240Z/240K rear brake drums interchangeable?

[Z Kid]

You only need half the shims they supply you with to get them to hold on too . Its not difficult but make sure you invest in a flare wrench (ring spanner with a side missing) for the 10mm brake line nuts. Round one or four of them off and life starts to suck that little bit more.

Chris

[Alfadog]

OK so the wheel cylinders are NLA from Repco/CheapAutoSpares. Going to have to have them resleeved instead.

So in the mean time, here are some photos. Not particularly exciting but I like to document everything.

1. Appearance with stock drums

2. Stock setup

3. Backing plate bent back, sanded and painted

4. S30 finned drums on

5. Appearance with S30 finned drums

[Z Kid]

I would be inclined to ring PBR for new cylinders before going the resleeve option. Surely they must be available somewhere, failing that whack a set of ZX discs on the back and be done with it . Happy brake work, and make sure you dont get any of that fluid on your nice shiny paintwork .

Chris

[Alfadog]

The old guy at Cheapa Auto Spares looked in the new (PBR) catalogue and couldn't find it, then looked in an old book that had it, but after comparing to new book saw that it was no longer available?! I thought it was strange too, but usually they're pretty good with this kind of thing. Repco had one for a 1600 but that's it... I probably could have got some eventually but I'm pretty sick of this. It started out as just something to do one afternoon when I was bored.

Anyway, they are at a resleeving shop now being rekitted so I'll have them back by tomorrow. Hopefully they'll go in as easily as they came out - and hopefully it all WORKS.

After seeing how it all works, I'm curious (oh God not again). Why is brake fluid such a nasty nasty liquid? Like, why does it have to be used instead of anything else? Potentially stupid question........

[Z Kid]

Seems odd, but I guess there isnt a demand for them that much at the moment. I have a damn resleeved cylinder on the landrover, which since resleeved has always stuck when left for a week or so without being used, might have just been done poorly, admittedly it does come unstuck after a few heavy applications, but until then it throws the car horrendously off balance and spears it across the road .

Brake fluid has to be pretty good at what it does, it has to have a super high boiling point, because when it boils your brakes are no more, it shouldnt absorb water too much (But it does and should be changed yearly or so), it has to maintain dimensions as the temp changes because if not as the wheel cylinder heats up on braking it will increase pressure and lock a wheel. It also cant be allowed to freeze (not an issue where you are). And has to be non damaging to the braking system. I think that new silicone brake fluid will not damage paint, but if used in an old braking system (any old parts) something will react and seize up everything.

Oh the joys of brakes, thats what the manual box is for

[Alfadog]

OK, so I got the wheel cylinders resleeved and I managed to install everything back together. Now trying to bleed the brake lines...... but they won't bleed! Dad pumps the pedal, I let the fluid go from the bleeder. Did so until a steady stream spurted out. Did both sides... Used quite a lot of brake fluid in doing so... but the pedal is still spongey. Pump it a few times and it's good, but becomes spongey again very quickly. I can't believe the lines are STILL not bled properly... could it be anything else?

If only life had an undo button.

[440k]

What's the exact process you used for bleeding the brakes?

I always get the helper to give it a couple of pumps and hold pressure. Then I crack the bleed nipple (enough to let the fluid run out, yet maintain good pressure in the lines), and let it drain. Before the pedal gets tot he floor, I tighten the nippple again, so that it can't suck air back through the bleed nipple. It is very important to keep pressure in the brake lines, so that you can't suck air back in. Did you do that? Also, make sure the fluid reservoir is always topped up, so it can't suck any air in.

Another method I recently heard was to use a large syringe with a rubber hose, and suck the old fluid out through the nipple. Again, keep the fluid topped up in the reservoir. I have never tried this method, so can't comment on it, but it sounds logical.

If you've properly bled the brakes, then your back drum shoes probably need adjustment (the new drums may be slightly more worn than the old ones). The back brakes aren't self adjusting, so no matter how much you bleed the brakes, they will always feel spongy.

You'll see the adjuster in your picture where the drum is off, at the top of the assembly, where the tops of the brake shoes pivot. This has bolt coming from the back, which has a tapered head on it (between the 2 pistons that locate the upper ends of the brake shoes). This can be screwed in or out to adjust the brake shoes (although it's best to remove all load from it before trying to adjust it, as it will probably be very tight and rusty).

This could be the problem.

[sakijo]

Did you bleed all the brakes and not just the back ones?

Are the cylinders in properly? It may sound stupid, but a friend of mine had a similar problem with his VW. Tried everything and still had spongy brakes. Another friend helping out noticed that the cylinders were upside-down. That made it impossible for them to bleed the air out because the nipple was at the bottom.

I use the "glass jar and tube method." I fill a glass jar with clean fluid - about an inch or so. Then I slip one end of a length of tubing onto the bleeder nipple and the other end into the glass jar. I crack the nipple a bit then step on the brake pedal or sometimes push with my hand. When it stops bubbling, I close the nipple and move on to the next one. The fluid in the jar keeps air from entering the system while allowing air to be pushed out. It's also convenient when you don't have a helper handy.

[khughes]

lachlan,

I managed to buy a set of new cylinders from repco in August 2004. they were from memory very cheap at around $30 each..

I have a set off my project car if you want them? not sure what state they are in but they are intact!

did you bleed all the wheels, closest to furthest?

[Alfadog]

I thought the front and rears were on different lines? There are two fluid cylinders..? We only bled the rears. The fronts need it too?

Thanks for the offer Kent, but it's too late now! The reconditioned ones should work fine (at $40 each no less ). I had some on the parts car too but thought new/reconditioned ones were probably a wiser choice. The cylinders won't fit upside down so that's good.

Thanks guys for the advice. Will have another go when I can...

[Zedrally]

I thought the front and rears were on different lines? There are two fluid cylinders..? We only bled the rears. The fronts need it too?

...

No..........

[sakijo]

did you bleed all the wheels, closest to furthest?

We were taught to bleed opposite - furthest to closest. Ah . . . . the joys of wrenching - there are so many methods . . . . .