Had new rear brake caliper fitted, odd brake feelings now?

mikesndbs

Active Member
Apr 3, 2010
588
3
West Sussex UK
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Hi guys, happy new year to you.

Still with the Leon, always get her worked on at JKM.

However the other day I had to go local as my NSR wheel almost jammed up, I am 30 miles from JKM so could not get there.

Local place seemed very good.

New caliper fitted, new discs and pads at the rear.

However driving home brake pedal felt spongy but the garage told me this was only while the new pads and discs bedded in 100 miles time.

However I was waiting at a busy roundabout today and had my foot on the brake, I noticed that it was slowly sinking all the way down to the floor, well almost, by no means moving quickly but was on its way and I found this to be a very unnerving feeling and not one I know.

Went back to the garage and they rebled the system, and while the brakes feel a bit better the sinking pedal still happens.

Now I know there is a specific procedure for bleeding these systems and discussed this with the garage owner, he seemed fully aware of it.

Loads of driving to do next week and worried, can anyone suggest what might be going on, have they shagged my master cylinder? Bloody hope not :(
 
Last edited:

bruceR

Active Member
Apr 11, 2005
2,540
616
Monifieth, Dundee
If they used the pedal pumping method then it probably the case they’ve rolled the seal in master cylinder - but doesn’t always happen.
The brakes should be pressure bled.


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mikesndbs

Active Member
Apr 3, 2010
588
3
West Sussex UK
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I wonder if I am just panicking after the initial spongy feeling, since the rebled that's better.
I am not saying I am chasing the pedal down, far from it, I have to press it down and it slowly descends, is this just normal movement as I am increasing the demand for brake pressure?
I took the car out and parked up on some steep slopes, used the brake to just hold the car and then locked my foot, at no time did the brake fail and in fact when I slipped first gear in she stalled against the break?
Thoughts
 

Legojon

I only wanted a remap
Staff member
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Jul 7, 2015
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If there's travel in the pedal sounds like there's air in the system. This makes the pedal spongy because you have to compress the air in the lines before you can apply the brakes. So at first it's a bit like a bellows. Then you get onto the braking.

But yes, pads and discs have to be worn in. I've just done the fronts myself and the first 50 miles were horrible. But they are just starting to bite now. Even the box has a warning of not trying to brake hard till they are bedded.

I know it's more money you shouldn't have to spend. But maybe as above, take it to your usual place for pressure bleeding.

Just to add. Most of the braking is done at the front. So I've noticed a big difference. I wouldn't have thought bedding the rears would have made that much of a difference to feel.
 

Sparkie

Angling Adict.
Sep 25, 2009
2,541
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Middlesex
I don’t know what Leon you have but with my R it’s a pain in the ....
My mechanic buddy has to do them several times each time I have new fluid or callipers etc.
Uses a pressure bleeder too.
Should be perfect first time but usually spongy and have to return over and over.
Last time changed a rear calliper and we bled them 3 times until it was firm again.
You may not get best braking with new pads and discs for a few miles but it should feel firm on the pedal. Not spongy.
If it feels wrong it probably still is wrong.
Did discs and calliper change a year back and that took 3 bleeds too.
Plenty of people have the same issue with the mk1 R brakes .
Apparently you can purge the ABS using vcds and this can make a difference too.



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RADIOTWO

Active Member
Mar 6, 2018
488
94
North Derbyshire
I don’t know what Leon you have but with my R it’s a pain in the ....
My mechanic buddy has to do them several times each time I have new fluid or callipers etc.
Uses a pressure bleeder too.
Should be perfect first time but usually spongy and have to return over and over.
Last time changed a rear calliper and we bled them 3 times until it was firm again.
You may not get best braking with new pads and discs for a few miles but it should feel firm on the pedal. Not spongy.
If it feels wrong it probably still is wrong.
Did discs and calliper change a year back and that took 3 bleeds too.
Plenty of people have the same issue with the mk1 R brakes .
Apparently you can purge the ABS using vcds and this can make a difference too.



Badger5 Custom Map + TIP,
3” Sustem, FMIC, Bosh 550’s,
BC Coilovers, ARB’s +loads more.
Hi
"Did discs and calliper change a year back and that took 3 bleeds too. "
Why did you need to bleed the brakes after a disc/Pad change ?
 

Yellow fr

Gone to new owner so seat less for now
Sep 6, 2018
1,547
1,062
Sandbeds West Yorkshire
You may have to remove the new rear calliper as if you are putting a new set off pads in then get a bottle with a tube that goes onto your bleed nipple on that calliper make sure they is some brake fluid in the bottle and the end off the pipe is in the fluid open the bleed nipple and wind the piston back and see if you get any air out it helps if you use a clear pipe you may need to close the bleed nipple and pump the brake pedal till the piston comes back out a bit then repeat till no air is coming out

New callipers are a pain as they hold air in them sometimes
Just had to do this on a yeti that we fit a pair off new callipers too
Handy garage tip


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