Brakes not right! Spongy when engine running

Hi there,

i just want to say, sorry for the several posts from myself regarding problems. Im in need of your help again - now regarding my brakes. I never seem to have much luck with land rover brakes, but i am learning. And learning from my mistakes

Ive recently done a brake overhaul on my 300tdi defender 90 1995.
Consisting of:
New pads and rear discs (mintex)
New calipers front and rear (bleed nipple at top)
New brake pipes and braided flexis
New servo (OEM)
Wheel bearings new and fine

What im finding is, the brake pedal is very inconsistant, one minute it feels quite firm, the next it feels very spongy. Considering they are all new calipers all round, and the discs and pads are bed in (3k), the braking performance i think still seems poor.
Ive tried bleeding with the eazi bleed, and manually bleed, and there isnt much difference really, the overall performance is still poor. The brakes got wet and muddy on sunday, and the pedal just seemed to push to the floor. Felt like i had sponges instead of brake pads!

I did buy front vented calipers (OEM) and split them, removed the spacers and fitted them with the seals out my old calipers to go onto my solid discs. I dont appear to have any leaks, and when the engine is off, the pedal feels hard and doesnt creep.

How should the brakes compare to a 2003 TD5 defender? Because they dont feel as good. And with all the replaced parts, i would hope they would be equal or better.

Can anyone advise me where to look next? Or should i take it to a garage and get them to bleed it properly?

Many thanks in advance

Also, to rule out the front calipers letting air in. Do you think it would be worth buying front vented discs (need new fronts anyway) and fitting the spacers between the calipers that have new seals. That way I'd know for certain the calipers are all good.

Are the rears drum brakes? I had a similar sounding issue with mine (also after a brake overhaul). Bled and bled them but pedal would change between being firm and spongy.
My local garage fixed it in the end, he said the springs in the drum were setup incorrectly and changed the brake master cylinder.

Blizzard44 said:

Are the rears drum brakes? I had a similar sounding issue with mine (also after a brake overhaul). Bled and bled them but pedal would change between being firm and spongy.
My local garage fixed it in the end, he said the springs in the drum were setup incorrectly and changed the brake master cylinder.

Click to expand...

Its discs all round mate. With new calipers.

Is rebuilding the master cylinder acceptable? Or is it best buying a replacement?

probably air in them still.

shame you got braided as you could have just clamped the rubber hoses to identify where the issue is.

go and get someone to stamp on the brakes when the engine on, pump 3 times and stamp hard and look for leaks on the rebuilt callipers. do it for each caliper and the line joints.

then eezibleed again but also do the old 2 man pump on the pedal with a helper, it can help to shift air. though you might roll a mc seal, but that's what i do anyway.

I have exactly the same symptoms on my 89 90 and replacing the master cylinder didn't seem to fix the problem for me. Mine passed the MOT like that so I'm guessing I'll just live with it until I can find the problem

trax said:

probably air in them still.

shame you got braided as you could have just clamped the rubber hoses to identify where the issue is.

go and get someone to stamp on the brakes when the engine on, pump 3 times and stamp hard and look for leaks on the rebuilt callipers. do it for each caliper and the line joints.

then eezibleed again but also do the old 2 man pump on the pedal with a helper, it can help to shift air. though you might roll a mc seal, but that's what i do anyway.

Click to expand...

Thanks Guys.

Ive bled them 3 times now, i cant possibly see how air can be still in them, unless its getting in somewhere.

Do you think air could be getting in, between the calipers halves? As i bought new ones, removed the spacers (far cheaper) to fit on the solid discs.
Im just second guessing whether the seals i re used are good enough

trax said:

probably air in them still.

shame you got braided as you could have just clamped the rubber hoses to identify where the issue is.

go and get someone to stamp on the brakes when the engine on, pump 3 times and stamp hard and look for leaks on the rebuilt callipers. do it for each caliper and the line joints.

then eezibleed again but also do the old 2 man pump on the pedal with a helper, it can help to shift air. though you might roll a mc seal, but that's what i do anyway.

