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rinigado

My island turquoise 521

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And Daniel if the manual comment was for me yes I have plenty of books to refer to. This is all a simple question/ statement gone bad...

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wandering back to the original question/problem, the ebrake right now is able to push the shoes out and hold the drum, independent of the hydraulic cylinder. So, that's good! If the ebrake cable needs adjustment, then not being able to retract the brake cable fully could mean that the springs can't pull the shoes back far enough to settle against the wheel cylinder, so that makes sense to me. That or I have the extension link in a slightly or horribly wrong position!  If there's a gap in the rain here today I'll get back into it and see whats up. And assuming that gets sorted, then it'd make sense to bleed/adjust everything and then take another look at ebrake adjustment, no?

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Let me say sorry for getting things off track on your post.. I was curious what the solution was as I have the same situation... I personally don't believe your question was actually answered. So good luck. I hope to see what you do to correct it...

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OK guys, I was just looking at a brake assembly with the question why do I have a gap here with a yellow arrow, I didn't even think about if the brakes needed bleeding or not, as I can do my brakes(new shoes/linings) without having to compromise the hydraulic brake system, therefore I don't need to bleed the brakes.

 

Yes, if you changed the wheel cylinders, once the drums are on both sides and you have adjusted the brakes the first time so they drag slightly, you need to bleed the brakes, once they are bled then final adjustment of the shoes needs to be done, then re-connect the e-brake cable, at least that is how I would do it, but if you need the truck back on the ground because you cannot bleed the brakes for one reason or another, then once the drum is on and you have adjusted the brakes so they just barely drag turning the drum both ways, then re-connect the e-brake cable and adjust it so that it functions properly.

 

Again, I was just addressing the gap between the shoe and wheel cylinder, either the e-brake extension link as the original poster called it was in backwards, or a little while later I came up with the more likely issue/problem, that being the e-brake cable being to tight, which is more likely the actual issue/problem.

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Don't get run over by your truck!?!,

wasn't the first time i've been ran over, probably won't be the last

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Let me say sorry for getting things off track on your post.....

Not a problem, more conversation is ok! The rain just isn't stopping so I doubt I'll get back into it today, much as I'd like to get this sorted. I satisfied myself with buying a can of yellow krylon stained glass paint and a couple other bits I need.

 

One other thing I need to track down is a little hitch pin for the clevis pin that holds the parking brake lever to the shoe on one side. I temporarily put a c clip there but it's not a great fit. I guess I'll be taking things apart again on the brakes so might as well get the right part.

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Are these what your looking for...

20170123_162126_zpspbez4ttj.jpg

 

These are the 2 I replaced with new ones when I did my rear brakes but theres nothing wrong with them not even rusty...

Pm me your address and I will throw them in the mail tomorrow will only cost me a stamp and I got one of those....

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one more thing on my mind about the brakes, is that single reservoir master cylinder. I think I'll copy a ratsun thread from a couple years ago and add a dual cylinder master to the todo list. I'm looking online at a '76 620 master cylinder from centric, mostly because the bleeders are on the opposite side from the clutch master cylinder.

 

If I understand correctly, the different sized wheel cylinders that are already on the front and back drums take care of proportioning brake pressure front/back, so should be fairly straightforward to install? replace the 4 way connector in front with a tee for front left/right, or plug the hole going to the rear and run the other reservoir to the back circuit? And get a proper length pushrod.

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so it turned out the e-brake cable was the cause of my brake shoe problem. I disconnected the cable at the equalizer and the shoes ended up in place, with just a little wiggle room side to side when the wheel cylinder was fully collapsed (this was before I ever pumped the brakes to get fluid into the system). Did my adjustments to the e-brake cable according to the manual, reconnected and then refilled and bled the system. The only thing left not is to adjust the front cable to get the correct amount of stroke on the parking brake, but that's just a turnbuckle. The cable tensioners needed to be adjusted out quite a bit, maybe due to wear of the drums and shoes over the years making it necessary to tighten the cable over time?

 

I also flushed the engine and rad, and tried but failed to get water running through the heater core. The lever under the dash doesn't seem to like to move much, so I'll spend some time on the weekend figuring out what's blocked or stuck there.

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Don't force the lever. If you twist it too hard the soldier joint on the core can split and you'll have to repair it. Which sucks. If it doesn't move try taking the core out and use heat or penetrating oil to break it loose

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one more thing on my mind about the brakes, is that single reservoir master cylinder. I think I'll copy a ratsun thread from a couple years ago and add a dual cylinder master to the todo list. I'm looking online at a '76 620 master cylinder from centric, mostly because the bleeders are on the opposite side from the clutch master cylinder.

