Avensis Caliper Replacement

[astoy]

Hi,

A mobile mechanic replaced a solid brake line for me, but in doing so sheared off the bleed nipple on the rear right caliper.

As he wanted £180 to replace the caliper (said the nipple was ceased up) I bought one and replaced it myself.

This is the first time I've replaced a caliper though, and I can't get the thing moving.

It came with generic instructions "Turn clockwise then back anticlockwise half a turn" / "connect brake cable(?!?!?!?)" which didn't seem relevent to the Toyota d4D avensis design.

I've bled it, fitted it, but can't get it moving.

I can't see any pins, or release screws etc that might have needed removing before fitting.

Does anyone have any pointers that will help me, or is this a duff unit?

 

Thanks,

 

-Andy

[Konrad C]

I have not replaced a caliper but have done brake pad replacements on quite a few cars recently - My Toyota Avensis, Renault Grand Scenic and Vauxhall Corsa VXR.

I use this tool kit to wind back the pistons - 

 When doing the Corsa, I made the mistake of using the right hand side on the left, jamming the whole lot! Lucky I used a technique of turning the tool,whilst applying pressure against the piston. Once I could remove the tool, I used the correct left hand tool to complete the job. The secret is forcing the piston in whilst turning it the correct way. 
Generally it needs a bit of force to turn the pistons, even using the correct tools. 

A little caution when replacing rear brake pads on some cars. The pistons have cutouts used to engage the tools to turn in. Make sure the cutouts are horizontal to the caliper, because the there may be pins on the back of the pads. The pins need to sit in the cutouts, or they will damage the pistons and cause the brake pads to wear at an angle, which in turn damage the discs if not caught in time! This also aids putting the caliper in place.  

Edited April 11, 2019 by Konrad C
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[astoy]

Hi Konradcy,

 

That's a fancy kit, I've only ever used a large screwdriver and a G-Clamp(! ) - I'll probably be told off for saying that now! - when replacing the brake pads.
 

This problem is more the reverse of that - the cylinder is backed all the way back into the cylinder housing of the calipers. It's a new cylinder from the supplier, so hasn't had any brake fluid into it until I bled the brakes yesterday.

I'm starting to think maybe the fluid path into the cylinder main face is so close to the housing that it's not seeing the hydraulic fluid or pressure.

Does that sound feasible?

Cheers,

 

-Andy

[Konrad C]

If you have put everything back together, pull the handbrake and press the brakes. One or the other will adjust the piston and pads to the discs. I would give that a try. 

[alan333]

Verify that fluid is getting to the caliper when the brake is pressed - I once had to bleed a car (maybe a Peugeot 505, can't remember) with the engine running.

[astoy]

I've jacked up the other side and bled there. 

Seems to be fluid all through. 

Brakes also worked fine on that side.

I'll fire up the engine again and watch the fluid levels. 

See how the brakes feel on the gentle slope then jack up and retry the wheel again. 

It may be a case of re bleeding with the engine running.