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damen_red

520 rear brake woes.

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Hi all, my first major project on my recently acquired '68 520 was to redo all the hydraulics and related brake adjustments. I tackled the master cylinder and front brakes first and that seems to have gone OK, everything went back together and I have a good understanding of how the brake adjusters are supposed to work.

 

When I went to do the rear brakes I removed the brake drum and found them in really poor shape, there was metal on metal and lots of crud.  Upon closer inspection something didn't look quite right, here is a picture of what I found.

 

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After much head scratching and looking at the two service manuals I realized that they had installed the brake shoes upside down! So I cleaned everything up as best I could, and reassembled it to look like so.

 

5n4XOUEl.jpg

 

3JSupawl.jpg

 

HrhkwLTl.jpg

 

Now, I know these are still not quite right, first off, I missed hooking the small spring on the brake adjuster tang, but I have ordered all new hardware and brake shoes, so I will fix that when replaced. The one thing that I really need help with is how the emergency brakes go together, I am missing the piece the manual calls "Lever, toggle (L.H.)" and am not sure I have the "Link Extension" that connects to the cable placed properly. Does anyone know where I can get the missing piece and a picture of how these brakes should look stock. The exploded diagram is great for accounting for all the pieces, but I feel like a picture would clear a lot up especially considering I have never seen what a correct installation looks like. Is there a toggle lever on both sides? I haven't done the right side yet, but am expecting the same thing there too.

 

I have searched around and have most of what I need as far as information goes, but the one thing I am missing is a good picture of how the rear brakes go together because most forum posts no longer have the pictures included. Thanks in advance!

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Don't know if that helps, but I used that picture to do the same thing you're trying to do.

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5n4XOUEl.jpg

 

I would say they were correctly fitted to begin with as far as lining orientation on the leading and trailing shoes..

 

I believe the leading and trailing shoes are now reversed here. Looks like this is the left (driver's side) rear, therefore front is to the left in the picture. The lining on the leading shoe (left) should be farther from the wheel cylinder (top) than on the trailing side (right)

 

The one on the right should come off, be rotated to face the front and then put on the left side. The left done the same and put on the right. Ever noticed your brakes don't work as well while backing up? Having them reversed will cause the truck to brake better while backing up than going forward.

 

 

 Just remember that the front (leading) shoe has the lining farther from the wheel cylinder than the rear (trailing) shoe.

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I probably should have prefaced my post with saying I have never driven this truck, I towed it home about 9 months ago and it hadn't run for about 15 years. Everything is seized or locked up to some degree and I'm tackling it piece by piece. I didn't realize that there was a front-back orientation to these shoes, it's been a long while since I have worked on drum brakes. I'm hoping once I get the new shoes and hardware it will become clear which is front and which is rear.

 

As far as how they were originally fitted, I don't think there is any way that was correct. The slot for the parking brake toggle lever is below the wheel hub, as shown in this picture(red arrow):

 

f72mut0l.jpg

 

Also, you can see how the spring bends around the adjuster, which can't be right! It also shows in the service manual that the slots for the parking brake toggle lever are above the wheel hub, once I had oriented the shoes correctly(except for the previously mentioned Front-back orientation) everything went back together like a charm.

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If this is a long time non-running truck, buy new stuff.

 

Do not trust that any part of those brakes, as they currently sit, are safe.

 

 

I rebuilt every bit of my 521 brake system for less than $250. Worth every penny.

Cylinders, hoses, hardware, shoes. I rebuilt the adjusters myself and machined the drums at work.

The only part I did not replace was the main hard line.

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If this is a long time non-being truck, buy new stuff.

 

Do not trust that any part of those brakes as they currently sit are safe.

 

 

I rebuilt every bit of my 521 brake system for less than $250. Worth every penny.

 

Every part will be replaced, have no doubt! My problem here is that I have an incomplete system. I am using the old parts to mock up where the new parts will go while I wait for them to be delivered because I have no assurance that all the pieces are even there! Again, does anyone have a picture of a complete, correctly assembled rear brake system?

