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Rear drum brake binding after front disc conversion


xychix

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18 minutes ago, Gazzar said:

One cm. Bugger. I may have to re think the use of standard rims. I will try a spacer first, then go down the wolf route, I suppose.

Thank you for testing this for me. I appreciate it.

G.

If you're so persistent on sticking with the standard rims I'll make you some photo's later today. It sure isn't a trick of angle grinding a tiny bit off. You might make it with 2 cm spacers. I'll also measure the 'thread left' on the inside of the rim at the point where it touches.

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I've now bled my brakes with the new defender 90 master. I have pressure to about halfway (I believe this is mainly rear) en then the front gets pressurised and the pedal is hard quite fast then. (without any vacuum).

Is it correct that these defender 90 masters fist send a certain amount to the rear drums and only then start to really operate the front? 

Al my flares (never did this before) seem to hold so far!

A spacers would have to be almost as thick as the outer hub (drive flange). Meaning the inner ring of the rim would have to be flat with the 6 bolts holding the drive flange on.
I'm afraid you'd loose more looks on that as you would on getting wolf rims...

If there is a good workshop day I might be able to make some wooden fillers to the point where I can measure the thickness of the spacer for it not to touch the caliper. At the moment it's 39c in the shade.......

Edited by xychix
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18 hours ago, xychix said:

I've now bled my brakes with the new defender 90 master. I have pressure to about halfway (I believe this is mainly rear) en then the front gets pressurised and the pedal is hard quite fast then. (without any vacuum).

Is it correct that these defender 90 masters fist send a certain amount to the rear drums and only then start to really operate the front? 



 

I doubt it.  The front brakes should always apply more braking than the rear, or you'll end up backwards in a ditch on slippery surfaces.

There are various types of Defender master.  Do you have one of the earlier chunky silver ones for front discs and rear drums, or the later thin black steel ones for discs on all corners?

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1 hour ago, Snagger said:

I doubt it.  The front brakes should always apply more braking than the rear, or you'll end up backwards in a ditch on slippery surfaces.

There are various types of Defender master.  Do you have one of the earlier chunky silver ones for front discs and rear drums, or the later thin black steel ones for discs on all corners?

The earlier one.

NRC9529 mated to the series servo without further adjustments.

 

running a pipe straight to the back (from the hole closest to servo) and running a pipe to a T-piece which splits to front wheels. (from the hole away of the servo)  

Edited by xychix
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I have several Series Rims here you can try to see if the fit - and several rims I know will clear the ZEUS as I have them (ZEUS) on all 4 corners.

 

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4 hours ago, Arjan said:

I have several Series Rims here you can try to see if the fit - and several rims I know will clear the ZEUS as I have them (ZEUS) on all 4 corners.

  

In that case we must have difference series rims ;) .  my old rims didn't fit with the calipers at all...
I'm happy running wolves.

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3 hours ago, Gazzar said:

Leave it for now? When I'm building up axles I'll report how I get on. Over on the slow lightweight thread.

Merci.  

 

G.

for sure! 

If i end up with non binding brakes that pass the french MOT (CT) I'm just fine.

If it's cold, I'll grab the Hilux

If it's hot, I'll grab the Hilux

If it's far, I'll grab the Hilux

If it's heavy, I'll grab the Hilux

If it's important, I'll grab the Hilux

If I want to relax and enjoy, I'll take the 109 (I think)

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got the battery back in and wired my up28 vacuum. Brake pressure now feels nice, can still push it to the bottom on the first round but there's likely some air left as I did a quick bleed on my own.

Hopefully I'll have front wheels back on tomorrow so I can lift one rear wheel to check binding after braking.

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2 hours ago, Arjan said:

Sounds good - perhaps HerLadyship can help with the brakes ?

 

haha yeah she can, I've got a proper bleed kit only thing is to close the drain at the right moment (or pump the brakes).
We'll get that sorted. Even is the misses is doing her own stuff there's 2 little princesses around here that love to help!

Decided to NOT go and do all electrics and also save the master / slave clutch cilinders for later. We need to drive! The rest can wait. Get my 5 year mot next year and then the next wave of improvements.

Did do some repairs on the electrical lines and pulled some hard shell hoses over the loom as parts of it where really crappy road side hacks...