Click to expand...

Exactly as described above

If the pedal is remaining hard when the engine is off... Wouldnt that show there is no leaks?

I cant see how there is still air in them after theyve been bled 3 times. Twice with the eazi bleed, once manually.

The only thing could be that air is getting in somewhere!

Can the pedal be pumped while the eazi bleed is connected?

ONE LIFE LIVE IT. D90 said:

If the pedal is remaining hard when the engine is off... Wouldnt that show there is no leaks?

I cant see how there is still air in them after theyve been bled 3 times. Twice with the eazi bleed, once manually.

The only thing could be that air is getting in somewhere!

Can the pedal be pumped while the eazi bleed is connected?

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Because it sounds like you have a small leak. Where about's are you.?!

Landyfox said:

Because it sounds like you have a small leak. Where about's are you.?!

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Im West Midlands - wolverhampton. I'll have to double check all the unions and calipers then.

I think im going to put the spacers spacers back in the calipers and fit vented discs. That way i know 100% its not the calipers

ONE LIFE LIVE IT. D90 said:

Im West Midlands - wolverhampton. I'll have to double check all the unions and calipers then.

I think im going to put the spacers spacers back in the calipers and fit vented discs. That way i know 100% its not the calipers

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Ah if you had've been closer I would give you a hand. Start at the beginning, it's just a process of elimination. Try and note what appears to temporarily improve it and trace it back. If you can, get a friend to give you a hand.

Landyfox said:

Ah if you had've been closer I would give you a hand. Start at the beginning, it's just a process of elimination. Try and note what appears to temporarily improve it and trace it back. If you can, get a friend to give you a hand.

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Thanks Landyfox.

Ive done so much work on them, and they are miles better than when i bought it, but they still just dont seem right.

Should they be as good as a 2003 TD5? With all the new calipers, new lines and new servo?

ONE LIFE LIVE IT. D90 said:

If the pedal is remaining hard when the engine is off... Wouldnt that show there is no leaks?

I cant see how there is still air in them after theyve been bled 3 times. Twice with the eazi bleed, once manually.

The only thing could be that air is getting in somewhere!

Can the pedal be pumped while the eazi bleed is connected?

Click to expand...

system isnt under full pressure with engine of id fit a new master cylinder and adjust rod or try blocking pipe to each caliper in turn ,bleeding and trying with engine running

jamesmartin said:

system isnt under full pressure with engine of id fit a new master cylinder and adjust rod or try blocking pipe to each caliper in turn ,bleeding and trying with engine running

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Thanks James. Do you mean trying to bleed with the engine running?

And is it worth rebuilding the master cylinder? I'll bleed the master before connecting the pipes though.

Then use eazi bleed?

running engine shouldnt be needed to bleed if it is theres a problem, you could try rebuilding master ,but it sounds like there still or is getting air in or stroke of pistons is too much or wheel bearing /poor disc issue ie pushing 1 or more caliper pistons back thus creating greater travel

jamesmartin said:

running engine shouldnt be needed to bleed if it is theres a problem, you could try rebuilding master ,but it sounds like there still or is getting air in or stroke of pistons is too much or wheel bearing /poor disc issue ie pushing 1 or more caliper pistons back thus creating greater travel

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Do you think it would be a good idea to rebuild master, re insert caliper spacers to ensure they are totally new. Check all unions over for any leaks as other suggest. And give them a damn good bleed?

if you are going to go down the mc route, just try pumping the brakes when using the eezibleed first. cheap and easy

trapped air can be a bugger and you have changed a lot.

trax said:

if you are going to go down the mc route, just try pumping the brakes when using the eezibleed first. cheap and easy

trapped air can be a bugger and you have changed a lot.

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Cheers Trax. Will the MC seals be okay with pumping while the eezi bleed is connected?