2002, TD4-Brake bleeding problem

:behindsofa:

Right...Have done a Freelander related search and can't find anything specific to my query.
I am giving the Freelander a seeing to prior to the MOT in April. Have changed all the oils and filters etc., replaced brake shoes, pads and front discs. I decided to replace the brake fluid and all went well until it came to the rear brake bleed nipples-the hexagons were rusted and I couldn't even release them with a good pair of vice grips. Bought two brand new wheel cylinders and also replaced the solid brake lines to each one (From the flexible hose). I clamped the hoses whilst doing the work. The cylinders were fitted with the bleed nipples at the top..same as the originals. The cylinder pistons were clamped fully in and the hose clamps released. The L.H. cylinder bled a treat but the R.H. one just keeps giving a stream of bubbles followed by a clear flow, then more bubbles.
I am using a pressure bleed kit that has been used for many years without problems and I have used it on a variety of cars with superb results. I use it at 20-25 p.s.i.
The pedal is firm and does not creep to the floor-the brakes work fine and the car does not "Pull" to one side when the brakes are applied.
I followed the unusual method of bleeding as laid out in RAVE and Haynes (Front left>Front right>Rear left>Rear right). The flares on the new solid pipes are good and sealing as they should, there are no leaks or loss of fluid.
Any advice would be most welcome

UPDATE.....

As per my post, I was hitting a brick wall with bleeding one side :deadhorse:

Whilst I had the car up in the air, I decided to have another go.
I clamped the flexible hose off, removed the bleed nipple and put a few wraps of PTFE tape (Cost pennies from a plumbers merchant, B & Q etc.) on the threads, leaving the pointed end and the hole clear. Set up the pressure bleeder etc. released the clamp and hey presto, one big bubble and job done.
Obviously the threads on the bleed nipple were a bit slack and air was being drawn in past them-the PTFE tape stopped this from happening.

i would change the cylinder on that side they do not cost a lot ptf is fine around the house ect: buty on high pressure things like brakes i just would not trust it , but that is me .

teddywood1 said:

i would change the cylinder on that side they do not cost a lot ptf is fine around the house ect: buty on high pressure things like brakes i just would not trust it , but that is me .

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:behindsofa:


It's a brand new genuine LR Cylinder. I bought two from a main dealer and fitted them both sides.
I have a nice hard pedal without any sponginess.
The PTFE sealed the threads during bleeding and is not in contact with the cone ended seal on the screw and the fluid.
I used it to stop the ingress of air past the threads and nothing else. If anything, the application of PTFE tape on the threads alone...Nowhere else would probably prevent the problem of corrosion caused by dissimilar metals and sezure of such items.
I have worked on brakes for many years and feel confident that no risk to the performance/safety aspect of the braking system has been caused.

I've always been taught to never clamp brake hoses, even the flexible ones, because most are armoured inside and you can crush the armour. Obviously you've sorted it now, so not a problem.

fair do's to you for sorting it Irish, certainly don't want to be the voice of doom, but, will the brake fluid react / degrade the ptfe in some way ?

The fluid is not in contact with the ptfe - the end of the bleed nipple is a cone shape that fits against a cane-shaped depression in the wheel cylinder. When the nipple is tightened it is this that makes the seal. He has fitted the tape to the thread to prevent air being drawn back through the threads when bleeding. Zero risk, and actually quite a common problem to have.

dave21478 said:

The fluid is not in contact with the ptfe - the end of the bleed nipple is a cone shape that fits against a cane-shaped depression in the wheel cylinder. When the nipple is tightened it is this that makes the seal. He has fitted the tape to the thread to prevent air being drawn back through the threads when bleeding. Zero risk, and actually quite a common problem to have.

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I'm sure it's this that has caused a similar problem on the rear calipers of two vectras I have worked on. It seemed as tho it was compressing air and not releasing the piston fully when the pedal was released, then when bleeding you would get a load of tiny bubbles and then nothing. Nipped it back up, same again. Eventually tightening up the bleed nipple to ridiculous torques sorted it. I feel for the guys who had to sort it next time.

mick 1986 said:

I've always been taught to never clamp brake hoses, even the flexible ones, because most are armoured inside and you can crush the armour. Obviously you've sorted it now, so not a problem.

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Did you use to try clamping solid brake pipes before someone taught you that?
I wonder why Haynes etc tell you to use clamps on flexible pipes.

Richard Martin said:

Did you use to try clamping solid brake pipes before someone taught you that?
I wonder why Haynes etc tell you to use clamps on flexible pipes.

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Never clamped a single brake hose in my life mate, seen #### nuts clamp both flexi and solid. The guy who taught me always said its no real hard ship to bleed a system properly.

id say clamping flexi just enough to stop fluid loss or air entering is the best way where ever possible ,reduces the risk to master cylinder seals

Clamping if done properly does not mean applying mega force to the hose...just enough to close the bore and stop the fluid leaking through and emptying the master cylinder whilst work is carried out on a particular section of the system. Brake line clamps (For hoses) have been around for years and are in common use in garages...including Main Stealers.
As has been posted by others, the PTFE tape was NOT applied to the whole of the nipple, just the threads. The threads are not in contact with the brake fluid-except when bleeding and there is zero risk of contamination. If Land Rover got their act together regarding specification, the threads would be a better fit. People go on about Britpart quality but LR are no better in many products.