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darkcyde

New Member
Hi

I know there are loads of existing threads on this, and I have been reading them but nothing really helped diagnose my problem.

My brake pedal travels quite far (about 3/4 of the way to the floor) before any noticable braking occurs. But when you pump the pedal, the pressure comes back again, only to fade again if you rest your foot on the brakes.

I've had all fours wheels off, changed all the pads and shoes and checked everything over. Fluid level is fine, one of the rear cylinders had a slight bit of fluid leak, but serious enough to worry about just yet.

If you pump the pedal and then switch the engine off, the pressure stays until you switch the engine on again.

If you press the pedal whilst starting the engine, you can feel the pedal get softer under your foot.

I'm thinking it's the vacuum pump? Any other ideas?

Thanks in advance!
 
Definitely sounds like air getting into system, so it needs bleeding and checking for leaks, splits in hoses, rusty pipes etc etc. Possibly a vacuum pump problem, but sort the bleeding out first.
 
to find out what end is giving the trouble try to clamp the flexi pipes one by one if the pedal gets better after you clamped one pipe you can work out where your problem is
 
i rekon its the master cylinder.

As you pump it up it empties the servo, and you switch off the engine. You then start the engine, it pumps up the servo and pulls the master cylinder down through the fluid.

Seals will have gone in it.

Also the drums will need adjusting a bit, jack up each back wheel in turn, spin the wheel and turn the adjuster until it binds, then back it off a bit.
 
does not sound like vaccum pump. check all the above and then maybe your wheel bearings? if these are loose, can cause problems with braking.

G
 
I re-adjusted the shoes this morning after reading someone else's thread who had the same problem - they did that and it made it better, but it still failed the MoT. Unfortunately, he's not come back to say what the fix actually was.

I re-assembled everything in exactly the same way it came off, and the problem occured before I took it apart, and there has been no change for the better or worse, so I think it's assembled right.

I've been all over the brake system and can't find any sign of leakage, and the fluid level hasn't changed at all.

Getting a little disheartened with this Defender - in the last 8 months it's had....

Shocks
Coils
Starter Motor
Battery
Alternator
Steering rod arms and ball joints
Clutch slave cylinder (2 because the first replacement was leaking)
4 Tyres

And it still needs a new steering box as it's p*ssing fluid (tried the capful of DOT 4 but no joy)

:( :( :( :( :(

Think I may have to try replacing the master cylinder - need it working 100% ASAP as I use it for my business vehicle so don't have a lot of time to investigate. At least a Master Cyl is cheaper than a vac pump!
 
darkcyde said:
I re-assembled everything in exactly the same way it came off, and the problem occured before I took it apart, and there has been no change for the better or worse, so I think it's assembled right.
Click to expand...

have the brakes ever worked correctly ?

just because you've put it back the way it was before doesn't mean that it was correctly assembled previously - find a manual or check rave for the correct assembly as fitting the springs incorrectly will produce exactly the issues you have mentioned
 
I Had a similar problem after changing my shoes so I changed the master cylinder, pipes, callipers and slave cylinders. Then I gave up and took it round the garage and the shoes were round the wrong way. expensive f**k up ay kicked myself for weeks after that one then the wife started.
 
LOL - yeah, I see how that could be frustrating!

Well, the brakes have been fine up till recently, and both sides were assembled in exactly the same way, and I have copied the assembly when I put it all back together.

One end of the shoe bracket had a slightly longer piece that had a slight dip which fitted exactly into the cylinder piston, and the other end fitted perfectly into the retaining clip, so I think it's right but will check the manual.

Is a Rave manual better than Haynes?
 
Ok, I've changed out the Master Cylinder and the Servo unit, and also changed the rear cylinder with the slight leak.

Pumped new fluid through the whole system as the old reservoir had quite a bit of junk in it - did notice that in one leg of the pipework the fluid was white and milky, like it was contaminated.

Anyway, did all this, bled it completely, readjusted the rear drums, and it's better but the pedal still travels a bit, and you can still pump it solid with a few presses. Once it's up the brakes are brilliant, but it soon goes again.

Also, if you rest your foot lightly on the pedal, you can feel it fading beneath your foot.

Don't get me wrong, it is better but I think that may be down to the change of fluid more than anything.

Any more ideas? The only thing left I guess is the vacuum pump.

[POST DUPLICATED IN ANOTHER THREAD]
 
Mine does exactly this. As does the wifeys 90. I think it is the adjustement of the rear shoes and part of the character of defender brakes.
Annoying but not something to throw tons of time and money at, unless you can't stop before you hit something.:D
 
I've got this problem too. Brakes work low down ok but a quick up and down and it bites much further up the pedal. And also you can feel the pedal move down under pressure with engine on as you say.

Did you fix this in the end?
 
adjusted them earlier but made no difference.

Will have another look tomorrow.

Internet isnt throwing anything up (or rather throwing everything up).

This thread needs a conclusion 3 years on. ::)
 
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