• Welcome to the Land Rover UK Forums

    You are currently viewing the site as a guest and some content may not be available to you.

    Registration is quick and easy and will give you full access to the site and allow you to ask questions or make comments and join in on the conversation. If you would like to register then please Register Now

Correct way to bleed brakes

amun1000

amun1000

Offroader
OK I was messing about with the brakes over the weekend - and decided to read the Haynes manual on the above.
Haynes recommend the 'assistant' press the brake pedal with one full stroke and then three quick short ones and lets the brake pedal return to its original position.
However my normal operation is to pump the brake 2-3 times and keep it depressed until the nipple tightened. Only then can the assistant release the pedal.
I used Haynes method but now iI find the brakes softer than before.

I would like to point out that I did change pads on the front as well so some of the softness be apportioned to the new pads 'bedding' themselves in.

does anyone have any experience of using the 'Haynes technique'?


TIA


Andrew
 
Yes, and it's complete b*****ks.

Use an EziBleed or slow pedal movements, closing the nipple before every pedal return. Vacuum bleeding systems are reputed not to work well.

If you're bleeding 109 11" brakes, the dual front cylinders are very difficult to bleed properly (not the type worked on in the "Book of Lies", so they have no idea) because the inlet and outlet ports are at the 3/9 o'clock position, which creates an air trap in the top half of the cylinder. There are 2 ways of bleeding these; one short which does and adequate job, and one long which does a very good job. Both require removal of the drum.

The short way is to push the pistons as far back into their bores as possible and clamp them, minimising the size of te air trap before bleeding.

The better way (and only way to eliminate the air completely), is to remove the drum, hub and finally the brake backplate from the axle. Then turn the backplate so that it lies horiontally, with the pipes uppermost and shoes/cylinders below. The ports are now at the top of each cylinder, allowing full bleeding. Long winded, but worth it in my experience.
 
Guessing now but.......

Does the Haynes method create a small amount of pressure in the system so that the fluid is pushed out when you open the nipple.

Personally I use the assistant to pump the pedal a few times and then push the pedal down while I open the nipple. When they hit the bottom of pedal travel I shut the nipple and then they allow the pedal to return to the normal possition.
With this method I find you get a good squirt of fluid out of the nipple and any air is quickly got rid of.
 
NeilB said:
Guessing now but.......

Does the Haynes method create a small amount of pressure in the system so that the fluid is pushed out when you open the nipple.

Personally I use the assistant to pump the pedal a few times and then push the pedal down while I open the nipple. When they hit the bottom of pedal travel I shut the nipple and then they allow the pedal to return to the normal possition.
With this method I find you get a good squirt of fluid out of the nipple and any air is quickly got rid of.
Click to expand...

This is the way I normally do it, but have the nipple open when the pedal is depressed, but thinking about it I think your way is better as this does not allow any back-draft into the system.


Cheers
 
easi-bleed works wonders; not so sure about the tls on lwb brakes tho' have heard there are a PITA.

generally open about same time as assitant pushed down, close then assitant lift off pedal is the way.
 
A tip for you all,
If the pedal is just a bit soft after bleeding and you can't get it any better, press the pedal down hard and keep it jammed down with a piece af wood. Leave it like this overnight and I guarantee that the pedal will be rock hard in the morning (subject to correct adjustment of the brakes). Ill leave it to you to guess why this happens!
 
burrell8nhp said:
A tip for you all,
If the pedal is just a bit soft after bleeding and you can't get it any better, press the pedal down hard and keep it jammed down with a piece af wood. Leave it like this overnight and I guarantee that the pedal will be rock hard in the morning (subject to correct adjustment of the brakes). Ill leave it to you to guess why this happens!
Click to expand...

Something to do with air being lighter than fluid ;)
 
Hi all
I bled the front brakes on my 109 using the Ezibleed system and got a good firm pedal within 2 minutes. Realy simple and effective.


PS may just be me but why does the pedal go hard overnight ????

Whoops forgot to sign off

Dave 109
 
burrell8nhp said:
A tip for you all,
If the pedal is just a bit soft after bleeding and you can't get it any better, press the pedal down hard and keep it jammed down with a piece af wood. Leave it like this overnight and I guarantee that the pedal will be rock hard in the morning (subject to correct adjustment of the brakes). Ill leave it to you to guess why this happens!
Click to expand...


Do they stay hard forever?

I can't see how the air bubbles can rise (through the master cylinder into the reservoir?) just because they are under pressure when they won't when not under pressure.
Or can they seep very slowly past the seals in the wheel cylinders?

Or do they dissolve in the fluid when under pressure and then work their way out as the fluid goes back and forth under normal breaking??

Put me out of my misery and tell me why??

BJ
 
BigJim said:
Do they stay hard forever?

I can't see how the air bubbles can rise (through the master cylinder into the reservoir?) just because they are under pressure when they won't when not under pressure.
Or can they seep very slowly past the seals in the wheel cylinders?

Or do they dissolve in the fluid when under pressure and then work their way out as the fluid goes back and forth under normal breaking??

Put me out of my misery and tell me why??

BJ
Click to expand...



Your getting very warm!!!
 
I've read somewhere that filling a large hypodermic syringe with brake fluid and connecting (via a piece of tubing) to the bleed nipple (then, with the bleed nipple slackened) allows you to SLOWLY force fluid/ air bubbles up into the reservoir (reduce the level first to allow for this!). Then tighten the bleed nipple and (apparently) job done. I've not actually tried this yet, but sounds like it should work - what do you think?
 
Hotshot, you're spot on about the reverse bleeding method. I wish I could have used it on Eudora, our '77 SWB series 3 when I replaced the whole brake system.

Biggest problem is getting a big syringe. I tried all the usual car places and paint places like B&Q but I got blank stares everywhere I tried.

I used to have a friend who's a vet. She'd probably have been a good bet we've lost touch :( .
 
I've read so many postings on the perils of brake bleeding that I'm dreading the first time I have to do Emma's (109 ex-mil). This last couple of posts is the first time I've seen what appears to be a glimmer of hope. Wouldn't it be possible to use an oil syringe for squirting the fluid in? Would the same method work for clutch fluid replacement?

Failing that: how about an icing syringe? (don't tell the wife, though).
 
Lampsh - yup, they would work but the problem is that the length of pipe on the end is far too wide for the bleed nipple. A large syringe is ideal because a length of silicone fish pump tubing would fit the nipple and the syringe perfectly.
 
lampsh said:
I've read so many postings on the perils of brake bleeding that I'm dreading the first time I have to do Emma's (109 ex-mil). This last couple of posts is the first time I've seen what appears to be a glimmer of hope. Wouldn't it be possible to use an oil syringe for squirting the fluid in? Would the same method work for clutch fluid replacement?

Failing that: how about an icing syringe? (don't tell the wife, though).
Click to expand...

Why can't you use an easybleed in reverse? Connect the tube that goes to the reservoir to the nipple???
 
Son of 669wood said:
Lampsh - yup, they would work but the problem is that the length of pipe on the end is far too wide for the bleed nipple. A large syringe is ideal because a length of silicone fish pump tubing would fit the nipple and the syringe perfectly.
Click to expand...
On the twin front cylinder system, where the bleed nipple is in the bottom cylinder,
I use a new oil can full of brake fluid, , bleed tube on the nippy, other end pushed over the spout on the oil can,
The oil can when pumped then reverse bleeds the system, pushing the air bubble up to the reservoir,
This is then a one man job, just like in the land-rover factory
 
Back
Top Bottom