MY RP is fitted with a semi-girling front axle with long brake levers. To be honest I have never touched them since I got the car nearly 30 years ago, although the shoes have been re-lined and the cables replaced. However... before May of next year I am going to have to submit the old girl for a french "Contrôle Technique" and in anticipation of that and my proposed attempt at the "Col de la Bonnette" and the Cévennes Winter Rally I thought I'd give her the once over. Now the brakes are adequate but in terms of mechanical efficiency they could be better. I wondered whether the arms were on the 'wrong way round' but I'm not so sure. There definitely is some free movement at the cam (see photos) but I would have thought that when retracted the cam would be vertical and the operating arm facing forwards so that the angle between the cable and the arm was always less than 90°. However (and here's the question) When at rest, the arm is vertical too. You can see the difference when the play is taken up, so even if I swap them round they'll still be vertical at rest and pointing rearwards when fully applied.

What's wrong?

At rest:

Applied:

Apart from that, how do you get the bloody things off? There isn't enough clearance between the hub and the axle...

Location: Autumnal southern France

Hi Reckers,
I can't answer your question directly as I no longer have a semi girling axled car to look at and I can't remember but, I totally agree with your logic as regards the ideal position of the brake levers so, here are a few thoughts:

1)In the "at rest" pic are you sure that the cam faces are absolutely square to the actuator pistons?

2)The cams, AND the brake levers are handed - see the 1937 parts list here so there is lots of scope for something being not quite as it should be.

3)There is a good chance that both the shafts of the cams and the oilite bushes in which they run are worn, might be worth replacing whilst you have things in bits.

4) I think, to get the levers off you will have to remove the hub and shoes and having removed the lever cotter, remove the 2 small nuts holding the the brake actuator unit to the backplate and withdraw the unit to allow the lever and lever return spring to come off.

Ian Mc.

Location: Shropshire

My memory is that original Austin-Girling cams were actually marked, front and rear, right and left. I think the marking might be on the end you can see. Can anyone else confirm this? If so, worth a look before you remove the hubs.

Regards, Stuart

Cams for these brakes are marked N/F, N/R, O/F and O/R, each is unique.

To remove the arms you must remove the hubs and brake shoes, dissemble the cotter and tap the cam through the brake arm, I raised an idea that I had about cutting a semi circle from the hubs so that cams can be removed without disassembling the front and rear hubs on another thread but it received no comment...this is the kind of job such a mod would be very helpful.

New arms, bushes and cams are available from 7 Workshop (and others) and having just done this job I can vouch that correct assembly and replacement of worn parts made a startlingly positive effect on the cars ability to stop!

Good luck, you'll need every ounce of brake you can muster on your 'Bonnette descent.

N.b. front levers should point up and forwards (about 8 o'clock as you look at them), when 'off'.

Thanks for your comments thus far. Next stage is a strip down to see where we are regarding the cams etc. There's definitely too much movement for my liking which probably means a set of front shoes and/or some shims (I got to be quite an expert at shimming the brakes on my Yamaha trials bike)

Am I right in assuming that I need a puller to get the hubs off?

Location: Autumnal southern France

You can use the rear hub puller.

If you don't have on of these, use some tyre levers behind the hub, done this many times without any damage and the hub usually slips off easily as it is not on a taper.

Shims should not be necessary with semi Girling (as they have a top adjuster), and would be hard to make work in the confined space available, I would opt for new parts.

You can smooth the plunger faces carefully on a grindstone, or similar, if they have grooves in them.

OK Boss, will do. Got a rear puller. Will be going in at first light tomorrow.

Location: Autumnal southern France

Over and out...

How about this... (you get like this trying to avoid watching X-factor etc)

At rest the brake levers are vertical. The cotter pins are facing forwards (ie narrow part of the taper to the front. If the cotter pins are inserted the other way round (threaded part to the rear) then the taper should make the brake lever tilt rearwards, which then begs the question as to whether the arms are on the wrong hubs. Swapped over with rearward facing cotter pins they should then face forwards. Am I thinking on the right lines or am I rambling?

