DEFENDER2.NET - View topic - Spongy brakes when engine running

↓ Advertise on Defender2 ↓

Home · FAQ · New Posts · My Posts · PMs · Search · Members · Map · Calendar · Profile · Donate · Register · Log In

Home > Technical > Spongy brakes when engine running

Page 1 of 1

Print this entire topic ·

souster4

Member Since: 11 May 2014
Location: West midlands
Posts: 153

Spongy brakes when engine running

Hi there
Im in need of your help 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.
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, 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 hit the floor.

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

9th Dec 2014 11:36pm

jimbob7

Member Since: 06 Jul 2013
Location: uk
Posts: 2055

Master cylinder seals,get some one to press the pedal whilst you look for fluid re-circulating thru the reservoir (which it shouldn't do). Pov.spec,ftw. 2006, 110,TD5.

9th Dec 2014 11:43pm

souster4

Member Since: 11 May 2014
Location: West midlands
Posts: 153

Thanks jimbob. Does the engine need to be running to test this?

10th Dec 2014 12:12am

jimbob7

Member Since: 06 Jul 2013
Location: uk
Posts: 2055

Not really,but as it seems somewhat intermittent I'm guessin your gonna have to pump the brakes a few times to recreate the spongy feel (at which point you'll see bubbles in the reservoir),also look for black bits in the reservoir another sign the seals failed.As you recently manually bled the brakes it's probably that thats killed it.If you replace the mc you'll have to bleed it before connecting the brake lines otherwise your pushin a load of air back into the system. Pov.spec,ftw. 2006, 110,TD5.

10th Dec 2014 9:11am

landy andy

Member Since: 15 Feb 2009
Location: Ware, Herts
Posts: 5741

2006 Defender 110 Td5 USW Zermatt Silver

When I fit new calipers I like to bleed as normal, then pump pistons out a bit, clamp pipe, open bleed, force pistons back in caliper to make sure no air is trapped inside the caliper.

Andy

10th Dec 2014 9:14am

souster4

Member Since: 11 May 2014
Location: West midlands
Posts: 153

Thanks a lot guys.

I'll check for bubbles in the master res then.

If it does turn out to be the master cylinder, do you think rebuilding it would be satisfactory? Or a OEM replacement?
And how do you go about bleeding the master cylinder before connecting it up?

Lastly, do you still think eazi bleed is good enough?

10th Dec 2014 10:45am

jimbob7

Member Since: 06 Jul 2013
Location: uk
Posts: 2055

Rebuilding isn't as popular as it once was,I assume once you get corrosion inside the mc there is a possibility of it tearing the new seal,price up a new un. Lucas make the abs mc so you don't need to be robbed by LR (probably).Google "bleeding MC",there are a number of different ways,do which suits you,I fitted the new mc, filled the res and slowly pumped the brakes before re-attaching the brake lines.I also use Ezibleed,but they can still be a PITA to bleed properly. Pov.spec,ftw. 2006, 110,TD5.

10th Dec 2014 11:14am

souster4

Member Since: 11 May 2014
Location: West midlands
Posts: 153

Ive ordered a master cylinder rebuild kit (couldnt afford a new one) and vented discs. Fit the caliper spacers and then should be all good

11th Dec 2014 2:14pm

munch90

Member Since: 26 Oct 2013
Location: guildford
Posts: 3558

I would be checking for play in any wheel bearings , that could give inconsistent pedal feeling

or bleed again

master cyl problems are not that common , normally find people replace the master and say its ok now , but its the rebleeding after the cyl was fitted is what fixed it , not the cyl replacement

do you get a better pedal when sitting still engine running then when been driven for a couple of miles ?

best way is pump pedal couple of times sitting still , then leave for 1 min then try again if its spongy then good chance of air still in system , if its a descent pedal then could be play in bearings

if you got play in bearings when you drive the wheel moves side to side (only slightly ) and pushes pistons away from disc and first press on pedal will feel spongy 2nd or 3rd get better

11th Dec 2014 6:47pm

jst

Member Since: 14 Jan 2008
Location: Taunton
Posts: 8096

2011 Defender 110 Puma 2.4 USW Stornoway Grey

as above, my guess would be wheel bearings assuming the poor braking comes after movement? is it poor 2st press and then improve?

if your stationary and press the pedal and its firm does it stay firm or does it ever drop on repeated presses without the vehicle moving, engine off? Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop

11th Dec 2014 7:37pm

Page 1 of 1

All times are GMT

Jump to

< Previous Topic | Next Topic >

Posting Rules

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum