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View Full Version : Pulsing brakes again....aaand fixed!



PeterH
22nd November 2014, 02:21 PM
You may remember back a bit I had a problem with my brake rotors warping every 6 to 12 months.
After following the advice from forum members, I put a new set of rotors on, torqued the wheel nuts correctly and crossed my fingers.
Over the last few weeks I have noticed the symptoms returning, most noticeable when pulling up at lights, as it slows and specially just before stopping I could feel the braking causing the vehicle to move in a uneven speed, like a slow/fast pulsing motion.
The rotors and pads are both good quality, so I did a bit of research and found others had experienced the same issue, on Range Rovers and other vehicles.
One person had success by re-bedding the brake pads, so I thought I'd give that a shot.
I went to a nearby industrial area this morning, with a nice straight road and no one around being a weekend.
I accelerated to 60km/h and then using moderate to hardish braking force, slowed to about 5kph, (not to a dead stop). I repeated this 10 times in a row.
I was impressed with how quickly the Rangie pulled up in a dead straight line.
The idea is to get the brakes hot, then cool slightly while accelerating again, then brake again and repeat.
After this I noticed a huge improvement in the feel of the brakes, the pulsing sensation is completely gone.
My guess is there was a build up of some type on the rotors, which gets removed during the bedding in process, with the friction of the hot pads removing any contaminates.
I usually put the car in neutral at lights so I'm not applying brake force for long periods in the one spot.
I also brake fairly lightly, allowing the car to slow without using heavy braking most of the time. I'm wondering if this contributes to build up on the rotor surfaces, where heavier braking might help to keep the rotors clean.
I hope this helps someone experiencing the same problem, well worth a shot and doesn't cost a cent...ok maybe $1 in fuel...but still far cheaper and easier than replacing rotors and pads!
Cheers, Pete.

Hoges
22nd November 2014, 08:39 PM
An interesting observation... I also usually drive lightly on the brakes and coming down the "Range" from Toowoomba tend to leave it in second gear to provide the extra retardation. The vehicle has not had a lot of use this year...less than 3,000 km:( and the brakes developed a squeal. So, last time coming home from Toowoomba a couple of weeks ago there was almost no traffic on the descent so I gave the brakes a bit of a workout ... the squeal has gone and they "bite" a lot better than before!

finallyrangie
24th November 2014, 08:37 PM
I have just started to notice a squeak as I come to a stop, pads and rotors less than 5k old, I am definitely going to give the ' bedding in' a try, thanks for posting the tip

poleonpom
24th November 2014, 10:10 PM
Hey Peter, did I read somewhere that you have replaced the brake lines? If not pulsing brakes could be down to flexing brake lines

chopper
25th November 2014, 09:49 AM
Hey Peter, did I read somewhere that you have replaced the brake lines? If not pulsing brakes could be down to flexing brake lines

That's like saying a spring makes a car bounce up and down.

PeterH
25th November 2014, 06:04 PM
Hi poleonpom, yes I followed your lead and replaced the brake hoses.
That definitely improved the feel of the brakes, and also lessened the effect of the pulsing, (probably due to the old brake hoses flexing as you suggested), but the core problem seems to have been a build up on the rotors.
Did you know there are 6 hoses in total? A couple of short ones above the rear wheel wells.
Cheers, Pete.

poleonpom
25th November 2014, 08:33 PM
6 makes sense. I replaced mine a while back and only remember that I got more than 4. I thought it was 5, but now you mention it, 6 makes sense. Glad to hear your brakes are performing.
Jonathan

TheTree
25th November 2014, 08:44 PM
6 makes sense. I replaced mine a while back and only remember that I got more than 4. I thought it was 5, but now you mention it, 6 makes sense. Glad to hear your brakes are performing.
Jonathan

Early models seem to have 5 and then it changed to 6 from VA346794

As per this thread ;)

http://www.aulro.com/afvb/p38a-range-rover/209761-5th-brake-hose-who-knew.html

Steve

daf11e
25th November 2014, 08:52 PM
Is the pulsating experienced after driving a while and brakes warm up or straight away?.....mine pulsate after about 15 to 20 minutes of driving....rotors and pads have been replaced.....I will definitely try this bedding method.
Also would caliper pins sticking have this effect?.......thanks.

PeterH
26th November 2014, 06:59 PM
I'm pretty sure it was pulsing from cold, possibly a bit worse after being driven for a while though.
Caliper pins sticking could mean only one of the pads is doing all the braking, it's my thinking that if all the braking force was coming from one side and not the other, it would have to eventually affect the rotor in some way, possibly causing a warping/out of shape issue.
If you suspect your caliper pins are sticking, it's a pretty easy job to check them for piece of mind.

daf11e
26th November 2014, 07:02 PM
Thanks Peter I'll do both the pins and bedding .