RangeRovers.net Forum banner

1 - 5 of 5 Posts

·
Registered
2006-2009 Range Rover MkIII / L322
Joined
·
13 Posts
Discussion Starter #1
Hello all and Happy Holidays. I purchased my '07 RRSC a little over a year ago. When I drove it, sometimes the brake pedal went spongy, travelling about 2/3 before wanting to make the vehicle stop. It was intermittent, maybe happening once a month to once every 6 weeks. I just pumped the brakes and it all went back to normal. I checked the pads & rotors and at the time they did not need to be replaced. I recently replaced all 4 pads and now the spongy feel is consistent. I even bled the brakes and still spongy. I took it to the dealer to have it checked out. I was told that it is probably the master cylinder going bad since the pistons were pushed all the way in forcing fluid back into the reservoir and sometimes that makes the master cylinder go bad. Is that really true? I have changed many brake pads and components in my life (not professionally) and I have never heard of this or had it happen to me before. HAs anyone else had this issue before? I'd just like to know before I order a new master cylinder. Thank you all for your input. -Key
 

·
Registered
2016-2018 Range Rover MkIV / L405
Joined
·
321 Posts
I would start by changing the brake fluid out and doing a complete & proper bleed. I just did our front brakes about three days ago, pads & rotors...all OEM parts...no sponge feel. You have the SC...on the Brembo front brakes (I haven't changed the rears, not sure if they're the same), I'm sure you noticed, but in case you didn't, there's a bleed port on the inboard and the outboard of each caliper set...two per wheel/corner...I'd ensure you bleed them properly one final time, with fresh fluid, prior to spending money on a new master cylinder.
 

·
Registered
2002-2005 Range Rover MkIII / L322
Joined
·
88 Posts
as fosterelli stated, replace all of the fluid. fluid accumulates moisture regardless of how well you maintain it.
ruins the fluid. goofs up it's characteristics. flush the entire system from the reservoir out and bleed the calipers
as you would any caliper'd car. that's cost like 20 bucks. try that first. then go from there.
 

·
Premium Member
Joined
·
2,467 Posts
Generally speaking, no, pushing fluid back through the master will not cause any issues, however, if the seals inside there are on their way out already(possibly what caused the random lack of braking force previously) it can cause it to fail at once.

These masters don't fail very often, and when they do, it is usually from the fluid getting real bad, and contaminating the seals. If the seals/bores are not damaged, and just have fluid passing by them from contamination, a pressurized flush can clean them up.

I agree, I would start by bleeding them out completely, but if that doesn't take care of it, might want to try to find a shop that does pressurized flushes, and give it a shot. But then again, I don't remember the master being that pricey on this(<$200 I believe), so might be worth replacing it, as a full flush will probably cost you around $100 at a shop, and would need to be repeated after the master is replaced.
 
1 - 5 of 5 Posts
Top