Time for Mr Spanner to do his stuff, methinks.

Location: Autumnal southern France

I suspect that the levers may be on the wrong sides but, received wisdom is that your cotters are correct with the nuts at the front.

Ian Mc.

Location: Shropshire

Thanks Ian. It will all come out in the wash when I strip it down tomorrow.Just one final question. If you look at the first photo showing the brake lever at rest, you can see the lower portion where the ball is, faces rearwards presumably to prevent the cable end from cutting into the lever. If I swap the levers over then both lower portions will be angled forwards and not rearwards. That sounds wrong.

Location: Autumnal southern France

Swap the cams, not the levers.

Rodger that. Early night I think. My brain hurts!

Location: Autumnal southern France

Location: Shropshire

Quick update...

Stripped down the FNS this morning. Everything came off OK without any hassles. No wear issues apart from the brake shoes which are down to the rivets (just).

I have separated the camshaft from the lever and...

it looks like the cams are not 'handed'. The seating for the pistons is (ar at least appears at first sight) to be exactly at right angles to the machining for the cotter pin which suggests that the only thing to determine the 'at rest' angle of the brake arm is the direction from which the cotter pin is inserted. There are no markings on the camshaft to indicate 'left' or 'right'.

I will get the other side taken down tonight (I have to take the Mem'Sahib's modern in to the Peugeot Garage this afternoon) and will take some more photos to show you what I mean.

Curiouser and curiouser.

Location: Autumnal southern France

Hi Reckless
I have just today completed the refurbishment of my semi Girling front end.
I was dismayed to read however that the cotter pins should be inserted from the rear. You guessed it, I have assembled them the other way. After some time contemplating this I don't believe that getting the cotters in the wrong way has any great impact on the position of the lever as the angle on the cotter is very small and will only rotate the lever very slightly, albeit in the undesired direction.

With reference to your issues I am sure that the actuating Brake Cam are definitely handed (though mine were also unmarked). I checked this during the assembly stages on my axle and found this to be the case.
My levers are well forward and come to approximately the 90 degree point when the brakes are applied. I had the drums turned and linings machined to match the new radius along with new cam bushes, springs etc.
Please keep us informed of your project. I can post up some pics if that helps.

Location: Victoria Australia

G'day Bruce (I'm a Bruce too!) et al. Well having stripped both sides down I can categorically state that there is bugger all difference between the two camshafts. Looking at them they're not much worn which suggests that they were replaced not too long ago by a former owner. The bushes are also perfectly serviceable. I wonder if they're perhaps from an A35?

This photo shows the two camshafts:



Having disassembled everything I placed both camshafts in a small vice to check to see if they were 'handed' or not. They aren't. The flat for the cotter pin is exactly square on to the camshaft flats.

However, one thing I did notice is that there is machining on one face only of the brake levers, to accommodate the cotter pin washer & nut - the other side is rough cast. What this means is that the cotter pins ARE meant to be inserted from the front and bolted up from the rear.

see here:

This is the machined side of the brake levers:


and this photo shows the unmachined & rough side which I presume is intended for the insertion of the cotter pin. The twist on the brake levers corresponds to the machined faces being towards the rear.



So, I think I might have to replace the camshafts (providing someone can verify that the new ones are definitely 'handed')

Location: Autumnal southern France

Hi Bruce,

you HAVE two identical unhanded brake cams which could be from any corner of the car.

You NEED two different, handed cams (which should be marked o/f and n/f)

These are available form the 7 Workshop for £12 a pair.

You will be amazed at how much this improves the brakes you have lived with for 30 years.

Hi Reckless,
I am currently rebuilding my 38 Opal, the cross tube needs to point upwards to clear the strenghtened radius arms. The cams on the brakes of mine are clearly marked n/s & o/s on the inner larger diameter end.The cotter pins are put in from the front. I would send you a pic but as my car has bowdenex cables it might confuse things further. Good luck

Location: North east hampshire

Ah well, at least the money will be well spent. It'll be nice having 'proper' brakes after all this time.
I'll keep you updated on progress.

