510 rear drum brakes locked

[Wolfman]

1971 510. 
 

issue: rear brake on driver side is seized and rear passenger side does not engage.
 

Beating the drum with a hammer frees it up but immediately locks up again after pedal is applied. I have taken it apart and cleaned it up. The side that seized looked like it was covered in black grease.

 

I can engage the passenger side if I pull on the cable by hand underneath the car but not with the break pedal 

 

this happened after I replaced the front break pads, not sure if that helps. 
 

tried bleeding but nothing changes. 

[datzenmike]

Replace both rear wheel cylinders and probably the shoes as well. The black stuff is burnt brake lining and leaking brake fluid.

[paradime]

I agree with Mike about the black tar being leaked fluid, but what caused it? Assuming there was no issue before the front pads were replaced, did this start happening immediately or over time? Did you bleed the lines after replacing the front pads? Could something have gotten into the driver side rear cylinder?

[Wolfman]

Just ordered new brake cylinders. I got this car over ten years ago and only drove it briefly before parking it. got it running again recently and only drove it around the block a few times before I started replacing parts (coil overs, control arms, tc rods etc.) figured I’d do the brakes while I was at it. So I’m not sure if the rear breaks ever worked properly. I did not bleed after I replaced the front, pumped the breaks a few times to build pressure back up while I was rolling out the drive way (yes I forgot to do this before putting it in gear) and then the rear driver side break locked up. Pounded off the drum and messed with it got the car to roll, jacked it up and put it in gear and found out neither wheel stopped when putting on the breaks. Tried bleeding and messing with the shoes a bit and the left locks up hard while the right doesn’t engage at all…. Long way to say that I’m not sure when the breaks went to shit.

[Stoffregen Motorsports]

Check the adjustment at the brake pedal.

[Wolfman]

1 hour ago, Stoffregen Motorsports said:

Check the adjustment at the brake pedal.

The rubber stopper thing or is there an adjustment somewhere else?

[datzenmike]

Push on the brake pedal with thumb. It should just barely move 1/16" maybe 1/8" before there is firmer resistance.

[Stoffregen Motorsports]

Both actually. If the rubber stopper has ever been adjusted, it could be that your pushrod needs adjustment too.

 

If there is not freeplay at the master-to-pedal pushrod, the master won't release pressure, causing brakes to lock up.

[Wolfman]

The play in the break pedal seems fine, I can push it with my thumb a small bit before it starts to stiffen up. I got new brake cylinders but I’m not sure if they are correct or not. The shiny part on the back of the cylinders sticks out and doesn’t allow the pad the sit in a slot. The old ones have the same piece but it is much farther in. Pics for reference 

 

[banzai510(hainz)]

so your saying the slot that the shoe blade part rides in is not Deep enough? I can see it. Maybe the sand casting in China is wearing out and got less deep.

 

try another brand is the nest best if possible.Sometime rock auto wont deal with shipping back and still refund you.

 

find Nabco or Tokico ifeven possible

[banzai510(hainz)]

this one look a little deeper by the photo,but im till leary of these parts

https://www.ebay.com/itm/204059711975?hash=item2f82e819e7:g:~BYAAOSwbjxi6YTG&amdata=enc%3AAQAIAAAA8B4qCFn0XpwEcXoXVQIkG%2BpobNSgeqvHadQOjLUgyz4yNuSC4hw80lgzmsbIMm%2Bw65pi8zB4pDNmbT%2FIxTvLNyfHfB83uaTJZc07yWwQQfpABovB6W13yXTmmSapMN88jVETLCKvkS%2F4%2FKmBTcrbUKZeF6w69ujL9Aa8Rd%2B6imbXImwnjcxd8DdYCf%2BG8D3OhgfHZ6tpURKx9OV1AQyvoUC%2F4RTHP1LgFs162DneMqWHLtXvkJshPMR4nBjcDTjRPFdYi%2FzFbN41ENFaWdA%2FqtERrouP4OdZ4mxCCSta%2BjcmJXn4ELFBAvP1wJ0HFOk8Xw%3D%3D|tkp%3ABk9SR5qKkM-NYg

 

Edited May 30, 2023 by banzai510(hainz)

[banzai510(hainz)]

beck arnely is to be a better brand, but cant tell by the photo

https://www.partsgeek.com/scxrbs6-nissan-510-wheel-cylinder.html

[banzai510(hainz)]

is this a wagon or a sedan?

