The 75 and ZT Owners Club Forums - View Single Post - HELP. One of a handful of requests in 13.1/2 thousand posts.

COLVERT · 5th January 2022, 17:10

Baffled. The car failed its MOT today for the first time in 13 plus years.

Rear brakes well out of balance. One being OK the other showing only 64% braking effort.

The underside of the car is virtually rust free.--Nothing on or around the caliper.

Stripped the caliper down and no corrosion under the piston seal.
It's possible to slide the piston in and out about 3/8 " without too much effort.

I expected to find a partially seized piston.
No such luck.--

Now the question for those DIY experts on here. Is it possible to have air in that single line to the LH rear caliper to give that result on the MOT ??

Could the anti-lock braking system be involved here somewhere ??

The reservoir has lost no fluid. No sign of a leak anywhere. If air is getting in then maybe a small stain from leaking fluid should be apparent.--

I have pics of all the bits on my smart phone but have no idea how to post them on the forum.

Year after year life is getting more and more complicated when all I want to do is sink gently into old age and oblivion.

However I seem to have ended up with this red hot needle where I don't want it.

5th January 2022, 17:10	#1
COLVERT This is my second home R75 Saloon. Join Date: Feb 2009 Location: France/or Devon. Posts: 14,003 Thanks: 3,851 Thanked 2,167 Times in 1,816 Posts	HELP. One of a handful of requests in 13.1/2 thousand posts. Baffled. The car failed its MOT today for the first time in 13 plus years. Rear brakes well out of balance. One being OK the other showing only 64% braking effort. The underside of the car is virtually rust free.--Nothing on or around the caliper. Stripped the caliper down and no corrosion under the piston seal. It's possible to slide the piston in and out about 3/8 " without too much effort. I expected to find a partially seized piston. No such luck.-- Now the question for those DIY experts on here. Is it possible to have air in that single line to the LH rear caliper to give that result on the MOT ?? Could the anti-lock braking system be involved here somewhere ?? The reservoir has lost no fluid. No sign of a leak anywhere. If air is getting in then maybe a small stain from leaking fluid should be apparent.-- I have pics of all the bits on my smart phone but have no idea how to post them on the forum. Year after year life is getting more and more complicated when all I want to do is sink gently into old age and oblivion. However I seem to have ended up with this red hot needle where I don't want it.