Xfr 2010

​​​​Hi I'm having a soft spongy break pedal, there are no fluid leaks. I just had rotors and pads changed in all wheels, bleeding was apparently done.

I suspect master cylinder seals are worn.
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With car shut off pumping the pedal hardens it, when turning it on is gets spongy has free play about an inch before I get some resistance, i tried pumping it a few times when car idling and then pressing it down hard all the way, it gets resistance but keeps depressing slowly all the way down.
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any suggestions on other testings i can do to point out the culprit?

 

What I would do is put a line clamp on the four brake hoses. The pedal should be rock hard. If it is not, the problem is in the master. If it is hard, remove one clamp and test the pedal. Put the clamp back and remove another one and test.again. Repeat for the other two. If the problem is in a caliper, the pedal will be soft when the clamp is removed.

 

On a previous vehicle I had, a shop didn’t do the brake fluid flush properly and I had a spongy pedal. After a friend and I did it ourselves it was solid again. I don’t know if that is what’s happening with yours but something to look into.

 

Maybe I'm not sure I just had a complete brake job done new pads and rotors, i also asked them to change the fluid, maybe the bleeding wasn't done in the correct order, I'll check that before blaming the master cylinder.
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I would bleed them again.
I would not clamp the brake lines as most modern Jaguars have SS braided brake line which are very nice/expensive and you don't want to damage them.
They are plastic covered so they might look like the old rubber hoses but my old 2005 STR and my newer 29014 XJR both have SS lines from the factory.
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I'm on it right now, when you did it with your friend did you get many air bubbles out?, I've gotten very little maybe 3 or 4 bubbles, don't know if that little will affect .
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Didn't make any difference, calipers checked no leaks.

On the other had this is the first time I own a jaguar xfr 2010, how should the brakes feel, please anyone with a. Xfr?, according to the manual it's normal for them to be soft, i compare it to other cars i owned and this just doesn't feel right. I got new rotors drilled and slotted + Brembo ceramic pads.

I strongly believe it's the master cylinder.

 

If you did all four calipers and only had a few bubbles then maybe it is the master cylinder. Just out of curiosity, how did you do your brake flush?
my brakes on the xfr are not spongy and are comfortably stiff.

 

I'm not sure I wasn't at the shop when the changed the fluid, but i was there yesterday checking the bleeding, we did it in the order the manual says, is there any special procedure for flushing?

 

I was just wondering if you did it yourself. When my buddy helped me do mine, he started on the line that was the furthest from the master cylinder first, then finished with the one that’s closest. I’ve been told that’s the old school method and it’s not needed on modern systems.

 

Yep that's what we did at the shop started back from passengers sides , just as the manual states, so I guess its the master cylinder, apparently there are no rebuild kits with the orings, gotta buy the whole thing.

 

I did think of one thing that might be involved?
When I changed to ceramic Akebono pads on my old STR I thought the pedal felt a bit mushy. I bled and bled the brakes with no change. They stopped fine it was just the feel was not as good as I like it.

Found out from further reading that ceramic pads tend to give a softer pedal feel compared to others especially when compared to the factory Brembo pads the STR came with. Which had a very quick and positive initial bite when braking. Almost a bit too much for smooth street driving.

Maybe just the difference in pads is what your feeling?
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Yes I'm aware of that, the thing is that before I did the brake job, i had the OEM metallic pads and the pedal felt the same. I felt no difference at all after the brake job.

 

would the type/brand of brake fluid used cause a change?

 

99% it's the master cylinder.

 

Used
Dot 4 / Mannol.

No change exactly as it was before the brake job...

 

I strongly believe the same thing.
I just wanted to get more advice on what other testing to do, to be 100% sure before I buy a new one.

Servo works, with the car off pumping the pedal gets hard, turn on it sinks smoothly, so I can rule the booster out.

 

I have read that it might need abs bleeding with scan tool or ssd, don't know if that's the case, manual says nothing about that. I have also read that some guys have done it the old fashioned way, without any scan tool maybe this applies for newer cars.

 

I've changed the brake fluid on my 2002 STR, a 2004 S-type TDV6 & 2009 XFS, along with changing some calipers on all of them. Always bled using 'regular' technique & never had a problem. Just once I had some air trapped somewhere, so took it for a slow drive over a bumpy road for a while, then re-bled & a little more air came out which fixed it.

 

One thing I don't think you've said. How's it stopping ? Are the brakes working OK & you've just got a spongey feel at the pedal ?

 

My 2011 called for DOT, low viscosity. Don't know if Mannol is LV or not, or if it would make difference.