bleeding brakes - spongy pedal

Sorry it's another bleeding brakes thread! I have read some of the others but I've still got a couple of questions.

Series 2A, no servo, shared 'bean can' reservoir. I've fit all new brake pipes and new master and wheel cylinders. I had a couple of obvious leaks at the start but after nipping them up I'm no longer losing any fluid from the reservoir or finding any on the garage floor so I don't _think_ I have any leaks.. and I've bled through almost 2 litres of fluid in my attempts since nipping those leaks up. I've also checked behind the drums and the new wheel cylinders are bone dry no leaks in there.

FIRST ATTEMPT I used a Halfords one-man bleed kit, the sort with a non-return valve in the tube going into the canister. It worked well enough but after bleeding all round 3 or 4 times when I pushed the brake pedal down it just about hit the floor the first time before firming up on the next stroke.

I thought maybe I was sucking air past the bleed nipple threads (despite having some PTFE on each one) as the pedal was coming up while I pumped with the one-man kit, so SECOND ATTEMPT bought a pressure bleeder from Paddock. This would have worked well if I could get a decent seal on my old bean can reservoir. As it is, I connect to a tyre and brake fluid slowly spills out from under the cap on the reservoir. I did persevere but it's not ideal like it might be on a Series 3 with the separate plastic reservoirs that would seal properly. New bean can reservoirs are £100 .. ! :O

THIRD ATTEMPT.. old school! Got the wife out and taught her to push down while I was saying DOOOWN and opening the thread, then I nipped it up before saying UP. Did this half a dozen times on each cylinder, no bubbles coming out at all, went round twice. Still no joy. First time down it just about touches the floor and firms up with a couple of taps. And I only have to leave it 3 seconds before trying again and it will touch the floor again.

QUESTIONS

Has anyone got a pressure bleeder to seal right on an older bean can reservoir? Any tricks or tips?

I've left it with the pedal held down with a bit of 2x4 because I've read overnight that can fix this kind of problem - but I admit I don't know why it would. What's that actually doing for me? The piston in the master cylinder will be pushed all the way in overnight - how does this remove air?

It doesn't hit the floor that first time easily, and won't at all on the second press, but my old man's telling me it shouldn't really hit the floor at all even on the first press. Is he right? He's never driven one without a brake servo on it..

Cheers!! Tad frustrating after fitting all new pipes and master and wheel cylinders. Land Rovers I love em.

Try this...
Get some (2) brake pipe clamps to clamp the flexis off.
Put 1 clamp on passenger side
Put 1 clamp on the rear T flexi
Bleed the drivers side using option 3 with the well trained wife.
You will/should get a solid brake after a few pumps.
Then when pedal solid release the passenger clamp while under brake pedal pressure.

If you still have pedal after doing the front move to the rear.

Hope this helps.

Your Dad's right.

A successfully sealed pressure bleeder works as well as a trained wife, but keeping either airtight can be a problem.

Sounds to me as though you've done as much as you can, and I was also sceptical about the jammed pedal method but it worked for me on a Fiat clutch. Might have been luck though.

What brand were your new parts? A number of us have a dread of the non oem stuff. Is the car on level ground?

I'd go with Phil's suggestion and try to isolate the problem.

Are you backing the brake ajusters all the way off first? Its imporant to do this to bottom the pistons in the cylinders so there's no where for air to sit. Are you keeping the bleed tube submemrged so it can't suck aire back?

You don't use PTFE on bleed nipples, they seal on the bevel against the sealing seat not the threads.

I'd be looking at the shoe adjusters too

As a check adjust all the shoes so they are tight against the drums, you should be able to see then if its a shoe adjustment issue i.e too much distance between shoe and drum.

Lots of useful replies as usual thanks all.

> Your Dad's right.
Yeah he usually is.

The vehicle is on level ground.

I didn't pay much attention to keeping the tube submerged on the first two attempts because it has a non-return valve in, but as I started to doubt everything, when we did it the manual way I was careful to keep it submerged.

Because the pedal firms with a couple of pumps I'm focused on finding where the air is that I'm having to squeeze rather than thinking about shoe adjustment. Is this right? I've got all the shoe adjusters backed right off, they're new shoes and new drums. My neighbour's told me yesterday to tighten them all up and then bleed it as it's what he used to do on HGVs.. but I'm not sure why and he couldn't really explain it. If I have them backed off, the pistons are back in the cylinders before we press the pedal. If I wind in the snail cam adjuster it will push the leading shoe against the drum, the piston on that side will push out of the cylinder as it follows, and pull fluid into the bore. I don't understand why I'd do one and not the other when bleeding.?

I'm going to try tightening all the adjusters and bleeding today anyway as more than one person's suggested it. If that doesn't work and the 2x4 hasn't done its magic overnight I'll order some clamps as phil suggested it sounds like a good way to narrow down where the air is.

Hi, not sure if your 2A has the CB or the CV master cylinder, but if it's the CB then according to my old Autobooks manual, it needs a special technique:
"the system must be refilled under a pressure of 14lb/sq in since the angled position of the cylinder leads to air becoming trapped at the cap end ... it may be necessary to raise the vehicle until the cylinder is horizontal and also to slacken off the outlet pipe while filling."
It sounds like the CB is tricky to bleed successfully without an Easibleed or something similar.
If you have the CV master cylinder then ignore the above!

Both new OEM CV masters but thanks for posting ExMil

Holding the pedal down overnight worked for me on an MG B, was really surprised! I read that you could also give the pipes a good tap at the same time, the theory being that it'll cause any air to float to the top. I did that, but whether it made any difference or not.....

I also couldn't get the cap to seal on the master cylinder when using the pressure bleed kit, so I wrapped some PTFE tape around the thread - that did the trick!

A combination of tightening the brake adjusters while I bleed, using some 2x4 overnight, AND getting a decent seal on the pressure bleeder by using plenty of PFTE wherever I could stick it (thanks Bern!) - has got me a pedal that won't hit the floor anymore. Pack yourselves on the back! It does still get firmer with another pump or two, but no firmer after that. Could this be called normal for a no-servo Series? As I've never actually bloody driven one yet I don't really know what I'm aiming for!

I'm still going to get some clamps anyway and see what they tell me as a sanity check. My wife needs me alive, despite the looks she gives me when I ask her to help me bleed my brakes.

Once you bled them jack a wheel up spin it press the pedal.
Then move the snail cam a few clicks so you don't have to press the pedal down to far. Do this all the way round. But make sure you don't do them to tight to cause them to bind.

Yep brakes can get better. But you still have to plan quicker if you need brakes(this keeps the brain active)

scottonthefen said:

It does still get firmer with another pump or two, but no firmer after that. Could this be called normal for a no-servo Series?

Click to expand...

no

My clamps arrived. When I fit all three the pedal was rock hard, and was still very firm with just the rear clamp removed.

On the front either clamp removed made the pedal a bit worse and with both front clamps removed the spongy pedal was back so these helped me pinpoint the air in the front cylinders.

I bled them one at a time with everything else clamped off and got nothing out. Then I tightened the adjusters right up and got air out both front sides with the pressure bleeder, so it had been hiding in there somewhere! I set my adjusters back where they should be and bled both sides once more to make sure and with all the clamps off now I've got a very good pedal, it goes down about half way and doesn't get any firmer with more pumping. That'll do for me now. Cheers all!