Classic cars forum & vehicle restoration.

[Fluffle-Valve]

Been having trouble with the brakes on my old Series III. I fixed a leaking front slave cylinder and then I couldn't get any pedal when bleeding them. So after a few questions asked on the Series II club forum, a few different ideas on bleeding were mentioned.

So Yesterday, my mate Stuart and I set too and spent some time to sort my bleeding Brakes out. We took all the wheels off, drums off and brake shoes off. I then clamped the slave cylinder pistons in with some G-Clamps. Then starting at the farthest nipple, we proceeded to bleed away the old fashioned way with Stuart pumping the brake pedal and yours truly, working the nipples... Once I was happy with the bleeding process and that there was no air coming through the system, we De-clamped and fitted the brake shoes back on. This time I got the correct shoes on the right way round on the rears. I’ve had two of the same shoes on the off-side for I don’t know how long? I have now fitted new shoes to the rear. We adjusted them up and then took the old gal out for a test drive. After a couple of times around the block, testing the brakes and getting them warmed up, I found that they were 99.9% perfect. Hit the middle pedal and all pulled up in a straight line. We were so happy with it, Stuart did a short video showing me letting go of the steering wheel and braking at the same time.

Me is a proper well happy chap now and many thanks goes to Stuart for giving his day up to come and help me sort them dam brakes out.

Here's how straight they pull up. Very Short Video.
http://www.youtube.com/watch?v=FPdKQqc0xdE&feature=share&list=UUF61DLc5SitDApamZWUhRvg
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Series 3 1972 LWB Truck Cab Pick Up. My daily drive.

[34HF90]

Nothing better than when they're working right . Many people complain endlessly about Land Rover brakes- especially about TLS bleeding.

I have found over the years that when properly adjusted, a TLS drum brake in good condition is a very effective device. I'm sure that many of the problems occur through maladjustment and/or disuse. Even slightly sticky pistons can give an inordinate amount of trouble- both in use and when bleeding.

Keeping the pistons clamped up is a good idea that seems to work when trying to get the air out, but I usually find that leaving the drums on and backing the adusters off (thus allowing the return springs to do the job) is usually enough PROVIDED the cylinders are absolutely free. Again, any hint of refusal to push all the way back results in stubborn air bubbles.

The other big problem is the shoe post setting. Often overlooked, but it makes a huge difference to the overall performance and balance

Glad you got it sorted

[Jim.Walker]

I'm not familiar with Land Rover braking systems, But I do know that many, many people used to come unstuck bleeding GIRLING twin leading shoe drum brakes where adjustment was by snail cam.
If the slave pistons were at all extended as they would be if shoes are at all worn, Air in the large air space under the piston in the slave cylinder allows fluid to by-pass the air without disturbing it giving the impression the cylinder is properly bled.
Often, BACKING OFF the snail cam adjustor (the OPPOSITE of the normal practice of lockig up adjustors) is enough. But sometimes drum removal so that the shoes can be clamped "off" as far as possible is necessary. A large "G" clamp or these dys perhaps a tie-wrap.
In the days of the typical BMC/Girling front brake system such as A55s etc. our garage could almost have successfully specialised in bleeding such brakes for embarassed D.I.Y.ers who could not get their brakes to work. Especially as they were happy to pay a fiver (for somthing which took about 15 minutes) when the hourly rate was only half of that just to get their car working.!
Jim.
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Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[RUSTON]

Some of the BMC light trucks that used the Girling setup were were bad bleeders as well, we used to raise the front of the truck as high as possible which helped a little. No such problems with Lockheed systems though, they usually bled straight away possibly due to the fact that the adjusters were snail cams on the actual cylinder which kept the pressure on the pistons.

Pete.
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Measure twice...cut once!

[Jim.Walker]

Spot on Pete. It was only the system which had the snail cam adjustment pivoting in the in the backplate which caused problems. Really from a lack of appreciation of the effect.
Where the adjustor was between the shoe end and piston they need to be adjusted up (and preferably enough to lock the drum). Some of this type were snail adjustors and others were a screw and collar. I cannot rember whether either of these were Girling, but I think not.
Jim.
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Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[Kelsham]

I had a series Landrover with single leading shoe setup.

I found that I was unable to cure a spongy pedal. Changed linings, wheel cylinders, and master cylinder.

Two cans of brake fluid later and I still had air in the system.

Eventually I removed the drums and clamped the pistons closed. Voila the pedal went firm.

Regards Kels.

[Jim.Walker]

There can be problems with bleeding disc brake calipers on any vehicle because of the same problem.
In a brake pipe there is insufficient cross sectional area to allow fluid to squeeze past an air bubble, so the air is pushed ahead of the fluid. Simples (as I heard somewhere and common sense)
If a piston in a slave cylinder of ANY hydraulic system is partly extended fluid can by-pass air trapped at the highest point so that fluid issues from the bleed nipple as if all air has been expelled.
I have found over the years that if bleeding leaves a spongy pedal the answer is inevitaby to make sure ALL pistons are pressed back into their cylinder and secured in that position. This includes disc caliper pistons -perhaps even more so.
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[buzzy bee]