I have a 2016 Jaguar xjl 5.0l. The brake is going down quite a ways before it seemed like the brakes started grabbing. Had a brake job done with factory pads and had the rotors replaced ( Not factory). Both front and back. The pedal is still going down quite a ways before there is any braking. Is this normal for this Jag? Or do I need to look further? Any advice would be welcome. Had a local shop perform the brake job as I would have to drive to Dallas to get it done. That is about 400 miles, but might end up having to do that. Thanks

 

Have the brake lines checked for leaks, have the brake fluid bled to remove air and make sure the brake fluid is properly filled.. If this doesn't fix the problem, you have bigger issues.

 

Just had a complete brake job done last week at a shop in Orange County that only serves Land Rover & Jaguar. Brakes were fine but the "pad low" light was on, so changed all rotors, pads and sensors. After finished the work, car was undriveable., Shop owner wouldn't let me drive it off the lot cause pedal was going too far down. Said that the brake job does not open the brake lines, and thus no air could have gotten in the the lines, and so it must be a bad master cylinder (even though car felt fine driving into shop). Not trusting his advise to leave car for 4 more days to order and replace cylinder, had car towed back to my local dealership. Diagnosis revealed (you guessed it) air in the brake line. Bleed the lines and car works perfect.
So I suggest they check the lines for possible air.

 

jaybird, I can think of 2 things that can lead to what you are seeing. The first being air in the lines. That is the most likely. Besides, I know when I have done my brakes on this car, you could not push the rear pistons in without opening the port. I am sure with enough force you could. But then, I would be suspecting damage to the ABS unit. Besides, this is the easiest of things to check and correct. The second thing could be that they did not adjust the rear calipers correctly when they put on the new pads and what you are feeling is one (or both) of the rear calipers is having to travel a little further than it needs to to allow the pad to press against the rotor. In this case, I would say to start the car, leave it in park and simply engage and disengage the e-brake like 15 times. Engaging and disengaging the e-brake will adjust the rear caliper (assuming there is nothing wrong with the caliper) to the proper position. Granted, if this was the case, I would think that you would have gotten an error message saying that the e-brake system requires adjustment as the computer would have seen the cable being pulled too far.

Checking the lines for a leak is a good check too. This can be done as easily as having the car sitting somewhere, pump the brakes 10 times and then looking inside the rims for any fluid and then looking under the car for any puddles. If you can get the peddle to get hard, you should feel it go to a position and stay there. If your foot slowly continues to drop, then you have a leak.

 

Thanks guys. I appreciate the feed back. Will try the emergency brake resetting. Im already set up for them to check the lines. They said they never opened the system which is probably true. But I did have the calipers painted and they took them off the car. That might have caused the problem May have a complete flush of the lines and go from there. Thanks again. But I'm enjoying this big car. The ride is just great, and still get almost 27 mpg on the highway. Again thanks, Jaybird!

 

If they took the calipers off, they opened the system and allowed air into the lines. I would bet that bleeding the brake system will fix the problem.

 

My mechanic also said they never opened the line, yet somehow air got in during the brake job.

 

Thermo: Well i gave it a try and reset the rear brakes using the e-brake and it appeared to have helped. I don't have to press down as far on the brake peddle to start getting brake. I did notice that every time I set the brakes i noticed the brake peddle falling. maybe it is wishful thinking but the more I did the reset the less it seems to have fallen. Ill give this a try for a little while and use the e-brake more often. Jaybird

 

jaybird, you will feel the pedal drop slightly every time you engage the e-brake is because you are actuating the brakes and the piston moves slightly. This will result in the brake pedal moving slightly.

From the sounds of things, you may need to do the e-brake application a bit more. The other way is to remove the rear wheels and using your thumb (or a screw driver) to actuate the e-brake lever. This way you can see the gap between the pad and the rotor. The gap should be very minimal. You will also notice that when there is a larger gap, you can move the lever the full distance. When the pad gets close, you will only be able to move the lever a little bit.

