Thread: Bleeding Defender Brakes - Any secrets ?

If, while bleeding the brakes, you have pushed the pedal right to the floor, the seals in the master cylinder are run through a section of the cylinder they don't normally touch. This 'unwiped' section of the cylinder may have corrosion or some build up that can damage the master cylinder seals during the bleeding process, making it impossible to get a decent pedal.
I have always bled brakes by using one of the 'one-person' bleed units readily available from repco or the likes, and only taking the pedal through its normal stroke.
Good luck,
Martin

I had similar problems with mine about 18 months ago. Mine is a Td5 with ABS but after replacing the Master cylinder and the ABS Modulator and overhauling the front calipers plus trying every system of bleeding known to man, the eventual fix was achieved by removing (without disconnecting the hydraulics, placing an appropriate sized spacer between the pistons and then bleeding with the bleed nipple at the highest point - when fitted, there is a possible air space above the nipple. Needless to say that this solution was achieved by me but by a highly qualified engineer who has designed and built numerous special vehicles based on Land Rovers.

The symtoms I had were a spongy pedal to the extent that if pressure was held on the pedal, it would gradually go right to the floor - with no loss of fluid from the system.
The problem reared its ugley head after I replaced both the front and rear axles - complete, hub to hub.

A test that can be done to detect where the problem is to clamp off individual wheels/calipers or pairs of calipers (both rear or both front). If pedal comes good then problem has been isolated to area that has been clamped off.

Hope you sort it out soon.

Originally Posted by marting

If, while bleeding the brakes, you have pushed the pedal right to the floor, the seals in the master cylinder are run through a section of the cylinder they don't normally touch. This 'unwiped' section of the cylinder may have corrosion or some build up that can damage the master cylinder seals during the bleeding process, making it impossible to get a decent pedal.
I have always bled brakes by using one of the 'one-person' bleed units readily available from repco or the likes, and only taking the pedal through its normal stroke.
Good luck,
Martin

Agree with this and this is what I thought had caused my problem and why I replaced the master cylinder but alas, in my case it was not the problem. So I now have a spare used master cylinder sitting on the shelf.

just got on here to post the same question! replaced rear brakes.(pads and rotors) and new master cylinder. bled several times and feels good then start up and brakes are nothing. pump a few times and then they are fine, but after 5min of driving hit the brakes and almost to the floor again and hardly anything.
no fluid loss and no air in system when bleeding got me puzzled aswell.

Strange thing the other day was the pedal was as hard as hard, soon as hit the pedal brakes on, like this for about 30min of driving then when i started up again went back to soft nothingness.

Unless you were changing fluid due to age/contamination, did you really need to bleed ?

They are a **** of a thing to bleed, the hardest of any system I've ever tried.

In the finish I made a pressure bleeder, it was the only way I can get the air out and get a decent pedal, I'd reckon a vacuum bleeder would be even better.

I tried bleeding the way we always bled race car systems and that wouldn't work, (effective on any race car I ever worked on) so tried the old fashioned pump the pedal and hold and that didn't work either, so whenever I need to bleed I use the pressure bleeder.
If I had a vacuum bleeder I'd use that instead, It'd probably be even more effective.

How much fluid are you pushing through ?
Are you starting at the longest line first ?

Have you tried doing a complete end or even four wheels at a time ?
This is how race car systems are bled and what I try and do on Deefer except I use the pressure bleeder. ie. I open all four calipers and pump the fluid through. Seems to work, and you get all the old stuff out quickly.

started at front drivers side as (rave) says then worked to the back. even did the back first then came to the front. putting through about 300-400ml of fluid per bleed.

rang a brake place the other day and they said "oh they are easy never any troubles with them. but cant help you for 2weeks" so i just make sure i pump the brakes a bit before getting into town. or park out of town a bit.

Originally Posted by tazd

started at front drivers side as (rave) says then worked to the back. even did the back first then came to the front. putting through about 300-400ml of fluid per bleed.

rang a brake place the other day and they said "oh they are easy never any troubles with them. but cant help you for 2weeks" so i just make sure i pump the brakes a bit before getting into town. or park out of town a bit.

I was always told to start at the rear passanger side then drivers side rear then front passanger then final drives side front.

Originally Posted by scott oz

I was always told to start at the rear passanger side then drivers side rear then front passanger then final drives side front.

x2.