Front brake bent backplate?

[mattinhertford]

Hi all,

I've just put new cyclinders, pipe bridge and drums on the front of Monty. On the drivers side the drum doesn't spin freely even when the adjusting screws are fully turned anti clockwise so the pads should be no where near the drum. It is only on every half turn it gets stuck, but it really gets properly stuck if you know what I mean.

Photos below, something looks out of alignment between the backplate and the drum (looking at the gap on the left compared to the gap on the right) which would mean the pads are sitting squarly against the drum.

[frame][/frame][frame][/frame]

One thing i haven't done yet is to apply a hard push to the brake pedal to align the pads in the drum but it seems way off at the moment (if it can get so stuck) so I was thinking the problem was more than that, especially bearing in mind the uneven gap in the photo above.

Any advice pls?

Thanks

[mattinhertford]

Also......on the 2nd photo, the central square(ish) plate that the drum fixes to could be a little bent, its hard to tell...but if it was then that would cause the drum to sit off centre to the pads/back plate wouldn't it?

What is the name of that centre plate? Can't see it on the Charles Ware parts pages (i.e. if i needed a new one).

Ta

[LUR759H]

hi im not quite in the same situation yet, however i have just spent £20 odd pounds on new copper brake pipes on ebay also a few 2nd hand drums, shoes and bits and bobs with the intention of using the old brakes again, however ive been advised not to by a few people now and ive been told they will not stop me!! what do you think?

Alan
1969 unfinished trav

[bmcecosse]

To answer the thread... it looks to me (but not easy from a single picture...) that the backplate is square enough and that possibly the axle stub is not square? Or - it could be the hub is bent/damaged - if you rotate the brake drum - does it 'wobble' as it goes round?? If no wobble -then is it possible you distorted the backplate when working on the brakes? If all else looks ok and a straight edge across the backplate shows it is bent/distorted - then just tap the backplate back into place - probably need a fairly heavy hammer and protect it all with a lump of wood.... the 'plate' you ask about is the HUB... Again - check it with a straight edge...
To answer the second part - 'copper' is NOT suitable for brake piping - you must use Kunifer(cunifer) or good old Bundy tubing. Of course the brakes will stop you! Even the early 7" drums will lock the wheels when in good condition - what more do you want? They just won't do it over and over again in quick succession...are you planning Rally driving - or Track time? Obviously the later 8" front drums are bigger and better - fitted when the engine was uprated to 48 bhp -and these are well worth upgrading the early 7" brakes to this size - but it's not essential if the car is just a 'run around'.

[alexmcguffie]

Measuring the angles between lines 1,2,3 and 4 on your photo, it looks to me like the drum isn't seated correctly on the hub. Lines 1,2 and 4 are parallel but line 3 is about 1.5 degrees out. This suggests your backplate, halfshaft and hub are all ok but something is interfereing with the fit between the hub and drum. Pull the drum off and give it a good check over.[frame][/frame]

[bmcecosse]

I agree - and if so it will 'wobble' when rotated..

[mattinhertford]

Thanks Alex, Bmcecosse....i'll check it all out again this weekend and see if i can't solve the mystery. The drums are brand new so they should be perfect, but will check. From memory, the old drums had the same problem though so i think it must be one of the other parts. Will let you know.

Matt

[bmcecosse]

Could be failed/incorrectly fitted bearings in the hub.......

[mike.perry]

Tighten the drum on to the hub using the wheel nuts diagonally, the cross head bolts are only to retain the drums. Shoes not pads except on disc brakes

[alexmcguffie]

Mike, you shouldn't need to 'jack' the drum on with the wheel nuts. It'll make getting it off fun in the future!

[mike.perry]

No force required, just spin the wheel nuts on and tweak them up tight to make sure that the drum is on square

[alexmcguffie]

Unless there is something physically interfering with the drum/hub fit then you'll make things worse. First check is take the drum off and put it on the wring way around, outer face against the hub. That'll prove the studs aren't tight in the drum.

[mattinhertford]

All sorted, on careful measurement, one of the....now, how to describe this??....one of the hub corners that the bolt goes through (know what i mean?!?), well, one of them was about 2mm more forward than the rest, so the drum rocked a bit, hence the mis alignment. Tried to bend it back a bit but too thick so filed it down just a fraction and now the drum sits square.

Next question though....ref brake adjustment and bleeding. I read another excellent post, and the manual, that detailed it very well, but there is one small bit i'm not fully clear on. When you're first adjusting the screws, and you turn them to full lock, then back one click......at this point, how freely should the wheel spin a) totally free so that if you spin it then it will keep going for a good few turns by momentum?...or b) fairly freely but there is some light rubbing against the shoes so it stops fairly quickly, but with a single hand you can turn it again?

Reason i ask is because i had to turn the screws two clicks to get (a).......but when i try the brakes you have to push the pedal all but to the floor to get a hard stop on the wheels. My son did the pedal bit and it was fine because i could not turn the wheel at all, so good brake pressure.......but wondered if the pedal being almost to the floor is too far for that to happen, and that it should happen earlier in the pedal movement....which would mean i need to re-adjust the screws to that 'one' click as per the manual.

Make sense?

[bmcecosse]

I don't like the sound of that 'filing down'....that definitely should NOT have been necessary.... I won't be surprised if the brakes now 'grab' and vibrate..... With one click back there will still be some light rubbing - which is fine. Two clicks is too much - and yes will give you an incredibly 'long' pedal. With it all together and the wheel fitted - if you spin it - does the wheel run true with NO wobble?

[martin418]

i would recommend renewing the brake shoes as the ones in the picture are very unevenly worn , the top shoe looks less than 1/2 the thickness of the bottom and its worn more at the adjuster end , i would have thought trying to adjust out uneven wear is not helping the pedal travel nor will it do the new drums any good

[mattinhertford]

I don't like the sound of that 'filing down'....that definitely should NOT have been necessary.... I won't be surprised if the brakes now 'grab' and vibrate..... With one click back there will still be some light rubbing - which is fine. Two clicks is too much - and yes will give you an incredibly 'long' pedal. With it all together and the wheel fitted - if you spin it - does the wheel run true with NO wobble?

Ok, will watch out for that grab/vibrate on road testing. But will adjust back to one click first. Thanks bmc.