Disco 2 Brake bleeding woes

Thanks for that Pawl. I'll contact him in the morning. A recommendation is reassuring! I'd never consider used hydraulics normally, but needs must!

Tim

Hi have you seen this artical about ABS Bleeding, ist from this forum and mybe just what you need to do

https://landroverforums.com/forum/d...way-power-bleed-without-programmer-box-90951/

frostythor said:

Hi have you seen this artical about ABS Bleeding, ist from this forum and mybe just what you need to do

https://landroverforums.com/forum/d...way-power-bleed-without-programmer-box-90951/

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Jumping that relay is just a kind of massage to a wodden leg cos the real power bleed activates the inlet and outlet valves to the calipers while simply powering up the pump will let the valves in theyr's normal position and just push some fluid out through the same circuit where the pedal works that's all, might seem a clever trick to those who dont really understand how that ABS modulator works but it's almost useless believe me

Thankfully I have a Hawkeye Total. When I restored the original LR cylinder (as it turned out, with its original fault!) I power bled the system until clear of air. I then bled the system again with Hawkeye and got a load more air out. I even had to repeat the Hawkeye cycle multiple times. It took 8 litres of fluid to clear, but that may be my incompetence!
With no genuine cylinders to be found, I've tried searching for used, but can't find one of those either. Mine is the later one which is rarer.
Thanks for mentioning D2Boys, Pawl, but he is away to end August.
After 2 weeks on stands, in desperation I've had to order another Britpart, hopefully from another batch!
This time I'm going to try getting the little treasure pumping fluid before installing. I've also followed the two outlet pipes back to the wing side of the modulator. I thought I might try undoing each of those in turn and doing a crude bleed before screwing them in. Is that a stupid idea?

Tim C said:

After 2 weeks on stands, in desperation I've had to order another Britpart, hopefully from another batch!

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And what if it's not from other batch? you'll keep struggling without the pump to be ruled out 100% even if you can bleed it better it can fail in no time cos the rubber in britpart bits is the worst possible. Did you miss my reply with the TRW PMN221 which seems at a decent price compared to genuine and a good brand?

Thanks Sierrafery, I did indeed try that part number, but it's P/N SJC100442 which fits the earlier chassis. My chassis is 3A822066 which needs P/N SJC000100 and that's the one I cannot find. I couldn't agree more about Britpart, but I need to use my trailer to fetch grit & cement, as I have 150 metres of sandstone to lay before it is too wet!
Presumably the pump you refer to is the ABS. When the Hawkeye has a valve open and chattering, the fluid belts out at about twice the speed, so am I safe in assuming the pump is OK?
I've done loads of brakes on earlier vehicles, but my first go with ABS etc and I'm not enjoying it!

I named the master cylinder as "pump" cos actually that's what it is IMO, as about the SJC100442/SJC000100 is just the same part with superseded part numbers as you can see it listed in the product details here https://www.lrparts.net/sjc000100-b...y-2-right-hand-drive-fits-from-1998-2004.html i wouldnt have recommended the wrong part

and at decent price too

Thanks again for that Sierrafery, I've ordered one! The price is good value for a quality make.
Yesterday, most of the suppliers I trawled, listed the two part numbers at different prices with a chassis number to split them.
Today Island 4X4 list a single "Eurospares" cylinder with both part numbers. Even the Britpart supplier wanted my chassis number. (It'll be going back!)

Just out of interest, have you stripped down the old one to see what the problem was?

It is still on the car after I tried to flush it clear. I imagine it is seeping past the seals.
I was intending to rebuild it as a spare when genuine seals become available again. (Rimmer @ £84)
At that price though, I might see if the TRW one does the trick first!
I did have a go at getting the Britpart one apart as practice, but it put up quite a fight. The yellow plastic cover came off OK, but I then met a fine circlip with no eyes or ears. No idea how you are meant to deal with that in the professional world. I tried prising it out with various blades, but as it was scrap, i drilled a hole in the side and poked it with a nail! The first piston came out easily but the next lump was more reluctant, then I lost interest! It is certainly a lot harder to change seals than it used to be!