 

do you think the cylinder was leaking alot?  id greasy black then yes I say its bad. but soemtimes the cylinder where it rides on the plate and loosen up then not center itself. the clipsin back have to have enought tension to move but NOT by hand once installed

 

alotof photos of the drum rear brakes would help

Edited May 30, 2023 by banzai510(hainz)

[Wolfman]

1 hour ago, banzai510(hainz) said:

so your saying the slot that the shoe blade part rides in is not Deep enough? I can see it. Maybe the sand casting in China is wearing out and got less deep.

 

try another brand is the nest best if possible.Sometime rock auto wont deal with shipping back and still refund you.

 

find Nabco or Tokico ifeven possible

Yes that is what I meant, I looked at a bunch of pictures of different brands and they all seem to look the same. Even found a video of a guy doing a replacement and his look the same. Just seems weird there is literarily no lip fit the shoe to fit in. My car is a 4 door 510. 

[Wolfman]

1 hour ago, banzai510(hainz) said:

is this a wagon or a sedan?

 

do you think the cylinder was leaking alot?  id greasy black then yes I say its bad. but soemtimes the cylinder where it rides on the plate and loosen up then not center itself. the clipsin back have to have enought tension to move but NOT by hand once installed

 

alotof photos of the drum rear brakes would help

The driver side had greasy black residue everywhere, I had already taken it apart and cleaned it up or I would take pictures.

[banzai510(hainz)]

its been awhile (15years)since I did my back brakes and my spare Jap made cylinder are in the rafters so I cant check to see if these are correct what you got. or maybe the quality of the parts has degraded over time.

[Wolfman]

If I can’t find better ones or if the replacements are all like this… should I file it down a bit or just run it as is?

[banzai510(hainz)]

I thought the same but dont really know.

 

is that spring loaded or it moves out when brakes applied the black end is obvious but the other I just forgot as there should be a seal of some kind

[Wolfman]

On 5/30/2023 at 10:18 AM, banzai510(hainz) said:

I thought the same but dont really know.

 

is that spring loaded or it moves out when brakes applied the black end is obvious but the other I just forgot as there should be a seal of some kind

I’m not sure either, put it on just to test it out and I can’t get the drum back over the shoes. Adjustment screw at the top is pretty seized but I believe is all the way out anyways. 

[banzai510(hainz)]

the adjustment screw (spreader at top) think its a 7mm square  one can use vise grips and soak it with anti seize.or I had a beat 510 i had soemone weld a 12mm or 14mm nut on there then was ezer to turn once you soaked with PB Blaster

 

 

yeah this photo dont lookright with the slot not being there

Make sure you have the front side or back side shoes on the right spot.I cant remember now myself been so long

[datzenmike]

 

My 710 rear adjust won't be exact but the square screw head was well worn and almost round, making adjustment a bitch. Finally said the hell with it and welded 13 or 14mm nuts on. A ratchet is much easier. Covered all threads with anti seize.

 

 

 

Just fit the cylinders. The shoes can't slip off as they can't move laterally. The hump is hardened steel to prevent contact wear that the aluminum casting would never survive.

 

Make sure the e brake is loosened off slightly and tap the wheel cylinders forward or back to center them so the shoes will fit inside the drum.

[Wolfman]

took off and  soaked the adjustment bracket/screw in wd 40 in a cup for over a day… absolutely would not budge. I ended up taking out the little pieces that press out when the screw is turned. The hub went back on and the breaks work great… how ever am damaging the bracket without those parts?

 

 

[yenpit]

Is your 510 4dr a USA spec car with independent rear suspension OR a Mexican spec car with leaf springs?  I would expect that the rear wheel cylinders (RWC) are different.........??

 

Worst case scenario, if USA spec IRS, I will have USED wheel cylinders (might be factory OE or early aftermarket) & I MIGHT have some NOS RWC rebuild kits (just rubber bits).  See if you can buy rebuild kits & PM me what you might need..................

[datzenmike]

On 6/18/2023 at 1:13 PM, Wolfman said:

took off and  soaked the adjustment bracket/screw in wd 40 in a cup for over a day… absolutely would not budge. I ended up taking out the little pieces that press out when the screw is turned. The hub went back on and the breaks work great… how ever am damaging the bracket without those parts?

 

 

 

You can't run without the adjuster set properly. The bottom ends of the shoes will wear away the soft aluminum adjuster body.

 

 

Take the adjuster out and weld a 14'' nut on the end. Heat the adjuster with a torch. Aluminum expands 2X what steel will. When hot the hole is larger and has less grip on the steel adjuster. It'll come loose.