Hello one and all, looking for some advice. I had a very scary moment with my face lift Discovery2 the other day. I'm new to Landrover ownership and while I love the car this problem scared the crap out of me.
I'll try to explain as best as I can. While travelling down a long and very steep hill I dabbed the brakes three or four times. By the fifth dab the brake pedal was solid and I had ZERO brake. All this heading towards a junction. After taking my foot off the brake pedal for about 4 seconds I got the brake back.
Any ideas before this thing kills me?
The car has new pads, new caliper sliding pins, new discs all round and new brake fluid. I'm not overly impressed by the brakes when they are working and cant help but feel the performance of the brakes is being hindered by something. On closer inspection of the new rear discs it looks like not all of the disc is getting the full pressure of the pads as the outer half of the disc seems to get slightly corroded when left standing for a while. Not full on rusted but while the inner half of the disc is nice and shiny it seems the outer half of the disc is not as clean? Like its getting some pressure but not much?
Regards
Stinky Pants

 

How mechanical are you, how many miles on the truck, and by brand what pads and rotors did you install? Do you have any or the 4 brake warning lights on?
As for your question, Disco brake systems pump up and although it is common for the brakes to stop faster on the second pump, I have never heard of or experienced what you have described.

 

Hi Mike,
I couldnt tell you what brand they are, nothing special like Brembo I hasten to add though. The truck as 85K on it and hasn't had a hard life. All in all the new brake equipment has done about 1000 miles at most on.
Far from getting better as you pump they get worse until four or five pumps later you have nothing and a solid pedal that doesn't depress at all? I thought maybe something to do with the vacuum chamber as it seems to recharge if you leave the pedal alone for a few secs As for mechanical aptitude, a bit, nothing too serious though.
None of the usual suspects (three amigos) or any other fault lights on dash.
See link. LAND ROVER Problems - 2001 LAND ROVER DISCOVERY II Problems & Complaints - ODI #10212102
Cheers

 

I would think that your low on fluid & or have air bubbles in your system.

 

I think you're on the right thought track with the vacuum idea, I had the same thought when I read your initial post. It could be a problem with the booster, supply hose, or the check valve. In my thoughts I'd suspect the check valve first because if it was a leaking supply hose, the engine idle would be low, poor, or not at all. It could be a cracked diaphragm in the booster but that would also have a "rough idle when the brakes are applied" symptom. I've seen a few check valves fail over the years, the way to test it is to install a vacuum gauge between the engine and the valve and watch the reading in successive brake applications, a failure would be the vacuum progressively dropping with each pedal push and not immediately recovering, eventually dropping to almost nothing. Not many DIY'ers have the tools to do this at home so the options are to have a shop test it, or take the risk and replace the valve. Again, these are just my thoughts based on your description, after 40 years of working on machines I don't make blanket statements about what is wrong unless I can personally diagnose the condition. (even then I'm wrong from time to time) Good Luck

 

Cheers Mike,
I added a link to my last reply. Its not an unknown problem by the sound of it. I'll take a look into what you've written and see whats going on. Many thanks.

 

That is an ABS issue and unless your 3 amigo's light came on, not at all related to what you have described.

 

Vacuum problem. Or really leaky booster. Hear a hiss inside the car? 1 way valve on line broken?

 

If the brake fluid used is not the right dot# (not compatible), it will swell and seize the master cylinder piston. I did that mistake once on a ''76 Maverick and the brake acted exactly like you described:

The car would brake once, and the more you push the brake pedal, the less brake you get to end up with absolutely no brake at all. Yes, it was scary.

François

 

You mentioned new "caliper sliding pins"? You must be refering to caliper "guid pins"? In any event is it possible that the calipers themselves are going? Maybe one of the pistons is not working properly. Either that or maybe the pads were not installed properly. Thats the only thing I can think of which would cause the rotors to look the way you described them.