Lately I noticed that the brake pedal travel in my 2011 XKR seems a bit longer than it should be. It may be due to a mental comparison with my XJL, but it just doesn't seem right. Brake fluid is full, and I have not noticed any leaks or fluid drops in the garage. I tend to drive each car as a primary driver every other week, and this is the XKR's week to play. Am I just noticing the difference, or is there possibly something I need to have addressed? I did have the brakes "inspected" a few months back, and both rotors and pads were all perfectly fine and suitable for thousands of miles, so I do not believe that is where the problem lies. The car still has under 25,000 miles.

 

You may not have a problem as you note. Worn pads will cause some travel and when that happens, you will see less fluid in the reservoir. You've already checked the pads and fluid so that's not it. If you apply the brake and the pedal slowly continues to travel to the floor, you have an issue with the master cylinder.

 

Maybe just need bleeding, or indeed the fluid needs changing...which IIRC should be every 2yrs due to the hydroscopic nature of the beast.

When was the fluid last changed?

 

It was back in July 2013, at 11,000 miles.

 

That's the issue. Air got into the system.

 

More specifically moisture.

The more I read forums the more I am amazed at the lack of the most rudimentary of automotive knowledge.

'Jeffrey' in the UK is an old name, and one not held by many under 60. If the OP is of that age group he should be ashamed of not changing his brake fluid every 2yrs...but at least he's learnt sommat new...which he will (hopefully) retain

 

Moisture meter https://www.ebay.co.uk/itm/Brake-Flu...23025607274&ha

 

Air in the system would result in a softer pedal dropping more easily.

Water in the system may have no initial symptom as it would work while it is cool enough not to boil. If one drives gently/normally, one wouldn't know. I'm sure many people drive old cars with the original brake fluid in it Only under hard use does the water boil and form bubbles resulting in a reduction of brake pressure. The day-to-day problem is more that the water will accelerate corrosion as would the fact any inhibitors in the brake fluid have long been used up.

If the pedal has suddenly gone soft/long, one should check the system over and in this case change the fluid too to get a new baseline. 5 years is a bit long

It doesn't take much air to make the pedal very soft, as I found out last weekend before my TÜV appointment. A second flush and one small slug of air came out restoring the pedal back to its normal high and firm state.

 

neilr thanks for explaining what I was lazily insinuating. Air was not evacuated on the last fluid change.
Even with a fluid change, you will have to work very hard to get all the air out. Not easy.


I must share this story as it might prove helpful to this problem.
I consider myself somewhat proficient and through, done every aspect of brakes on all my cars. Even modified the proportioning.
Had to take my Chevy to a pro to change timing as it has no manual adjustment.
He said the brakes had too much travel in it. I got apprehensive at first, as it has always been that way, then said ok, lets see if you can improve it.
I spent an hour with him pumping the brakes. It seemed stupid at the moment. Like we were trying to milk a bull.
I now consider myself totally dumb when it comes to brakes. Its twice as good and perfect. And this particular brake system is famous for its excessive pedal travel.

 

The superior DIY process for bleed/changing brake systems is to use a vacuum pump. There are many Youtube videos detailing the process. I purchased a kit at Harbor Freight that is powered by my aircompressor and makes it easily a one person job.
As many know, the old school method requirig two people works well too but the vacuum pump is king in my book.
Of course, having a shop do it is by far easier, but much less rewarding.

 

My guy had one that pumps fluid through the system. But did not use it.
Please post a link to your device. I will buy it today. And describe your method.

I know some guys swear on pulling fresh fluid up through the bleeders.

Thanks in advance

 

So far mine was done by the dealer but I'll be needing to do a fluid change next year. On my other cars I would buy Speed Bleeders and do it myself. With those cars I would use a different color brake fluid and bleed the system. 1st just turkey baster out the fluid in the brake container and fill with new fluid. Then crack the back right and pump bleed the system. Worked great and do back lfet , front right and front left and you're done. Now I have a question that so far I can't fine and that is : what is the thread size for the standard XKR 2010-2015 brake bleeder nipples. Does anyone have that info.

 

Jagtoes I would strongly recommend you avoid Speed Bleeders.
No one I know has been happy with them in the long run.

 

Interesting as I've used them on 5 of my last cars and they work great. Do you know what their complaints were. Never had a problem yet so time will tell.

 

The Speed Bleeder website leads to a part # SB1010S for the front brakes (doesn't list anything for the rear).
The SB1010S has a metric size of M10 X 1.0

 

Hi There,
One thing to consider is that Brake Fluid is hygroscopic so can and will absorb moisture over time. As the moisture is not compressible it can appear that the brakes are soft and/or there is more travel on the pedal. It's generally recommended to replace the brake fluid every two years.
Cheers,
Cubist

 

They are weaker. If you bleed regularly you wont have a problem, they will snap if left in place at length where they salt the road. Not the end of the world, you can use an easy-out but now you have tons of air in the system.
Plus some air gets past the tread wen you loosen them and walk back to pump the pedal and then back to tighten.

Check out this corvette forum, they all swore off the speed bleeders https://www.corvetteforum.com/forums...-bleeders.html

 

I've used Speed Bleeders on my XK without problems; and it is easy with the bleeders as its a one person job. The folks at Speed Bleeder (web site above, I think) were knowledgeable and can provide you with all the info you need regarding the XK. Not particularly expensive, either.
So +! for Jagtoes/Speed Bleeders.

 

I didn't see much on the form that would convince me to not use them. Looked like wrong parts or improper tightening . As I mentioned they worked on my past cars so I don't see a problem with them. Just a matter of opinion I guess. If I ever have a problem with them I'll post what it was.

 

This worked like a champ! I've used it on 4 vehicles so far.

https://www.harborfreight.com/brake-...der-92924.html