 

Thermo, Yes sir this happening as you describe. So my plan from here on out is to used the e-brake all the time and maybe stay ahead of the game. They are feeling pretty good right now. Not optimum but allot better than before i started this procedure. Also the shop that I used had to order the brake pads from the dealership in Dallas and the rear brake pads had to come out of Atlanta. Is every one using OEM brake pads or is there an aftermarket that people think are better? jaybird

 

jaybird, to help speed things along, when you go to park your car, find a flat spot. From there, put the car in Park and let your foot off of the brake. At this point, now engage the e-brake. What this does is maximize the distance the e-brake has to move the lever to get the e-brake to engage. This will cause the piston to be ratcheted into place faster.

As for pads, I have only bought and installed 1 set on my car. Don't recall the name on the pads. I just remember that it was a major manufacturer. I have a new set of pads and rotors sitting at my house that once I get past the next few weeks of work, I am going to put new pads and rotors on my car all the way around. I am hoping that it will resolve a minor wobble that I have in the steering wheel under light braking. If I get on the brakes a bit more, then the wobble goes away. Not quite sure what to make of it. I almost think that the wobble is a cause of the ABS gripping the rotors too much when I brake, resulting in the pads gripping and then releasing and the timing is such that as one wheel is being applied, the other is released and vice versa. If it was a warped rotor, it should be there regardless of how hard I step on the brake. The only other thing I have heard it could be is camber shudder. But ,that would mean I have a bad front wheel bearing and my tire is straight up and down and I am not seeing odd tire wear. C'est la vie.

 

You pushed the rear pistons in? These rear pistons are screw in pistons. You do not open the bleed valve to push them back. This can ruin the calipers.

 

Thanks guys I really appreciate all the info and help. The brakes seem pretty strong now. But i do plan on using the e-brake all the time now when i park the car. Again guys i appreciate all you've said. I feel comfortable coming on this forum and asking questions and believe I will be given great and usable advice. Jaybird511jh

 

Rummy, you are correct in that you do not "just push the rear caliper pistons in". They are a screw in type piston. Since he does not do his own brake service, I didn't want to muddy the waters with that detail. There are times where too much detail just leads to more confusion.

 

jaybird, I kinda wish that you lived closer to me. We could do some of this work together and in the process you learn some about your car. A lot of stuff can be done on our cars with basic tools and a bit of knowledge.

 

Is there anything special or what to watch out for in bleeding the brakes? I might give that a try as in many years ago my brother and I would do it.

 

jaybird, I do the brakes by myself, so, my method is probably a little different than others, but there is also a little bit of reason behind it. I start off with a piece of clear tygon tubing that is about 4-5 feet long. It needs to be long enough to go from the caliper to the top of the wheel well, and back to the ground. I then attach the tygon to the bleeder port and then masking tape the tygon to the top of the wheel well (leaving a gap in the tap so I can see the highest point) and then running the tygon into a glass jar. This is where you will find 2 trains of thought and as I see it, pick the method that you think works best. Option one is to fill the brake fluid reservoir with new fluid and keep pumping the brakes as you add more fluid periodically (ensures you don't get air into the system, but will take more fluid to get fresh fluid out). Option 2 is to pump the brakes to the point that it is just above the point of sucking air, you then top off the reservoir with new fluid and repeat until you get fresh fluid out the caliper. Either way, the first caliper is going to take the most fluid. I tend to see the brake fluid go from a green color to almost clear.

Once you have clear fluid, you are now simply pumping the brakes (adding fluid as needed). You watch the top of the tube for any signs of air. If you see air there, you are still getting air out of the system. The fluid in the jar should prevent any air coming back up the tube and the tygon should fit snugly around the bleeder port. Once the tygon is air free, shut the bleeder port and move on to the next wheel. Do not forget to keep the fluid reservoir full (this is where a second person comes in handy, otherwise you will be able to pump the brakes 5-8 times before you need to add more fluid).

As for tools, you will need a jack, jack stand, socket to remove the wheel, and a 10mm wrench along with the tygon and masking tape. As for size of tygon, I seem to recall picking up 9/32" tubing. It is something right in that range. The tygon will twist the half turn or so that you need to open up the port to allow the fluid out and make sure to shut the bleeder before disconecting the tubing. Otherwise, you will most likely have to start all over on this wheel.

Doing a fluid change/bleeding the brakes is nothing special. Just don't force fluid backwards through the system. That can ruin things. I have never used one of the vacuum pumps, so, maybe someone else can speak to that. I have always kept it simple.

 

There are many brake bleeding kits on the market. This is one of the best known in the UK, not sure in the US but I'm sure there will be other, similar ones.