Lomax rear brake replacement

[hotfoothowell]

Just replacing the brake cylinder and brake shoes on the rear wheel of my 1979 2CV6 based Lomax after complete brake failure (on a busy roundabout -an exciting moment!), using all new parts. However, the two central springs which are kept in place with a pin and cap are dead slack, and I'm reluctant to complete further assembly without advice. I have checked them against the originals, and all parts are identical.
I am not sure how the flanged collars on which the shoes pivot, at the bottom of the drum, go in, flange at the top (so that the nuts bear on them), or flange inwards. Either way, doesn't seem to make any difference to the tightness of the springs. Unfortunately, I did not see which way they came apart, and the Haynes Manual doesn't help. Any suggestions, please? Thanks, Patrick

[Paul]

Hi Patrick,
i don'tknow if this will help. but it's the only photo I have and it's of someone else's set-up. I did take some photos of mine for reference some time back, but I can't find them so assume they've been accidently deleted. However, if they do turn up I'll post them. The photos shows the left side rear brake plate assembly.

Rear drum brake plate pict0029 resize.jpg (50.32 KiB) Viewed 16145 times

Regards Paul

[Paul]

Hi Patrick,
Another view that may help. Copied from the 'Maintenance Handbook for Citroen Twins' by John P Richards C.Eng M.I. Mech E. Reproduction is poor as was the source.

Rear brake 2CV.jpg (72.02 KiB) Viewed 16110 times

Regards Paul

[hotfoothowell]

Managed to re-fit the col springs on my rear brakes, boy, what a daft design, and what a struggle. Did they make a special tool for this? Patrick

[Paul]

I usually manage to fit the slotted cap (item 15) with a pair of pliers. I'm pretty sure I've seen a tubular tool that sits on top of the cap; the tool is depressed and turned through 90 deg to engage the steady pin (item 9). A bit fiddly, though, occassionally everything flies apart and you lose the spring. One of the joys of DIY.
Regards Paul

[hotfoothowell]

I notice that the spring caps on the front brakes have two holes to engage with circlip pliers or the like - makes a lot of sense. Patrick

[hotfoothowell]

Having now replaced all three wheel brake cylinders, along with the brake fluid, I have bled the brakes several times, and although no further air is coming out of the system, the brakes still require two pumps before they activate. Can anyone suggest what I am doing wrong/ not doing, please? Patrick

[Colin-gser]

Hi

Have you centred the brake shoes? This needs to be done carefully and could give the symptoms you have assuming pumping the brakes is taking up the 'slack' in the drums before the shoes bite

I made a tool up for this - length of threaded rod welded to an old axle hub nut with an 'arm' between two locknuts, fit brake drum and adjust shoes on eccentric adjusters, take off drum and using tool adjust eccentric flange nuts on shoe so shoes sit centrally then refit drum, torque up and check eccentrics

Before you check that you could check for airlocks in pipes - I use a syringe and rubber hose on bleed nipples to push brake fluid up to master cylinder which usually clears any air better than bleeding

Finally if you have replaced all brake cylinders and any shoes/pads it will seem spongey for a while

Hope this helps

Colin-gser

[Paul]

Patrick,
If it helps for bleeding the brakes again, I 've used a Europat Vizibleed Bleed Aid. The non-return valve meant it was brilliant when I bled the rear brake. No more two people; one on the pedal and the other tightening and slackening the bleed nipple. The job was done in a couple of minutes and no air in the system. See http://www.halfords.com/webapp/wcs/stor ... 55218#tab1

Other than that, I can only agree with Colin-gser's advice.

Regards Paul

[hotfoothowell]

Thanks for your input, chaps. Patrick