Tim C said:

It is still on the car after I tried to flush it clear. I imagine it is seeping past the seals.
I was intending to rebuild it as a spare when genuine seals become available again. (Rimmer @ £84)
At that price though, I might see if the TRW one does the trick first!
I did have a go at getting the Britpart one apart as practice, but it put up quite a fight. The yellow plastic cover came off OK, but I then met a fine circlip with no eyes or ears. No idea how you are meant to deal with that in the professional world. I tried prising it out with various blades, but as it was scrap, i drilled a hole in the side and poked it with a nail! The first piston came out easily but the next lump was more reluctant, then I lost interest! It is certainly a lot harder to change seals than it used to be!

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The reason I asked is because many master cylinders fail through the cylinder getting rusty due to the water that brake fluid absorbs.
So you can get rid of the rust with special honing stones. Then providing there is enough "meat" on the seals, you can clean it all up, reassemble, and then it is good to go again.
Main reason for changing brake fluid of course.
Something like this.
Lots available.
https://www.lislecorp.com/specialty-tools/brake-cylinder-hone

Stanley you buying your tools from the USA now

frostythor said:

Stanley you buying your tools from the USA now

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No way José!!
Just showing wots available.
when in Frogland as I am at the mo, it isn't always easy to show what's available in Blighty!
but if he gets the idea, he'll find it closer to home!

Must be a Brexit problem if you cant get UK Google in France, is it posible they have blocked it as our stuff is better, and they cant buy it now

frostythor said:

Must be a Brexit problem if you cant get UK Google in France, is it posible they have blocked it as our stuff is better, and they cant buy it now

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No, you can get it if you make the effort, all I was trying to do was to show the OP what is available.
If you get Google uk, it quickly reverts to google fr and it's just a pain having to constantly reset.
I hope the OP got the message!

The new TRW cylinder arrived this AM from Germany! It came without reservoir, but no problem. Looks identical to the LE original. I started by cracking open the two feeds onto the modulator, using power bleed until fluid ran out. Then I bled round it twice with the Hawkeye, but very little more air came out.
I now have a good hard pedal with engine off. However start the engine and my foot slowly sinks to the floor. as before. Release the pedal and it immediately goes hard before sinking again. (This is not just the usual initial dip on start up). On the road, a jab on the brakes will sometimes engage the ABS, but brakes aren't sharp enough. It really doesn't behave like air as you can get a hard pedal just by releasing it, without pumping. It is definitely not right as you couldn't hold it on a hill with the engine running.
Could it be a leaky modulator valve? To me it doesn't sound like servo, but I'd like to try releasing the air hose from the servo and see if it makes any difference. Does the rubber plug twist and pull? Rave just says remove it without saying how!

Tim C said:

I started by cracking open the two feeds onto the modulator, using power bleed until fluid ran out. Then I bled round it twice with the Hawkeye, but very little more air came out.

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Why? As i understand you filled the modulator with air to power bleed it after and you didnt pedal bleed it too? IMO the problem is that you are doing things the wrong way.... if there is air in the pedal's circuit through de modulator the power bleed has no effect on it nor the pedal on the air in the active braking circuit. Once the modulator got air you have to power bleed it while you push the pedal too then pedal bleed it.

The problem of a sinking pedal with engine running was the original problem, before I changed the master cylinder. The two pipes I cracked open were on the wing side of the modulator which I think come from the master cylinder. The idea being to stop air from the new cylinder ever getting into the modulator. Afterwards the pedal was immediately hard (engine off). I then bled each wheel with Hawkeye to catch any air which might have got into the system. Surely if it was air, the pedal would be soft with engine off as well?
For elimination, I will try isolating the servo this morning by starting it with the serpentine belt removed.

Tim C said:

I then bled each wheel with Hawkeye to catch any air which might have got into the system.

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what you bleed with hawkeye goes into the lines close to the modulator and the return pump has not enough power to push it out all the way untill the caliper cos on power bleed the fluis is circulating between the Inlet and outlet valves so after each power bleed pedal bleed is compulsory... disabling the servo is useless cos it will not reveal anything as long as there's no leak cos without servo assistance the pedal has not enough pressure to open the one way valves in the modulator so the expansion chambers are bypasses hence solid pedal, it's not supposed to be a solid pedal all the way with running engine on a D2, my vehicle is braking perfectly and the pedal sinks to the floor if i insist on it and that's normal.