MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: Jigwar on April 18, 2010, 21:38

Title: (Rear) Caliper - How Does Handbrake Work?
Post by: Jigwar on April 18, 2010, 21:38
Can someone explain the workings inside a rear caliper when the lever (on the caliper itself) is pulled by the handbrake cable supposedly to engage the handbrake?

Story is that having noticed the handbrake not holding the car, I checked over all the relevant bits today:

 - Works fine on passenger side wheel, not at all on drivers side
 - Cable moving fine on drivers side though
 - Lever on caliper moving on drivers side, to its full extent
 - I then pushed the caliper lever back to its starting position manually, adjusted the cable (as per instructions on here), still no joy
 - Disconnected the cable from the caliper and operated the lever manually, still nothing
 - Footbrake works fine on this caliper
 - Handbrake mechanism in this caliper simply doesn't move the piston at all.

Hence to me being stumped and the above question being asked!

Any help gratefully received.

Steve
Title: Re: (Rear) Caliper - How Does Handbrake Work?
Post by: muffdan on April 18, 2010, 21:45
That sucks Steve.

There's a ratchet inside. Sounds like something is broken and it needs a rebuild and repair or you need new one. I'd go for a new one if I were you  s:) :) s:)
Title: Re: (Rear) Caliper - How Does Handbrake Work?
Post by: custardavenger on April 18, 2010, 22:23
OK here goes

The lever operates a small rod which in turn moves a rod inside the piston which has a helix thread on it. Works with a loose nut which is attached to the piston and form the auto adjust mechanism.

I would guess that the adjuster isn't turning on that side. I'm afraid I didn't take many pictures when I rebuilt mine as I was in a hurry. If you need a hand fixing it or need to borrow the kit to do it let me know.
Title: Re: (Rear) Caliper - How Does Handbrake Work?
Post by: markiii on April 18, 2010, 22:25
Steve

Jaik has my spare set of calipers, if hes finished swapping them over and the caliper your after is serviceable feel free to swap, as they will only be going back to big red when the next person wants a refurb
Title: Re: (Rear) Caliper - How Does Handbrake Work?
Post by: Jigwar on April 19, 2010, 12:05
Thanks guys.

Not sure this is something I'd take on myself, think I reached my limit with getting the caliper off and handbrake cable disconnected!

Have PM'ed Jaik for the spares.

Steve
Title: Re: (Rear) Caliper - How Does Handbrake Work?
Post by: Jigwar on April 20, 2010, 14:04
No reply from Jaik, so does anyone have a spare rear driver's side caliper they can lend me for Thursday for about a week?

Bit of an emergency as MOT is due on Thurs and this puts my attendance at the Southern Softies run in jeopardy on Sunday   s:( :( s:(

Will source a long term replacement during this week so as mentioned would only be a loan.

Thanks,

Steve