D2 brake question

[Tins]

My d2 has, ever since I've had it, needed a quick pump on the brake pedal to bring the pedal up to get firm braking. It stops without this, but it feels 'off'. When a local indie did the head gasket I mentioned this, and he said it was normal, and his own car did it.
It's not air. it feels like excessive disk brake runout, and I can't see it being "normal". I'd forgotten about it as the car has been off the road for years, but now it's time to get it roadworthy and I don't see it passing the check.
My feeling is the wheel bearings are worn on the front, causing runout, but what does the brain's trust think? I believe that the wheel bearings are serviced as an assembly, and are of course not cheap. Car has done 310,000. Who knows if the PO changed them?

[Bohica]

Mine was similar. I replaced the brake hoses with stainless steel braided, Teflon lined ones.

[Tins]

Mine was similar. I replaced the brake hoses with stainless steel braided, Teflon lined ones.

Did it work?

[Bohica]

Yes, much better. Drop by if you are in the vicinity and have a drive.

[Tins]

Yes, much better. Drop by if you are in the vicinity and have a drive.

Lol, I was down that way yesterday...

[Pedro_The_Swift]

I think the soft pedal is normal, they do stop better than the D1's that had a brick wall for a pedal.

[trout1105]

How much "Meat" is left on your brake pads front and rear?

[PhilipA]

FMine doesn’t do that.
I pressure bleed and flush old fluid about every 2 years and exercise the hill descent every couple of months.
I have some stainless hoses on order and have hopefully arrived when I get home next week, but even with 18 year old lines it is fine.
I have new front discs, and front bearings but if the. Bearings are crook you will get ABS three amigos.
My pads ar e also TRW so are soft and have plenty of meat.
regards PhilipA

[thai_tiger]

Had the same problem with my TD5 and found that when i did the de EGR'd it created the brake pedal double pump low pedal issue. I blanked the main vacuum line at the take off, instead of at the solenoid, which corrected it

[onebob]

D2 brakes are like that.... braided brake lines, regular fluid changes, manual bleed and then finish off with the workshop power bleed procedure, plus the absolute best quality disc pads that you can afford, and these will all contribute to diminish the problem to a point that you will be almost no longer aware of it [emoji1417]

[lewy]

mine has this.been thinking that it is vacuum related,The first pump the pedal is fine although it feels spongy, The second hardens up a tad because there is not enough vacuum which you compensate for by pressing the pedal harder hence the feeling of a better brake pedal.

[thai_tiger]

Would be interesting to know if it characteristic of both Td5 and V8 engine or is to do with the plumbing on the diesel air pump.

[Tins]

How much "Meat" is left on your brake pads front and rear?

Dunno, it's been six years since I looked. But IIRC they weren't old. Doing the pads and rotors probably tomorrow, when I'm going to follow up on the suggestion that the sliders on the calipers may be seized. Some anecdotal evidence this may be the culprit.

[onebob]

mine has this.been thinking that it is vacuum related,The first pump the pedal is fine although it feels spongy, The second hardens up a tad because there is not enough vacuum which you compensate for by pressing the pedal harder hence the feeling of a better brake pedal.

X2 that - I have a 99 Discovery II Td5 and when my alternator died the replacement was an OEM part that came complete with a new vacuum pump, however when installed there was no change in brake pedal feel compared to the old pump. As is done when ”troubleshooting” brake issues my master cylinder and brake booster pass all the diagnosis tests.
Perhaps vacuum and it’s effect on brake booster performance is dependent on engine RPM because my pedal height and feel has always better at above 2000rpm like when highway cruising but softer and lower in stop start city traffic. I have been meaning to hook a vacuum gauge in vacuum line at the EGR solenoid tee to test but haven’t got around to it yet.

[rick130]

I really do think it's a bleed issue.
My pedal isn't a rock like a Defender, but it's nice and consistent.

Bled the system old school race car style, opened the bleeds at the calipers and just pumped litres of fluid through, no pump and hold, then just for ****s and giggles did a Nanocom power bleed, no difference in pedal feel, then a modulator bleed, then a corner test.

If i think it ever feels a little soft I run a mod bleed and a corner test.

And as a few above have said, a good hit of HDC or go for a blast down a dirt road and hammer the middle/left pedal.

[ADMIRAL]

FMine doesn’t do that.
I pressure bleed and flush old fluid about every 2 years and exercise the hill descent every couple of months.
I have some stainless hoses on order and have hopefully arrived when I get home next week, but even with 18 year old lines it is fine.
I have new front discs, and front bearings but if the. Bearings are crook you will get ABS three amigos.
My pads ar e also TRW so are soft and have plenty of meat.
regards PhilipA

I agree. If the bearings had play or the discs had excessive runout, you would know about it from the shake rattle and roll at the front end. If there is pulsing on braking, look at runout on the rotors ( or bearings ) If there is vibration from the from end through the steering check the bearings.( & balljoints tie rods ) Check the slides as suggested. Also have a look at your pads. If you have gone for a high metal hard pad, the braking can be a lot slower or harder on the pedal until they heat up. Some of the newer ceramic based pads can also have this characteristic. A point on bleeding. Don't be too aggressive in pumping the pedal. Nice slow even pushing. If you stab at the pedal, you can introduce air on aged setups.