Series 3 109 Rear Brakes - Snail Cams

I'm reassembling my rear brakes (11" SLS) and find that the web of the shoe fouls the snail cam. I took the snail cams off when I had the backplates galvanised and I have a dreadful feeling that I have reassembled them incorrectly.

In my current setup, working from the inside out, I have the adjuster bolt/backplate/heavy spring/washer/snail cam. I have a feeling looking at it all now that the spring should be on the other side of the backplate, ie between the adjuster bolt and the backplate.

Can anyone with these brakes still in factory format please tell me if this is correct?

Yes the springs on mine are on the outside.

Just a thought....on a 110 the shoes are handed, are they on a 109? And if they are..are you aware?

Thanks for the prompt replies guys. The shoes on the 109 are handed in that there is one leading and one trailing shoe per side. Got that bit sorted. Don't think there is a difference LH vs RH as far as I can see. Either way they wouldn't fit, being incorrect by the thickness of the adjuster spring. Mine's an 88" with 109" rear brakes and a limiter. Don't know why. Need to find/ask previous owner! Ha ha.

I've carefully ground the snail cams off the bolts (for the second time now! Should've taken a photo of this bit during disassembly!) Put them back with the springs on the outside of the backplate. Quick blast with the MIG. Now it all fits a treat.

Cheers
Andrew

Has the previous owner fitted the complete 109 Salisbury axle perchance? It's stronger than the correct rover axle.

No - she has got an ENV rear axle and a Military Spec Rover one up front. So it's a right mish mash really. The 11" brakes may have come with the ENV rear axle, or might be a later addition. I'm not sure if the ENV rear axles ever came with the 10" brakes as standard. That axle may be off a forward control 2B. I'm not sure what brakes they came with.

So when I bought her, she had 10" SLS brakes on the front and 11" SLS on the rear. I'm replacing the fronts with Heystee discs and I considered putting the 10" set that were on the front onto the back, but I stuck with the 11" and a limiter to stop them locking prematurely.

All good fun!

Cheers
Andrew

So - I've done one side. Now I go to the other side and I'm looking at the snail cams and wondering if they are pointing the correct way.

Found this photo on the web. Supposedly a pair of backplates.

This seems to show the snails pointing the same way, despite the backplates being handed LH and RH. Surely on a handed pair, one lot of snails will point one way, and the others will be opposite? Or am I missing something?

Incidentally - I know the upper spring is incorrectly mounted in this shot - it is supposed to be between the shoe and the backplate.

Elsewhere on this forum, there are instructions saying make sure all the snails face the front of the car. If on both sides the snails are supposed to face the front (and the tails facing the back) then this photo above must be of two identical sides.

Can anyone shed any light on this for me? I've done various searches for pictures of a pair of bare backplates, but not had any joy.

Cheers
Andrew

But now I've had another search and found these photos. (Thanks John Richards Surplus!) The two part numbers are 531889 (RHS) and 531888 (LHS).

Firstly 531888 (LHS - So passenger side in UK and here in NZ). Looking from outside inwards. Front of car is to left of picture.


Note snail cams pointing to front of car. (Assuming the head of the snail is at the fat end of the cam!!)

Now 531889 (RHS - Driver's side) Front of car is to right of picture.


Snail cams are identical, so now they are pointing to the rear!

You can tell the photos are of the correct backplates, as the six big mounting holes in the middle are on a different orientation in each shot.

So - this appears to tell me that indeed, the cams should all be in the same orientation, but the ones on the driver's side will point backwards, and the ones on the passenger side will point forwards. This at least does make sense when you look at the previous photo showing the two backplates together.

Cheers
Andrew

The snail cams should be arranged such that a clockwise rotation of the adjuster moves the shoe closer to the drum. The top spring is shown correctly located, it should be shoe to shoe not shoe to backplate.

Mine are arranged the same as the pictures you have included, I put the top springs behind the shoes.

Yep - That's all making quite a bit more sense now.
Looking back at the thread, I should have said the springs are supposed to be located on the backplate side of the shoe, exactly as shown in Citizen Kane's photos, and not as shown in my photo. I believe the correct spring mounting has the effect of pulling the shoes over towards the backplate slightly, instead of outwards towards the wheel, where they might foul the inside face of the drum.
Thanks for everyone's advice.

Cheers
Andrew

Agreed, the springs pull the shoes against the back plate, pity many pictures show them wrong!

Don't those brakes also have the adjusters from the back plate too the shoes to keep them square to the drum?

The only adjusters on these brakes are the snail cams. See photos of the bare backplates above. There's nothing else there to adjust!

Will see if it all works when I get the rest of the car back together......

The snail cams are a pain, they move the shoes a lot for each click so a small error makes a big differnce to the pedal. You can't ajust until the wheel is on as the wheel nuts hold the bake drum square. Fully anti-clock until you feel the stop, then drum and wheel, then closckwise unitl the wheel becomes stiff, then what it a few times and stamp on the brakes and try it again. Should be backed of one click from rubbing, sounds easy but its not.