Pads and Booster

[ramsesosirus]

Did some work this weekend, reman booster new master cylinder, new pads (organic) added shims.  Rear wheel cylinders and shoes all new within the month.

Been trying to solve a weak and squealing braking issue for a long time: brakes feel better, still some squeal.

I swapped the semi-metallic pads with organic pads with some shims to try to quiet the brakes.  Any advice on pad construction/type?  The semi metallics squealed horribly, but didn't have the shims.

^^^^^^^^GREAT design by Nissan, I didn't know, but you can change the pads without removing the caliper on the early Z cars!  Just compress the old pad back in with a clamp and pull them out with pliers!  Easy.   (Some of you know this)

Also, I couldn't afford a "new" booster, some of them are expensive... Autozone was the only one that could order me one.  Advance, Oreilly, and Napa all had one listed, but none available.

It was about $130 including the core, you get a discount if you spend over $100 so it was about $160 for the reman booster and the "new" master with the reservoirs (not OE style lids).  

It is painted black too, looks nice.  I would recommend this part.  I think my reaction disc had fallen out of my old one, I know you can fix that, but I went with the piece of mind of a reman one since it was 40 some years old.  Core was only $30 so I will just keep the stock one.  Vacuum port seems to be in the stock location as well, which I've heard isn't always the case for reman ones.  

 

I feel like my rears are adjusted out quite a bit, yet don't seem to grab?  Would the cylinders be able to "back adjust" if it was set too tight?  

how exactly should great working stock Z brakes feel?  Should I be able to "lock" the brakes?  

Thanks in advance, and I hope this helps someone else.  

 

[Patcon]

You can also use some antisqueal sealant on the back of the pads even with the shims. One that comes to mind is something like CRC disc brake quiet

 

42 minutes ago, ramsesosirus said:

Should I be able to "lock" the brakes?  

Yes, I would think you should be able to lock all four...

[Zed Head]

59 minutes ago, ramsesosirus said:

I swapped the semi-metallic pads with organic pads with some shims to try to quiet the brakes.

 

Are they the stick-on shims?  Glued?  This topic comes up often.  I couldn't get anything but the Nissan free-floating shims to stop my squeal.

[ramsesosirus]

They are the stick on shims.  I've bought several sets of pads, this "Brake best" set was the only one that included shims, the car never had them since I've owned it and the front brakes always squealed.

I plan the reuse them, I'll have to peel them off the pads and use something to glue it to the new pads.  Motorsport has some listed, but they are unavailable.  I'm lucky the set included these, I would've never knew...

Perhaps my squealing issue was more due to the lack of shims that the semi metallic pads.

How exactly do the shims eliminate squealing?? 

 

[jonathanrussell]

I personally don't see how the stick on shims would work or how they would be different from having no shim.

I have found that something similar to the stock Nissan shim plus a light, full coating of brake grease / anti-squeal grease on both sides of the shim where contact is made with the pad and the caliper piston works.

I have thought about why it works and I have a few theories but none are based on anything that really warrants sharing.

[Patcon]

The noise is vibration and some how the shims mitigate the vibration. I don't totally understand it, some things I just accept at face value and move on. I am getting too old to sweat some of this...

[ramsesosirus]

14 hours ago, jonathanrussell said:

I personally don't see how the stick on shims would work or how they would be different from having no shim.

I have found that something similar to the stock Nissan shim plus a light, full coating of brake grease / anti-squeal grease on both sides of the shim where contact is made with the pad and the caliper piston works.

I have thought about why it works and I have a few theories but none are based on anything that really warrants sharing.

That's where I'm at.  That's why I never really thought about the shims causing the squeal.  

Mine squeals pretty bad, not all of the time, but enough to be annoying (and makes me look like I need brakes to other drivers).

After changing the semi metallics with organics and adding the stick on shims, I drove around the block once, and it didn't squeal, so it appears the shims do fix the issue.  I just stuck them on, didn't use any brake quiet or grease.  I may switch back to the semi metallic pads after a good test drive later this week.  

The organic pads from Autozone (Part D161, $15.99) includes 4 shims.  They're not exactly the same as the OEM ones, but similar and they fit.   For those in need of shims, this kit is pretty much worth it just the get the shims alone.  This is the only set I've gotten that included shims.

I plan to carefully pry them off and reuse them when the pads need changing.  Will probably have to "glue" them on when re using them.

 

 

 

[Zed Head]

You're on the same path that many of us have been on, trying to rationalize a solution, and trying to make what the other manufacturers say should work, work.  But they often don't work.  Often.

So, just to plant a seed, so that it might grow as you're braking up to a light and hear the squeal starting again, on some sunny fall day in the future, I'll post one more time.

Here is what always works - http://www.thezstore.com/page/TZS/PROD/24-5450

Remove the little tab and you can use it on either side.  The tab is just a locater, for convenience.during installation.  Also, note how the shim only covers about half of the caliper piston.  So there's actually a small bending force across the pad during force application.  Maybe that's a clue.  Who knows.

 

 

[ramsesosirus]

3 hours ago, Zed Head said:

Also, note how the shim only covers about half of the caliper piston.  So there's actually a small bending force across the pad during force application.  Maybe that's a clue.  Who knows.

Yes I find that the oddest part, that the shim only covers about half the piston.  Other cars I've done pads on, the shim is usually the size of the pad.

The autozone shims I got also only cover half the piston, but they cover the top half only as opposed to the Nissan one that covered only the left or right half.  I wonder if this makes a difference...

Thanks

 

[Captain Obvious]

When I first got my car, the front brakes squealed. When I dug into it, I found that my PO had put the anti-squeal shims in backwards. I switched them around to the proper direction and the squeal went away like magic. Poof.... One way they squealed, the other they did not.

The point being... Yes, which part of the piston that is covered by the shim DOES make a difference.

[ramsesosirus]

43 minutes ago, Captain Obvious said:

When I first got my car, the front brakes squealed. When I dug into it, I found that my PO had put the anti-squeal shims in backwards. I switched them around to the proper direction and the squeal went away like magic. Poof.... One way they squealed, the other they did not.

The point being... Yes, which part of the piston that is covered by the shim DOES make a difference.

Wow, good input.  Are those OEM style ones available anywhere?  Mine are long gone, and Motorsport has none available...

I just remembered the college I work at just got some new CNC milling machines that can make engine blocks... surely it can produce some OEM style shims, if I had one to scan, or the measurements.  Are they made of steel, kevlar, rubber??  

Oh captain my captain, which side of the piston contacts the shim?  Front of car or rear of car side?  Is the arrow pointing to the front of the vehicle?  (This is a good point for Captain Obvious to lay down the law that yes, the arrow obviously always points to the front of the vehicle..... haha)

[Captain Obvious]

Haha! Well the arrow doesn't necessarily point towards the front of the vehicle (because the caliper doesn't mount exactly on the top of the rotor), but it does point in the direction of wheel rotation (when the car is moving forward).  When the calipers are mounted on the car, the shims contact the piston from approximately the 8:00 position to the 4:00 position. (Does that make sense?)

I don't know for sure what material they use for the OEM shims, but I don't think they rust, so they are probably stainless steel or thin aluminum. I don't know what grade, but it is not one of the dead soft malleable grades. There's a temper to it. They would be a breeze to cut using water-jet or laser. You could mill them on the CNC, but water-jet or laser would be much faster and easier.

Edited August 30, 2017 by Captain Obvious
Added probability that the shims are stainless, not aluminum