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CollinMB's RestoMod 521


CollinMB

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On 10/5/2020 at 5:14 PM, thisismatt said:

Check the master cylinder under the dash as that's where you'll find fluid if the master seals failed (mine did this before).  Easy check before you start pulling all the wheels & drums off

On the early trucks (pre dual circuit master) the lack of a residual valve means that when it sits for a long time, the seals in the wheel cylinders tend to shrink away from the piston, allowing air in and fluid out. Sometimes the air just comes in, along with moisture, and allows corrosion to begin inside the cylinder. The buildup of corrosion then gets in the way of the seal and it starts a drip there.

 

You can usually just disassemble the wheel cylinder, clean it and hone it and put it back together, but I would also consider installing a 2# residual valve to keep those lip seals engaged.

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The early 521 trucks have residual valves as I put my 1969 Datsun 521 kingcab onto a 1981 chassis/frame and used my stock 521 master brake cylinder on a Ford Courier booster, I made it maybe 10 blocks out and could feel the brakes dragging, I turned around and made it 7 blocks back before I sheared the drive line bolts off between the transmission and transfer case(was a 4wd at first), I ran to my friends house and asked him if he would tow me home, I ran home and got a 10mm wrench, we hooked up the rope, I opened one of the caliper bleeders and let the pressure off the brakes(front and back because single circuit), and he towed me home.

I then fixed the drive line bolts and gutted the residual valve(rubber piece and spring) out of the master brake cylinder and it worked fine after that.

I also had to do the same thing to my 1971 Datsun 521 work truck with front disc brakes(1990 dual piston V6 hardbody calipers) when I had a brake master go bad after a decade of driving it that way, the old ones residual valve appeared did not work properly, but the new one worked, soon after(couple years) I converted over to power brakes/dual circuit master and after doing that I thought I should have done this 15 years ago(insert face palm here), it literally stopped the truck 10 times better, before I had my foot hard into the pedal especially when towing my work trailer(it had electric brakes), afterwards it was like I wasn't towing a trailer.

1 hour ago, Stoffregen Motorsports said:

On the early trucks (pre dual circuit master) the lack of a residual valve means that when it sits for a long time, the seals in the wheel cylinders tend to shrink away from the piston, allowing air in and fluid out. Sometimes the air just comes in, along with moisture, and allows corrosion to begin inside the cylinder. The buildup of corrosion then gets in the way of the seal and it starts a drip there.

 

You can usually just disassemble the wheel cylinder, clean it and hone it and put it back together, but I would also consider installing a 2# residual valve to keep those lip seals engaged.

 

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Got everything from the donor Miata into the truck:

 

1802bCN.jpg

 

That's how swaps work, right?

 

Everything is broken down so I can start cleaning some pieces to throw into storage and/or determine what will be going up for sale since a number of items won't be needed for my build plans.

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  • 1 month later...

So I've been driving the truck about once a week lately back and forth to work. This Wednesday the truck started breaking up under acceleration and would cut out. Today I ended up driving it and the problem got worse, power cuts and started bucking and then it died. Waited a few minutes and it started back up. Drove a couple more miles and it died again. This time it wouldn't start back up. I'm suspecting that the plugs might be fouled out because it runs rich and I'm hoping it's not something worse. Anyone else run into similar issues?

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Hard acceleration or long steep hills causing the engine to sputter and die may be due to a lack of fuel delivery. My roadster used to do the same thing because the rusty gas tank used to fill the fuel filter with sediment. The worst part was that the fuel filter (clear plastic) always looked fine, but the inner filter was filled up with rust. 

 

Might be worth checking.

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4 hours ago, mainer311 said:

Hard acceleration or long steep hills causing the engine to sputter and die may be due to a lack of fuel delivery. My roadster used to do the same thing because the rusty gas tank used to fill the fuel filter with sediment. The worst part was that the fuel filter (clear plastic) always looked fine, but the inner filter was filled up with rust. 

 

Might be worth checking.

I pulled the plugs during my lunch break and they were super dirty. I think the timing probably needs to be adjusted. I probably also need to check the piston rings, but I don't think I'm committed enough to digging that deeply into the engine for the time being

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  • 1 month later...

Couple of updates:

 

worked on cleaning up the engine bay by reclocking the fuel pump to have a better configuration, as well as moved the battery to the bed:

8wR8LPq.jpg

 

cOnps9F.jpg

 

Finally picked up a hub to install my Nardi and QR as well:

trdclGU.jpg

 

FVtPHvf.jpg

 

My horn never worked since I've owned the truck, so I'll be doing some wire testing to track down the why they're not working.

 

One last piece, I got crafty with my 3D printer and designed a phone mount:

KufVds8.jpg

 

Only other plans for now, I'm planning on getting the truck prepped to weld in the new rocker panel.

