Hi Everyone,

Yet again I am stumped. I replaced the front and rear shocks and springs in my XKR and had a front brake line rupture. Replaced the brake line with a very nice Centric line recommended by fmertz. There are no leaks anywhere that I can see and I have bled the brakes 4 times now but am still getting a soft pedal the first time I press the pedal down. It goes almost to the floor. If I let the pedal up and the press it again they get firmer and by the third pump they are perfect. I thought I had air in the line hence the numerous attempts at bleeding both using the Jaguar recommended sequence of front left, front right, back left, and back right and also the traditional sequence of the furthest line first and working your way up to the front left.

At this point, I have run a little over a liter of Dot 4 fluid through and there are no signs of bubbles and the fluid coming out is very fresh and clean. Also, at this point, my wife is getting verrrrry tired of coming out of the house to pump the brakes for me! I was wondering if anyone had any thoughts on what this could be aside from air in the line. No leaks anywhere that I can find and the brakes work perfectly after three pumps. Might try one more bleed tonight and if that doesn't work then it might be time to take it in to the shop.

Thanks!

Corey

 

Have you checked the master cylinder?

 

It was working perfectly before I had the brake line go out. Maybe it somehow went bad during the day that the line was leaking and when I replaced the line. The brake fluid low light did come on but I visually confirmed that the reservoir never emptied.

Just curious, how would you actually check the master cylinder? Thanks!

 

You already know this, each Brembo caliper has 2 bleeders. Each side has to be bled separately.

Sometimes gently hitting the caliper with a plastic/rubber hammer helps dislodge additional air bubbles.

If you have the required apparatus, you can try pressure bleeding. Maybe the additional flow generated by the air pressure on the reservoir can somehow dislodge trapped bubbles.

Next time it rains (or if there is a slippery surface around), maybe try and brake hard enough to activate the ABS. See if that helps, or if any subsequent bleed releases more air.

There is a mystery procedure people sometimes talk about. There seem to be circumstances where air is introduced into the system and somehow gets trapped into the master cylinder. The remedy is to perform "bench bleeding". I am unsure of the details, you might have to look it up. People sometimes complain that their Brembo setup should not have that spongy feel on initial application of pedal pressure. This bench bleeding procedure has been reported before as a solid remedy.

Best of luck, keep us posted.

 

I am embarrassed to say that I did not already know that! Wow, thank you for sharing that information. It makes sense and most likely this is the problem. I was reading many posts about bench bleeding the master and was thinking that might be the next step. Never done it before but figured it would be yet another learning experience. That is what is so much fun for me about these cars. You learn so much about mechanics and how cars work and just keep building the knowledge base, and tool inventory, over the years. Sure is a fun hobby and we are saving serious $$$ along the way as well which is a plus.

Seems like it is most likely the second set of bleed screws which will fix my problem. Going to do this as soon as I get home from work today and share the results. I think I have one more bleed sequence left in my wife so I am praying that it works this time :-)

 

Hopefully someone will explain to me the difference between the jag xkr set up and,,,, well, everything else ive ever worked on... in my experience (although limited) i was always told to bleed the brake furthest from the master,,, and work to closest when bleeding. So, the farthest rear, closest rear, furthest front, closet front. Is the xkr different?

 

The technique for Brembo is:

Prepare the Left Front caliper for bleeding.
1. Apply pressure to brake pedal.
2. Open caliper's outer bleed nipple.
3. Fully depress brake pedal.
4. Close bleed nipple.
5. Release brake pedal.
6. Wait two seconds to allow system to prime.
7. Repeat procedure until air-free brake fluid is expelled from the bleed nipple.
8. Repeat procedure to caliper's inner bleed nipple.

The recommended Jaguar sequence is:
1. Left - Front
2. Right - Front
3. Left - Rear
4. Right - Rear

However, having tried shortest line first and the opposite of longest line first, I've found it makes absolutely no difference where you start.

Graham

 

Thanks Graham...!

 

Hi Everyone,

I just wanted to provide an update. The brakes are 100% now! Thanks to the suggestions and reminder that the Brembo's have two bleed nipples on each caliper the pedal is as firm as can be. The silver lining in all of this is that the brakes are now the best they have ever been, even better than before I had the brake line issue since I had been bleeding only the front nipple for years.

Thank you to everyone for being so generous with their knowledge and time!

Best,

Corey

 

$0 fix FTW

 

NICE!
Thanks to Mertz!

 

Thanks for posting the successful resolution. I bet the "pedal pusher" was delighted.

I've added RESOLVED to your thread title.

Graham

 

S-W-E-E-T !!! I like better than ever. It's my fave! TM

 

What a great fix and a nice improvement to the pedal feel. Can you get to the inner bleed nipples with the wheels on the car, or do they have to come off to get access?

 

That is a great question. I took the wheels off since I was doing some other work that had them off. It was very easy with them off and I think a lot depends on your wheels. I have the Montreals which afford ample access to the front nipples and I would suspect that I could get to the backs with the wheels on but I would not risk it. The reasons for that would be not wanting to risk rounding the bleed nipple by working on it from an awkward angle and also I think it might be more difficult to ensure the brake fluid does not get on the caliper or wheels.