Location: Autumnal southern France

Hi Reckless

Just to confirm what others have said.

This morning I examined the cams which my Father is fitting to his Ulsteroid, they are handed as described. the levers are handed, but only due to the twist making them align properly with the cables, the cotter hole is at 90 degrees to the arm.

All the best

Stuart.

Location: Devon

Bruce,

this shows the marking on an original brake cam, it reads"R/N"...



This shows three of the four configurations with the fourth missing as it is already fitted. It is a mirror image of it's partner.



I would suggest, looking at your photo, that you have none of these and yours has either been machined incorrectly or is from another vehicle all together.

There are definitely no markings or stampings on my two camshafts and like you say Ruairidh they look like they're probably from another car. That's why I thought about the A35 - only a guess but it did have rod operated rears or perhaps they're from a Big Seven?

Anyway I shall be on the blower to your Dad tomorrow.

Location: Autumnal southern France

No marking on my brake cams either but managed to sort them out during assembly. Pic of how the levers ended up.

Location: Victoria Australia

Thanks Ruairidh

Location: Victoria Australia

That certainly looks more like it! (Doubt if mine will look so pristine when I put it all back together.)

Nice job.

Location: Autumnal southern France

Bruce (Shearer) - why aren't your nuts painted? (Opportunity for further ribald comments) Cheers, Bill also in Oz

Location: Mount Eliza, Australia

Is that bits of card between the spring leaves, or masses of grease?

Location: Near Lands End, UK

Location: Victoria Australia

Location: Victoria Australia

Well I've had a nice present from our cherished suppliers and this evening I've put everything back together. I now have front brake levers pointing forwards as they should be. In the morning I shall endeavour to set up the front/rear brake balance. Everything is backed off at the moment - in the meantime can anyone answer me the following:

1. The front brake cable is mounted to the cross-shaft via the fork & clevis pin by means of a threaded rod connected to the compensator. On my car all there is to adjust the front cable is a nut on the end of this adjuster rod. Should there be something else, such as a spring or a locknut to prevent it working loose? (It's been like this for the past 25yrs by the way)

2. Setting up the tension in the cables - is it fronts first, then rears then handbrake? I just want to be clear before I go crawling under the car as vertigo takes over after a short while and it'll put me off my afternoon Pastis

Location: Autumnal southern France

Hi Reckers,
To answer number(1). When I had coupled brakes the nut to which you refer was a barrel nut, similar to the 3 inside the valvechest holding the block to the crankcase, this nut at it's (non-hex) end there was a hemisphere cut into the end of the nut such that it matched the profile of the pin through which it was threaded. In consequence of this, adjustment of the front cable could only be done in 1/2 turns but, the nut couldn't come unscrewed.

To answer (2).
Adjust the rears first, giving the nearside a slight lead. Then adjust the fronts to come on just before the rears. Check that the fronts don't bind excessively on either full lock.
I should say that's just how I do it, others may do it differently.

Ian Mc.

Location: Shropshire

That seems to make sense. It looks like someone (not guilty m'Lud) has lost the original & used a normal barrel nut. I think I might have to manufacture a new one. Presumably there should also be a compression spring on the other side of the clevis pin to prevent it working loose like on the rear brake adjuster rod?

Location: Autumnal southern France

I think mine might be slightly different. I think the adjuster rod (with the fork on the end the compensator rotates in) is threded into the barrel the sits in the arm that is on the brake cross shaft. TO adjust I need to take out the clevis pin, slip the quadrant out, loosen the nut and then rotate the fork in the barrel. The nut acts as a lock nut.

Hope this makes some sense.

Peter

Location: Shropshire

Well, as Renaud would say I'm going to "ceinture et bretelles" it and cobble something up to keep the tension on the nut so it can't work loose. Whilst it has been like this for years, now I know it's not right I shall worry about it until I've made it right. It'll just be my luck for it to drop off just as I'm about to hit the steepest part of the descent of "La Bonnette"

Mon Dieu!

Location: Autumnal southern France