Edited by xychix
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YEAH it drives, it doesn't bind and it brakes HARD in 2 strokes on the pedal. 
I guess with some more bleeding and adjusting rear brake shoes it should stop in 1 stroke.

alterations away from original (regarding brakes):

- seperated front and rear circuit (no faulty sensor  in between)
NRC9529 in stead of 109 master (no adapter plates)
- zeus front disc kit

- hella UP28 vacuum pump and tied open the butterfly valve in air intake (pump is from breakers, some volvo.. believe XC70)

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Just drove ~5 ish km's and the brakes stayed at a nice 34 Celcius (*about the environment temperature at the moment).

Problem is I need 1,5 strokes to get proper brakes, once its proper it is more than adequate due to the front disks doing their job.

If I clamp the rear hose I get a solid pedal on ~0.5 stroke as it should be.
Did do proper 2 man bleeding on both ends closing the nipple while under pressure.
Either there's still some air in the lines or at another point where is't hard to get out.

Will check what MOT demands are here, if 2 strokes is allowed I'll get it trough my 5 year MOT first before messing with stuff.
Good thing is it doesn't run warm anymore so I can start driving again, which is better for moral and for the car.

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4 hours ago, Red90 said:

That normally means the drums are not adjusted properly.

I set all blocks against the drum (until I could hear mild grinding) and set them back a little. 2 adjusters per side.

I'll set all the bocks agains the drums to see if that takes up the slack. If so I'll set them a tiny tiny tad back and it should be done.

 

Edited by xychix
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12 hours ago, Red90 said:

Make sure the shoes are on the right way.  It is easy to get them mixed up and then the adjusters do not work properly.

http://alre.club/Forum/index.php?topic=1253.msg8344#msg8344

The other possible problem is the pads backing off.  That can happen with warped discs, or loose hub bearings.

They've not be n off over the last years. only thing that MIGHT have happened is that the drums from the front ended up on the back as I treated them all as equal.

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It sounds like the adjusters are backed off too much.  Pump the pedal each time you make an adjustment to reseat the shoe, and set each shoe so that it is just scuffing the drum with the brakes off - any further out results in a soft pedal, and remember that when driving, the drum will be warm and expands.

I checked my plumbing and the overall configuration for Defender/Discovery 4x disc brakes is no cross-over; the port nearest the servo is for the rear brakes and the port furthest from the driver for the front brakes.  I suspect the mixed system you have is the same, a fat low pressure piston near the servo that has mechanical advantage over a smaller diameter  piston for the front brakes.  Having it orientated the other way wouldn't work as well and would need a more powerful servo, so seems unlikely.

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Think I found it. 

One of the adusters would turn round and round without setting the pad.
After removal of the drum it appears that if the blocks 'lean' outside the aren't touched by the adjusters... Could that be the issue? Is there a way to ensure pads stay in place (or is that what the drum would / should do?)

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image.png.12b6de1bd000555d69676c6dfa4aee34.png
source: http://alre.club/Forum/index.php?topic=1253.msg8344#msg8344

shows that:
1: the springs run BEHIND the shoes and note on the outside of the shoes?
2: the top holes are used, my top spring is in the wider holes just below those..

I'll try and build it according to this...

Does anyone have a more detailed breakdown of the rear brakes?
There is a little pin (almost looks like a cut of nail to me) on both sides in between the cylinder and the pads..... 


Digging more: it appears my front left pad is mounted on the front right... *(and hopefully the other way around or someone really messed up the parts on this one) 

New lesson learned: these 'tabs' that lean against the wheel thet sets the blocks to the drum can be hit out with a hammer and set back in from the other side (the side with the ring seems a tad shorter and thereby more prone to missing the wheel that sets the block.

Fiddling now for a bit and getting the last spring hook in from behind the pad seems a nightmare!! ah and the start was easy because I had the lower spring mounted a hole lower... with the lower spring in the correct holes I can't get even both bottom ends on..... 

Edited by xychix
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36 minutes ago, Gazzar said:

I assemble off the cylinder and lever on.

Levers are friends.

 

That also means you take the complete hub off, lever it al on the bench and place it as 1 unit (cylinder + springs + shoes) and therafter put the hub back. Correct?
Is I'd go down that road I'd work with all new parts ass these have likely been on there for a long long time.

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