Jump to content


Photo
- - - - -

battle of the 240z brake drum


  • Please log in to reply
13 replies to this topic

#1 rinigado

rinigado

    Newbie

  • Members
  • Pip
  • 47 posts
  • Location:LA

Posted 03 December 2016 - 07:33 PM

This weekend, I'm getting a start on sorting out all the problems that accumulate after the 22 years that my 240z has sat without running. First up were my stuck rear wheels. I spent some time this afternoon pounding, heating and prying the first of the brake drums off (driver's side). I ran out of daylight to work on the other side, so that's a fun job for tomorrow morning.

 

Now, I've put the drum back temporarily until I can get some new shoes. To do so, I had to turn the adjuster wheel on the wheel cylinder all the way back in to get the shoes pulled in enough to get the drum back on. I'm nervous about what the fit when I put in new, thicker shoes!

 

Next step will be to find some new shows, and turn the drums to get them cleaned up. Turns out the PO had a second set of brake drums shipped to him from someone, and they were sitting in a box inside the car. They're used, but I'll get both sets measured and pick the best pair. And I'll need to start replacing some cracked brake hose sections. I'm sure there's more once I check more of the car, but the rear hoses for sure need replacement.

 

Regarding the drum wheel cylinder, is there a good way to test the cylinder, or should I just wait and see if the parking brake holds rear brake tight? I'm guessing it's probably also not a bad idea to buy a new set of springs and clips for 15 bucks while I'm in there in case the return spring is a little tired.

 

 

 

 



#2 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 63,709 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 03 December 2016 - 08:34 PM

Replace the cylinders, they might easily begin to leak next week, next month.

 

Be sure the mechanical adjusters are backed all the way off and  the emergency brake is not only off and the adjuster loosened, but that the e brake cable is not rusted within the sheath and not releasing.


Posted Image

#3 rinigado

rinigado

    Newbie

  • Members
  • Pip
  • 47 posts
  • Location:LA

Posted 03 December 2016 - 09:46 PM

in the case of the wheel today, the parking brake cable was disconnected from the wheel cylinder lever, so it seems like it was a combination of things just being seized together, and the wheel cylinder not being turned all the way in. Hopefully it'll only take about half a million whacks with a hammer tomorrow to get the other side off.

 

I'll add a pair of wheel cylinders to the growing rock auto shopping cart.



#4 MikeRL411

MikeRL411

    78 'n counting...

  • Senior Member
  • PipPipPipPipPip
  • 4,913 posts
  • Location:Rancho Palos Verdes CA
  • Cars:67RL411, 90 240SX, 97J30T

Posted 03 December 2016 - 10:33 PM

in the case of the wheel today, the parking brake cable was disconnected from the wheel cylinder lever, so it seems like it was a combination of things just being seized together, and the wheel cylinder not being turned all the way in. Hopefully it'll only take about half a million whacks with a hammer tomorrow to get the other side off.

 

I'll add a pair of wheel cylinders to the growing rock auto shopping cart.

 

For longevity, use a plastic shot filled "dead" hammer, not an iron headed hammer!  One of the white rubber hammers is a good second bet.  Hammering with an iron hammer can crack the drum.  Check to see if the drums have tapped holes to use bolts to lift the drums away from engagement [spoken from ignorance as to 240Z drum characteristics].



#5 rinigado

rinigado

    Newbie

  • Members
  • Pip
  • 47 posts
  • Location:LA

Posted 04 December 2016 - 07:56 AM

yep, I was using a softer hammer after seeing that advice on some older threads around here. Unfortunately there weren't/aren't any extra holds to help pull the drums off.



#6 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 63,709 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 04 December 2016 - 09:58 AM

You could try heating them also. Makes the hole around the axle larger from expansion.


Posted Image

#7 flatcat19

flatcat19

    Back in Black

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 17,725 posts
  • Location:Tri-Cities, WA/PDX
  • Cars:Smaller. Better. Slower. Lower.

Posted 04 December 2016 - 01:00 PM

HF sells big jaw pullers. That's what I used to remove the drums on my 521.

May need a 3rd or 4th hand to hold the jaws as you tighten the bolt.



If doing brake work on an unknown system...just replace all of it.
Brake parts are not all that expensive through rock auto.

Peace of mind isn't as expensive as one would think.
I replaced every bit of my brake system for less than $250(all 4 wheels.)
I machined my own drums, bent my own hard lines, rebuilt my adjusters and replaced everything else. Springs, cylinders, hoses, shoes, clips.

You can't hang if your nuts haven't dropped...it's physics


#8 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 63,709 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 04 December 2016 - 02:17 PM

I don't know about the Z car drums but most others have two threaded holes across from each other. Takes a 10mm? head metric bolt. Tighten in the bolts and they bottom out on the axle flange beneath the drum and force the drum out and off. Have a care! They are only small and you can strip them. In addition they can also tear the anti rattle pins out of the backing plate if the shoes pull outward too. 