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Update on the horns. Checked all the wiring and remembered I bought a new relay. Got that installed and we're all good. Just needed to order some new blade connectors and once that's all sorted it'll be wrapped up. Felt inspired to get more electrical figured out and found why my hazards were only working on one side. Turns out the plug was missing a pin. Jumped it into my new harness and all four lights are working.

At this point, the only thing in the electrical system that doesn't work is the reverse switch, which I suspect is due to the worn out components in the transmission not fully compressing it as it works when compressed manually.

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1 hour ago, CollinMB said:


At this point, the only thing in the electrical system that doesn't work is the reverse switch, which I suspect is due to the worn out components in the transmission not fully compressing it as it works when compressed manually.

 

Hmmmmmm not to say internal parts won't wear, but think it's pretty rare!  Is the reverse switch NEW?  They are typical cheap Datsun switches, which do wear out, get gummed up inside etc etc.  If the switch is a simple "plunger/pin style", pretty sure there is simply a "divet" in the internal shift shaft that "trips" the plunger/pin as the shaft slides the gear into place, thus turning the reverse lights on.  Pull it out of gear,  the switch turns off.   My guess is electrical, not mechanical............

 

When converting an automatic 510 to manual, the auto wiring harness does not have a separate reverse light switch wiring, as the reverse light switching was part of the neutral safety switch.  That said, you have to wire up a reverse light switch circuit to make it work.  Funny, I don't even know if they offered an automatic 521...............they did with the 620!

Edited by yenpit
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Yes, the switch is new. I've tested it plugged in and compressing it manually and it works fine. I don't think the contact point in the transmission is making full engagement as there is quite a bit of play in it. I might look at getting a rebuild kit and see if that solves some of the issues.

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Quite a bit of play in what? The transmission switches are activated by depressions ground into the shift shafts and those shafts are very hard. Not likely a shaft would ever wear out, or even the bore in the transmission case that the shift shaft rides in.

 

Are you sure you have the switch in the correct location? Some transmissions had multiple switches. Also, some of these switches work differently. Some are on always on then get switched off, some are always off then switched on.

 

Could it also be that you have too many washers or too thick a washer on the switch threads? Do you have a pic of the switch and/or where it plugs into the transmission case?

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I have one of each of the switches. When I bought the truck it had the wrong kind of switch installed so the reverse lights were always on. I swapped it out for the correct type, but if it's in the right location, not so sure. I wasn't super worried about it when I swapped it as long as the light wasn't on all the time. I'll probably have to do more research, maybe bust out the Haynes.

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I have also read the if the front bellhousing has been swapped/replaced, there are at least two different positions for the reverse switch.......the internal shift shaft matches the bellhousing, so if you swap a bellhousing, the switch position might not match the shift shaft “detent”!!  Pull the switch, look into the hole, have somebody move the shift lever in & out of reverse, look for the “detent” in the shift shaft. No detent, that’s yer issue! 😬🤔 

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I checked over the weekend, the switch is in the right location. As I said previously, it works when compressed by hand. Not sure why it's not engaging, but I also don't think it's too big of a deal considering I'll be eventually swapping everything anyways.

 

Hopefully I'll be replacing my rusted out rocker this coming weekend. Other than that, it'll most be small maintenance type stuff up until I do the drivetrain swap. Might throw on some blocks and lower the truck in the meantime for shits and giggles.

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  • 3 weeks later...

So the rocker weld job didn't go as plan due to it being the wrong one -_-. For the record, it came with the truck, I didn't buy it.

 

In other news, I dug myself into a new hole last night:
nrhbqjW.jpg

 

Only snapped two 50 y/o bolts as well! I started pulling the front apart to eventually go through, prep, and recoat the wheel wells/inside of the fenders. Whoever did the undercoat the first time did an absolute shit job with no prep, evidence by it flaking off. I'll be using some Boom Mat spray and rust converter, as well as so flat black paint on the mating surfaces to prevent gaps. I'll also be working through drilling out all the old bolt/screw holes and replacing them with rivnuts.

 

So a lot of these jobs I was planning to wait until I start the swap, but the biggest issue I have is no garage/shop space. So, I'll be working on more resto jobs to potentially sell the truck, buy/build a shop, and then subsequently buy another truck to do my build with.

 

I'm not necessarily set on selling, but if the right offer comes along, I will let it go.

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  • 2 weeks later...

Well, this thing happened:

b0tuKi3.jpg

 

One of the biggest hurdles I was running into was finding a new engine that wasn't going to bankrupt me. When this one popped up with a trans for the low low price of free.99 I couldn't pass it up. The P.O. said it needs a rebuild, but it's still a lot cheaper than trying to buy a mystery motor. 

 

So the plan now is to move forward with pulling and selling the engine and trans currently in the truck.

 

As for the truck itself, it looks like this at the moment:

NQHEM3X.jpg

 

Got both fenders off, front bumper, and front valance. Had a buddy come over and power wash the grime off in preparation of undercoating.

 

For now, I'm going to work on doing some touch up, but other than that I'm planning to get a welder in April, and then I can get to work on some of the major changes.

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