. Didnt need much sanding about a minute.
It was nice and shiny and clean.
I sprayed WD40 around the outside of the piston.
Carfully replace the dust cover
Replaced the Caliper.

My thinking is it has to help the piston retract when I take my foot off the brake. It could do no harm.

Went for a test drive and the brake woked fine and I felt happy that I had done everything possible to help it return.