 

I tighten the bolts and then hammer around the outside of the rim to loosen what will loosen, and then tighten up any slack and repeat. Slowly the drum moves outward and the shoes are exposed.

 

I did have a really old drum that just had to come off. Everything e brake and shoes seized to hell. I tightened and slowly tore the shoes and all right off the backing plate.


Posted Image

#9 rinigado

rinigado

    Newbie

  • Members
  • Pip
  • 47 posts
  • Location:LA

Posted 04 December 2016 - 05:19 PM

got the second drum off today. I wasn't as lucky on the positioning of the little access hole on the 2nd drum..it wouldn't turn at all and the hole was nowhere near the wheel cylinder adjuster, so no chance to back off the wheel cylinder. Some heat and pb blaster and hammering, same as before, but this one only took about 100000 whacks to get it done. A relative piece of cake compared to yesterday! 

 

Unfortunately, at least on my brake drums, there are no extra holes to put a bolt through to push the drums out. You'd think they would have figured out to put a hole on the back plate to get at the wheel cylinder.

 

As far as replacing the works, I was thinking the hard lines would likely be ok, but is the consensus that it's worth replacing those as well?



#10 flatcat19

flatcat19

    Back in Black

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 17,725 posts
  • Location:Tri-Cities, WA/PDX
  • Cars:Smaller. Better. Slower. Lower.

Posted 04 December 2016 - 05:27 PM

Hard lines should be fine. I left the main line in mine.

The reason I replaced lines was because of stripped flare nuts or kinks in the lines.

You can't hang if your nuts haven't dropped...it's physics


#11 rinigado

rinigado

    Newbie

  • Members
  • Pip
  • 47 posts
  • Location:LA

Posted 27 December 2016 - 12:51 PM

is there anything to be careful of when taking the aluminum drums to a shop to be resurfaced? I assume the inside surface of the brake drum is still a steel/iron liner? I had one shop tell me they couldn't turn an aluminum drum, so wondering if there's any trick to working on these?



#12 flatcat19

flatcat19

    Back in Black

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 17,725 posts
  • Location:Tri-Cities, WA/PDX
  • Cars:Smaller. Better. Slower. Lower.

Posted 27 December 2016 - 01:07 PM

The inside lining should be steel. Place a magnet on it to verify. 

 

Take them elsewhere to have machined. And don't tell the monkey at the counter that they're aluminum. Just that you want your drums machined. 


You can't hang if your nuts haven't dropped...it's physics


#13 rinigado

rinigado

    Newbie

  • Members
  • Pip
  • 47 posts
  • Location:LA

Posted 27 December 2016 - 06:38 PM

I found a brake guy that's cheaper and should get it done no problem. I'm gonna take the drums and rotors in tomorrow to him to get them cleaned up. One of the boxes of stuff that came in the car had a pair of similar rotors. They don't look exactly like the ones I pulled off, but overall dimensions are the same, and the brake surface still has more thickness. The raised hat section has a bit of a different profile with some cutout sections. The one on the left was pulled off the car. The one on the right is one of my new mystery rotors:

 

IMG_0231_zpslwqb9str.jpg

 

Getting the rotors and hubs separated was a pain in the ass, but someone over on classiczcars forums posted something about using a cold chisel to drive in between the ends of the studs and the rotor surface, and working your way around the brake, slowly driving the pieces apart. That worked like a charm.



#14 Ranman72

Ranman72

    Datsun Mechanic

  • Senior Member
  • PipPipPipPipPip
  • 5,414 posts
  • Location:Citrus Heights
  • Cars:68 datsun 510 2 door / 69 Datsun Roadster /05 350z / 08 f350 / 73 datsun 1200 coupe

Posted 27 December 2016 - 10:35 PM

I found a brake guy that's cheaper and should get it done no problem. I'm gonna take the drums and rotors in tomorrow to him to get them cleaned up. One of the boxes of stuff that came in the car had a pair of similar rotors. They don't look exactly like the ones I pulled off, but overall dimensions are the same, and the brake surface still has more thickness. The raised hat section has a bit of a different profile with some cutout sections. The one on the left was pulled off the car. The one on the right is one of my new mystery rotors:

 

IMG_0231_zpslwqb9str.jpg

 

Getting the rotors and hubs separated was a pain in the ass, but someone over on classiczcars forums posted something about using a cold chisel to drive in between the ends of the studs and the rotor surface, and working your way around the brake, slowly driving the pieces apart. That worked like a charm.

just double check the backspace on the rotors the early stock rotors have the slots you see the aftermarket ones might not 

but the 280z had a different offset and no slots either