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I can try and take a pic later.... datzenmike has me questioning how I installed my shoes on my 521.. the whole leading/ trailing thing. .. I also have a 520 rear axle assembly in my basement should be easy to pop the drum off and have a look and snap a pic....

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That would be awesome, thanks! Brakes are the one thing I want to get absolutely perfect!

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Found this post too of someone looking for the exact same part, nissanparts.cc doesn't carry it any more, I'll try the dealer today now that I have the part number, thanks everyone for their input!

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Hit me on my user name and I can send a pic have a set off from rear disc modded truck ,Stupid face book bs.

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Called the dealer and they are no longer available, nissanpartswarehouse.com seemed to have them, never heard of them before, they took PayPal, so I placed an order anyways.

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Called the dealer and they are no longer available, nissanpartswarehouse.com seemed to have them, never heard of them before, they took PayPal, so I placed an order anyways.

 

That was quick! They already canceled my order, citing the same reason as the dealer.

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Well not gonna get those pics that 520 rear end I have is rustier than I realized ... drums are gonna need a lot of persuading, no idea if anything is even in there for brake parts, .... I bought it as a trailer because I needed the bed but I didn't wanna just throw the diff away....

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I can try and take a pic later.... datzenmike has me questioning how I installed my shoes on my 521.. the whole leading/ trailing thing. .. I also have a 520 rear axle assembly in my basement should be easy to pop the drum off and have a look and snap a pic....

 

Unless one or both were also replaced wrong. A 520 is old and has probably had several sets of brakes put on. And as they get older and older the owner starts to do the changing.

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Like Mike said same parts used into the mid 1980s.  You can get the parts.  Sometimes it takes some work to find the parts but they are out there.  Those are not wear parts so used parts are fine for Item #9.

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5n4XOUEl.jpg

 

It might just be me, or the picture, but the upper right part of the lining looks like it is separating from the shoe.....

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Is Item #9 the only part missing?  Do you need 2 for both sides.  Make a list of parts needed and I will see what I have.

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Well hopefully Charlie or someone else has you covered.... worse case senerio pm me ... I have that 520 axle assembly in my basement but I don't have the time to mess with it to see if any brake parts are still there...

Might have time in about 2 weeks if your still stuck....

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Is Item #9 the only part missing?  Do you need 2 for both sides.  Make a list of parts needed and I will see what I have.

 

Thanks! At this point I should take the other side off so I can see exactly what I am really missing, someone near me thinks they have some too, along with a seat, which is super awesome!

 

Well hopefully Charlie or someone else has you covered.... worse case senerio pm me ... I have that 520 axle assembly in my basement but I don't have the time to mess with it to see if any brake parts are still there...

Might have time in about 2 weeks if your still stuck....

 

Will keep you in mind, it's good to know where the parts are as I am just getting started on this one. Thanks!

 

As a side note, I replaced the rear brake hose with the Centric one from Rock Auto, the fitting that goes to the brass distribution block fit perfectly, but the one that goes to the hard line was rather difficult to tighten down, along with that the hex fitting on it was too small to fit in the recess and seemed to be a metric 17mm instead of the SAE fitting on the one that I took off. I went ahead and ordered the Beck Arnley one to see if it was a better match, along with some tubing and fittings in case I stripped the one that's on there. Anyone else here run into the same trouble? I am hoping that the nut is just tapered and seals as it tightens?

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On the last part ... what part are you talking about? Lost me a little....

I had issues with my 521 when I ordered new wheel cylinders.... should have been Sae everything said it was sae but what i received was metric... just be carefull...

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On the last part ... what part are you talking about? Lost me a little....

I had issues with my 521 when I ordered new wheel cylinders.... should have been Sae everything said it was sae but what i received was metric... just be carefull...

 

I'm talking about the rubber hose that goes from the hard line to the junction block that splits out the rear left and right brake lines. It appears to be SAE on one side and metric on the other. The end that connects to the brake line that comes from the front of the truck is definately not the same size nut as the one I took off.  I'll take some pics this weekend when I get the wheel off again.

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