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Drums that actually work? Anyone?


Guest 73Turbo240z

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Guest 73Turbo240z

Alright, as i've been putting around in the Z w/ the new HKS gasket, i've started to finally give the car good shakedowns to see what needs adjusting, so far the front brakes feel fine, though i need to go put some brake quiet on the shim pads to keep them from harmonizing at light braking.

 

however my rear brakes, they feel rather loose, the e-brake comes up substantially far in order to hold the car on an incline, and i feel like i'm not getting nearly the engagement i should on the hydrolic portion of the pad control either.

 

we got in there during the headgasket swap and used a flathead and mallet to rotate the rear wheel cylinder cogs a little bit, and while that helped, it still feels as if it could do better...

 

should i just take the rear wheels back off and do the cogs on the wheel cylinders some more? or is there a better solution?

 

keep in mind, everything is new, from brake booster, to rear wheel cylinders, i replaced EVERYTHING before i ever drove the car. and it's all bled properly, no air in the lines.

 

i'm really starting to hate these rear drums, it's making the drive to do some kind of disc upgrade pretty substantial, but i need to be able to park on hills, which seems to be the akilies heel of the upgrade since i think i lose my e-brake then, which would mean i'd have to do a line loc or somthing.

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Well Im sure that you know this but Ill just reitterate to be certain, have you properly adjusted your rear brakes? That will help substantially with the braking and with the parking brake.

 

The rear whells should have a slight bit of drag once assembled after adjustment.

 

Im not sure as I cant really recall if the parking brake cable on the 240z has an adjustment, if it does have you adjusted your cable? There may be slack and that could be the reason for you having to pull so far to get the ebrakes to engage.

 

They should come on pretty tight at about 65% of the throw of the ebrake handle.

 

As for stopping power there are several different pads that you can use that work well with the drum brakes.

 

You didnt mention whether or not if you replaced the drums as well, you may want to check to see if they are still in spec, and are not worn to the point that there isnt enough metal inside for the brakes to grab hold of.

 

Good luck and keep us posted on your progress.

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Guest 73Turbo240z

i'm relatively sure that they are assembled properly, between photo documenting how they were stock, and the FSM, i was pretty meticulous in re-assembly.

 

I recall the passenger side having more drag than the driver side. Though it was spotty, not through all 360 degrees of rotation however. I had the drums turned, and the meat on them was within spec i was told prior to turning. However i didn't have calipers to verify on my own with. So i'll have to look into that, but to answer your question fresh turns on the stock 73' units.

 

I think i might have seen somthing about an adjustable area on the e-brake in the FSM, i'll go back and re-read that section, if it is adjustable, it'll be somewhere near the lever i imagine, which w/ the driveshaft in now, should be fun to get too.

 

When i did initial assembly, i did multiple test fittings of the drum w/ the new brake shoes on there, i was getting drag at the very edges of the shoe surface as indicated by the fresh dust/markings when i'd pull the drum back off, it was rather noisy when we 1st got it driving, i attributed it to brake shoe wear in period on those corners, and as i figured, the sound diminished after about 5-10 miles of driving if i recall.

 

I've not had the drums back off since yet to check the wear pattern, perhaps i'll do that tommorow, it just struck me as odd that the setup on these rear drums was so haphazard stock, no real alignment that i can see, just wiggle it on till it fits in the indentation of the rear backplate.

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I think you may need to just adjust them out a little more. When I last reassembled mine, I started out like you with them just barely starting to drag. Before they would work though, I ended up having to adjust them out a good bit. You couldn't do it with the drums off then slip them on. You had to put the drums on and adjust through the little slot in the backing plates. It was actually a little hard to turn them until the wheel was bolted on, then there was enough leverage to spin it by hand. Up until that point I couldn't get the pedal high and hard. After that, the pedal travel was minimal and pedal was hard. Drum brakes only pivot on one end so the wear pattern is never going to be even across thier whole face. Just relating my experience, YRMV.

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You should be able to adjust the rear drums and the length of the E brake cable to allow the parking brake to work on hills. The 240's have decent parking brakes. If it is not working, then keep working on it until it does.

 

But if you go with the modern motorsport 240SX rear disk upgrade you will have a stock parking brake.

 

http://www.modern-motorsports.com/catalog/product_info.php?manufacturers_id=&products_id=2

 

There have quite a few other threads about people adapting Maximum brackets to use OEM type rear disk calipers with integral parking brake functions. so you don't need to give up on a parking brake to get rear disks.

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ok.... something is not assembled right... OR you did not understand the function of the automatic adjuster lever....

 

 

If your E-brake cables are in good order... then the rear brakes will adjust themselves with repeated pulls of the E-brake handle....

 

I am still running drum brakes on my 1972 240Z track car... I have seen a LOT of people new to Z cars having difficulty with the rear drum adjustment... you need to really sit down and look at how the lever engages the cog wheel adjuster...

 

This same lever can be "unhung" and then the adjuster can be turned with a screwdriver to loosen the shoes to allow them to come out of a worn drum.

 

during assembly I usually leave the adjuster in its "smallest" setting... Once I have everything assembled and the wheels are torqued to specs. I repeatedly pull the E-brake handle until I can no longer hear a clicking noise from rear brakes.... this is PERFECT preloading.

 

There is no other way to properly adjust the rear brakes... period.

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When I reassembled mine on my 280z, you could actually hear the rear adjusters clicking when I pulled the parking brake handle.

 

My handle comes up quite a bit, but the parking break holds good.

 

Pedal feel is better then my ZXs, but the fronts squeal quite a bit. I also need shims and I need to regrease them.

Mario

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