 

If I understand correctly, the different sized wheel cylinders that are already on the front and back drums take care of proportioning brake pressure front/back, so should be fairly straightforward to install? replace the 4 way connector in front with a tee for front left/right, or plug the hole going to the rear and run the other reservoir to the back circuit? And get a proper length pushrod.

 

Unless you're going disc brakes, why? More bother than it would be worth on a drum/drum truck.

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Other thing about the master cylinder is the stock single for the 521 is metric and I think the 620 is sae... just something to keep in mind....

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Other way around. 620s are metric.

 

And I think 1972 521s started using the dual master. Everything from then forward was dual resovoir.

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It's actually just the opposite Crash, the 521 series is the end of the SAE trucks, everything went Metric with the 620, I have never checked a 1972 Datsun 620 to see if the body is SAE or metric, but somewhere around 1972/73/74 even the Datsun 620 body is metric.

I do know that earlier 620 wheel brake cylinders can be used on a 521 and earlier because of the way the 521/520/320 hose connects to  the wheel cylinder as I have done it, but other than that not a lot of metric hardware will work on a 521 and earlier except for drivetrain parts, as they are all metric thru all the years.

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Oops... got that backwards.... I knew they were different.... the mix on the 521 has been driving me crazy from day one ....

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Mines a 72 521 and a single master is all that ever seems to come up in searches.. one of my books shows a dual but it may have been an overseas thing. Not at all sure.

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Unless you're going disc brakes, why? More bother than it would be worth on a drum/drum truck.

 

single master means one brake leak and I have no brakes. dual master resolves that issue. I could go disk up front, but seems to me in mostly flat socal, brake fade is less of a worry than just mechanical failure would be. Other than bending some hard brake line, and putting together a right sized push rod for it, seems like an easy mod that increases safety without costing a lot of dough.

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today was my lesson in shit that can go wrong when all I want to do is get water to go through a heater core. I pulled the dash off, removed the gargantuan air conditioning duct that was in the truck (it ran the full width of the dash and made access to everything else a pain in the ass. At the moment, I left it off; the air conditioning is without ducts, and I think I'll try to find something more compact to direct the air.

 

So, AC ducts out of the way, and dash pulled out of the way, I got to he heater core. I undid the little screw that I.must.not.lose, which I lost, and tried to get the valve out. The little brass valve to control heat was stuck but good. I was giving it a twist after soaking in pb blaster, and this happened

 

IMG_0429_zpsrhpe0c9t.jpg

 

Argh..my bad for not being careful enough.

 

I couldn't find a rad place open this afternoon anywhere nearby, so figured that it looks enough like solderable stuff that I'd give it a try. Not like it could get much more screwed up! I got the value housing properly situated in its hole again and cleaned away any old paint or other crap with a small wire brush.

 

IMG_0432_zpsasqto4tb.jpg

 

Soldering worked ok! I used some regular resin-core solder and a bernzomatic torch, and the solder wicked nicely all around the fitting.

 

IMG_0436_zps3kbhv8ib.jpg

 

I was lucky enough to have some other small screws, and found a replacement M2x4mm screw for the valve. Heater core is back in the truck now, and seems so far to be holding water, and I have heat in the cabin. 

 

I did put the old heater hoses back on for now, but they're in lousy condition, so I'll need to find something to replace them.

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You have to be careful with them things, how did you try to remove the valve, by pulling on it with pliers?

I remove them by using a long wood stick in the heater hose end of the tube, I tap lightly.

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You have to be careful with them things, how did you try to remove the valve, by pulling on it with pliers?

I remove them by using a long wood stick in the heater hose end of the tube, I tap lightly.

that would have been a great way of doing it  :P  yeah, I tried to turn the valve with pliers, causing the tube to twist and crack at the joint as you can see. Your approach is much smarter. 

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Just something I learned from Dat521gatherer on here, but it has been so long that I don't even remember which of his threads it was in, something like that should be documented and pinned in a thread by itself so others can find how to do it without screwing up or destroying the core.

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Don't force the lever. If you twist it too hard the soldier joint on the core can split and you'll have to repair it. Which sucks. If it doesn't move try taking the core out and use heat or penetrating oil to break it loose

.

I did the same thing to mine. I used the same process to fix it

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