Rear Brakes Binding

[Pettifordo]

After a year of welding and rebuilding I’m starting to move the car under power up and down my drive.

The rear brakes are binding especially on the passenger side.

The brakes shoes are new as is the handbrake cable and fixings plus the brake cylinder.

I adjusted them by getting them to the point where the wheel didn’t turn and then eased it off until it turned.

Does that sound right ?

Any tips on how to adjust them different or other causes of the binding (I’m not 100% sure I got the handbrake set up right 😩😩)

[Pettifordo]

Just thinking about the rebuild process, it is possible that I have put the drums on the opposite wheels - when I refurb that part I took  both sides to pieces at the same time so these could have got swapped - could 42 years of wear made them “sided”…..not sure how I could tell

[johny]

Do they bind continually as you rotate the wheel or just intermittently each revolution? Side shouldnt make a difference...

[dougbgt6]

You can also get the shoes upside down which isn't good. 

Doug

[Pettifordo]

4 minutes ago, dougbgt6 said:

shoes upside down which isn't good.

How can I tell if they are on wrong ?

[Pettifordo]

16 minutes ago, johny said:

bind continually as you rotate the wheel

I’m going to strip them down tomorrow and see exactly where they are binding - can just feel the pull as you drop the clutch and going backwards the os wheel spins in the gavel because the ns os binding.

Hopefully a strip and rebuild will sort them.

[johny]

Compare the set up you have with the manual cos as Doug says easy to get wrong!

My drums went oval so would bind periodically each revolution - I could have just wound off the adjuster and had more pedal movement but I got them skimmed round as Vitesse/GT6 are quite expensive but probably not worth it on Spit/Herald as the drums are cheaper new...

[NonMember]

Also remember that the handbrake linkage geometry changes with suspension movement, so you really need to adjust it with the car resting on the wheels (which is obviously impossible) or at least with the weight taken under the vertical links, not the chassis.

[Pete Lewis]

a few basic clues on brake settings

jack up and support the axleunder the upright   to be close to its on road height  so its not left hanging 

remove wheel to helpaccess to the cable clevis pins 

remove one side from the wheel cyl HB lever 

remove drum and check the rear shoe has the square hole unused handbrake fitting  is at the bottom   ( opposite to the front shoe which must have the hole at the top)

thats sorts out if you have a shoe upside down

fit drum and screw adjuster fully up hard  

reconnect the cable and adjust to make the clevis a nice fit  no cable tension 

when done de adjust the adjuster to free the wheel  ( around 4 clicks   one full turn)   not easy to acces but best done with wheel on 

make sure the drum retaining screws are flush and cannot foul up on the wheel as this will distort the drum

hope that a help

Pete

 

[dougbgt6]

Even with the manual I find it difficult to tell if I've got them in right, also the springs top and bottom, are they right? And which holes do they anchor in again?!!  Look at the manual VERY carefully.

Doug

[Josef]

11 hours ago, Pettifordo said:

How can I tell if they are on wrong ?

The shoes have a square hole in one end which the handbrake lever fits through. The other shoe (that doesn’t engage with the handbrake mechanism) should have that square hole facing downwards. 

[DerekS]

As an aside,a few years ago I bought a new set of quality shoes and, try as I might, just could not get the drums back on either side. It turned out that the linings were bonded on in the wrong position,  further round the shoe than the should have been by about half an inch. Shouldn't have made much difference I know but it did, the replacements flew on.

Derek.

[Colin Lindsay]

How far have they been driven since fitting? They'll need to bed in, particularly the versions that are square on the ends of the linings, not chamfered. Once this wears away the shoes are much more amenable to adjustment. You can accelerate the process by smoothing down the edges of each shoe lining to a smoother angle; otherwise when you initially set the shoe adjustment, this edge is the first thing that will make contact and being out of profile with the curve of the rest of the shoe can prevent accurate adjustment. Just a thought!

[Pete Lewis]

to aid access to the square adjuster with a wheel fitted buy a cheap 1/4" drive extenion and thats a good fit on the square  you can turn it with a spanner or find a socket to fit the male end 

Pete

[DVD3500]

I fixed this recently on a friend's 1500: Had to replace the adjuster and somehow the rear brake cylinder stood proud so we used a C clamp to push it in. Went on like a breeze...

[Pete Lewis]

just to add one other demon in rear brakes is   the back plate can wear from the hand brake lever pivots make a groove in the backplate

this stops the free slide action of the wheel cylinder .

you  need to remove the cyl to see this , the only cure is weld up the wear groove and disc off to  make  it  smooth again 

Pete

[Colin Lindsay]

57 minutes ago, Pete Lewis said:

you  need to remove the cyl to see this , the only cure is weld up and disc off the make smooth again 

Pete

Your 'Pete to English' translation app is playing up again.

[Pete Lewis]

i only do it to practice  editing   Ha !

Pete

[Pettifordo]

So I stripped the brakes down and all looked ok, except on the lower spring on the binding side wasn’t on the furthers hole (which could have meant it was sticking.

This was the non-binding side

 

This was the binding side

What I did “find” was that the spring that returns the handbrake lever didn’t have much tension on it so I adjusted that so it looks like this now 

Handbrake off

Handbrake on

This has improved the feel of the handbrake and the lever is returning well.

I then looked at the drums (which I never gave too much attention when I was rebuilding the suspension) and the binding side had some “crud” on the inside so I got both drums and cleaned them up.

The binding side still has some pitting and score marks - I should probably get new ones

Anyway all back together and I will plan a test drive later - after part 5 of my windscreen fitting saga.

My secret weapons for success this time are KY Jelly and a Smoother Rope - wish me luck !

[johny]

I think youre ok with that drum if its not oval - remember any pattern replacement you get might give further problems....

Set up looks good except you have two nuts on one side of the spring to cable attachment and the outer one of these should be up against the drum operating clevis to clamp it rigidly on the cable. Also the clevis should really be attached to the drum lever with a pin which is then secured by a split pin. Using a bolt as you have might allow some play and of course could come undone so dont know what an observant MOT tester might make of it.

[Pete Lewis]

if you have to use a bolt it needs a shank to contact the wear points and always fit a bolt so if the nyloc/nut lets go the bolt wont drop out 

but agree clevis and R clip or split pin is the std  fit 

having said that it a lot easier to remove a nut than a rusty siezed spit pin 

Pete

[Pettifordo]

1 hour ago, johny said:

drum operating clevis

I wondered why I had so many nuts ! The bolts have Nyloc nuts on them.

[Colin Lindsay]

Any witness marks on the shoes to show where they might be hitting more than other areas?

[Pete Lewis]

always make sure the drum and hub faces are really clean and burr free

if the hub has been removed a few times over the years its worth having them skimmed as any face distortion magnify drum run out

 

Pete

[dougbgt6]

Is it me or do those shoes not look right? The brake material is in the wrong place they almost look symmetrical, they shouldn't.

 

 

Doug