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Re: The Adventure Begins- My 620 build thread

Posted: Mon Aug 22, 2022 2:25 pm
by AZhitman
Yep. Carl is correct.

I'm so glad I spent 6 months and countless dollars scanning these manuals... :D

https://www.nicoclub.com/service-manual ... Manual.pdf

See pages BR-13 through 15.

Re: The Adventure Begins- My 620 build thread

Posted: Mon Aug 22, 2022 5:07 pm
by Randalla
Carl, I'll double check the manuals Greg posted the link to. The Haynes manual says the longer and thinner of the two springs goes on top and the other one goes on the bottom, which is what my pictures showed (Haynes may be wrong though :lol: ). The real problem seems to be there are no holes in the shoes for the kind of springs I have. If the springs had a hook on the end I could probably use the triangular holes at the edge of the shoes, and they'd stay in place. Looks like there are two different versions of the two springs for the shoes. The version I have have an "S" shape on each end and that version goes into holes on the two shoes. The other spring version is what I need, the ones with a hook or a U on each end that would hook into the triangular cut outs on each shoe.

Re: The Adventure Begins- My 620 build thread

Posted: Mon Aug 22, 2022 5:26 pm
by Randalla
Today, I was able to get the leak at the thermostat housing stopped after re-gasketing and sealing the threads. I also got my spare steel wheel refinished and had a new tire mounted at Discount Tire. After I cranked the wheel back into place under the pickup bed, I decided to re-do the rear half of my exhaust job, to mount the muffler ahead of the resonator. With the spare in place it seemed like a more logical way to assemble the system, given space considerations. I've decided to wait and have the tail pipe and resonator welded on by the muffler shop.

I've been curious to see what a compression test would show since I really know nothing about this motor. I was really pleased to see the following numbers, after averaging two tests.

Cylinder #1- 163 pounds
Cylinder #2- 176 pounds
Cylinder #3- 163 pounds
Cylinder #4- 170 pounds

In addition to the top end of the motor looking so clean under the valve cover, I now know the internals are in relatively good condition as well, which is a relief.

Re: The Adventure Begins- My 620 build thread

Posted: Tue Aug 23, 2022 5:17 pm
by AZhitman
What's weird is the hole issue. That part # from Centric shows holes: https://www.amazon.com/Centric-Parts-11 ... B000TXY586

Here's these, if you think they'd help (but I don't think they will): https://www.ebay.com/itm/222744354409

Is the center support rib of the shoe in the dead-center of the shoe friction material? Or is there a shallow side and a deep side?

Re: The Adventure Begins- My 620 build thread

Posted: Tue Aug 23, 2022 5:24 pm
by AZhitman
Reference pics.
1975-datsun-620-lil-hustler-pickup-9.jpg
37ce0f95767d44167211c81af256fdf4.jpg

Re: The Adventure Begins- My 620 build thread

Posted: Tue Aug 23, 2022 7:03 pm
by Randalla
Greg, I've now been able to determine there are different springs for different shoes. The photo you attached of the springs selling on eBay, show versions for both types of shoes. The white and black springs are the ones that fit the shoes I have on the rear. The other long springs are for the shoes with the holes, like shown in the other photo you posted. Comparing the photos of all the brake shoes on Rock Auto's site, it does appear that all the front shoes have the round holes in the proper place, and all the rear shoes have the triangular cut outs. I don't know if the front/rear shoes are different in other ways as well. Regarding the center rib you referenced, the rear shoes can only go on one way in the rear because they must accommodate the parking brake lever and spreader bar, where the shoes are notched.

Today was my day for straightening/pounding and rubbing out both front fenders. I've got the driver's side 90% done (rest will get done tomorrow) and the passenger side about 50% (it was a mess, the worst panel on the truck). Challenging work but rewarding seeing improvements.

Re: The Adventure Begins- My 620 build thread

Posted: Wed Aug 24, 2022 5:48 pm
by Randalla
Test fitted the driver's fender, grille and bumper today. It's finally beginning to look like a truck again. With Ron's help we were able to bleed the clutch master, slave cylinder, and shift through all the gears with the engine running and the back end off the ground. Everything seems to be working so far. Even discovered in the process that the fuel sending unit and gauge are talking to each other. Tomorrow I'll be running out to Birdman's house to hopefully retrieve some necessary rear brake parts. The only thing at this point preventing a brief trip down the street is functioning brakes.

Re: The Adventure Begins- My 620 build thread

Posted: Thu Aug 25, 2022 7:55 am
by Duffman
Looks great, Randy!!

Re: The Adventure Begins- My 620 build thread

Posted: Fri Aug 26, 2022 10:34 pm
by Randalla
Thanks to Birdman for the donation from his 620 pickup trailer yesterday and his help removing them. I was able to gather all the brake hardware I needed and shoot photo reference for rebuilding my rear brakes. Today, I got all the parts cleaned and installed (with new drums), though it was like a Chinese jigsaw puzzle. I learned a lot in the process. All four of the long springs for doing both front and rear drum brakes have different part numbers. The front ones are still available, but the rears are unobtanium, unless you're fortunate enough to find used ones. The front springs have the "s" bend at the end, while the rear springs are hooked. There's no way to substitute one for the other on a 620. The copper colored shims for retaining the brake adjusters are still available but the brake adjusters themselves are not.

Re: The Adventure Begins- My 620 build thread

Posted: Wed Aug 31, 2022 8:10 pm
by Randalla
Bled the clutch slave and master, as well as the brake master and wheel cylinders with Ron's able assistance. Unfortunately, though we were able to bleed all the air out of each system, we couldn't get a hard pedal in either case. I broke down Monday and ordered new master cylinders, as I believe the rubber seals are badly deteriorated, given all the black muck in the bottom of the reservoirs. The brake master came today and the clutch will be here tomorrow. Plan to have both installed by the weekend

I spent today fabricating outside mirrors for the truck. The plastic ones that came on the truck were trashed and so were the brackets. It's clear from all the holes in both doors that the truck had a series of mirrors on it over the years. I didn't want to drill any more holes, preferring to use the holes I had and fabricating brackets to match. I found the new steel mirrors themselves on Amazon. Finished installing one today and will do the passenger side tomorrow.