Disc Brake Conversion on 71 521

[Charlie69]

If you want cheap buy Beebani's.  If you want quality and extras buy Mike Klotz's.  Personally I purchased Mike's kit.  Very pleased with the quality and fit.

[MK4A80]

Hey guys,

 

So i think im going with beebani kit.

Found his kit on ebay: https://www.ebay.ca/itm/Front-REAR-BRAKE-CONVERSION-FOR-DATSUN-PICKUP-/192794685783?oid=192756005281

 

One thing with his kit can i still retain the ebrake, its kind of a must.

I live in a hill and dont want my truck to go rolling away.

 

Thanks for the input.

 

 

Fredy.

[MK4A80]

On 12/18/2018 at 2:41 PM, Tucson620 said:

This.  Also, any pics of the surgery?

 

For what it's worth, I installed mklotz's kit on my truck plus a Wilwood manual proportioning valve. None of this NLSV witchcraft, and left rears as drums. Very happy with results and braking is much less an adventure now. Do your research and get a beebani or mklotz kit, some junkyard parts, and new or reman shiny parts.

 

Here I've had the boy load up telephone poles, then headed for steepest downhill!

 

Its heal now, so it wont show much.

 

But my surgery was for my fistula, it got redone as it was having cleaning issues.

 

If you don't know what a fistula is, its basically a vein and artery connected together so it can be access (via needles) to

run on dialysis machine.

 

Nice truck though!

 

[Alexp521]

Well I bought mine from beebani  I’m installing them at the moment so far no problem other than the lines are different and I can’t finde the  inner seals or outer if some one has a part number that wood be a big help

[G-Duax]

10 minutes ago, Alexp521 said:

 if some one has a part number that would be a big help

 

There, fixed.

[pidge]

On 9/18/2019 at 6:58 PM, Alexp521 said:

Well I bought mine from beebani  I’m installing them at the moment so far no problem other than the lines are different and I can’t finde the  inner seals or outer if some one has a part number that wood be a big help

Hey Alex did you eventually finish your Beenbani front disc install? Any pics, tips or eye openers? If you finished how do you like it? 

-Pidge  

[d.p]

10 hours ago, pidge said:

Hey Alex did you eventually finish your Beenbani front disc install? Any pics, tips or eye openers? If you finished how do you like it? 

-Pidge  

 

Its super simple man...one thing I ran into was the copper crush washers that came with the calipers I got from Rock Auto were wrong and leaked.  Took me a while to figure that out so make sure you get the right size ones if you go the RA route.  

[mainer311]

If you use the OEM D21 front rubber brake hoses, you have to finagle them a little bit to figure out the best routing. There's a bend in one of the ends that works better if it's pointed in a certain direction. If i had to do it again, I would just get custom stainless lines made with a bulkhead on one end, and a banjo on the other. The 521 uses 3/8-24 threads on all brake fittings. The stock D21 calipers are M10x1.0. Keep that in mind, since you'll need to crossover at some point. Pegasus racing is a great website to have custom hoses made, with a plethora of different fitting styles.

 

As mentioned elsewhere, buy a dual reservoir master cylinder and split the front brake circuit from the rear. Late model 620 master cylinders had disk in the front and drum in the rear, so the MC's were already setup with the correct residual pressure valves. Use one of those.

 

Edited January 7, 2020 by mainer311

[Zonargx]

Him I’m new here And I have a 1971 521 pick up. I am looking to install front disk brakes on it for better braking. I understand the whole concept of installing them with a bracket using d21 calipers brakes and using the the proper rotors as well as the brake lines. What I really need help with is what am I gonna to do about the master cylinder? Do I just have to install a dual master and a brake booster or just the master and what booster do I need? 
 

thanks

[mainer311]

19 hours ago, Zonargx said:

Him I’m new here And I have a 1971 521 pick up. I am looking to install front disk brakes on it for better braking. I understand the whole concept of installing them with a bracket using d21 calipers brakes and using the the proper rotors as well as the brake lines. What I really need help with is what am I gonna to do about the master cylinder? Do I just have to install a dual master and a brake booster or just the master and what booster do I need? 
 

thanks

Your best bet is to run a dual-reservoir master that has residual valves already setup for a truck with discs in the front and drums in the rear. Then split the front brake circuit from the rear brake circuit at the junction that is bolted to the firewall. You don’t really need a booster. Upgrading to discs will give you plenty of stopping power vs. the original drums.

 

Get a master cylinder for a late 70’s Datsun 620.

Edited June 21, 2020 by mainer311

[Zonargx]

59 minutes ago, mainer311 said:

Your best bet is to run a dual-reservoir master that has residual valves already setup for a truck with discs in the front and drums in the rear. Then split the front brake circuit from the rear brake circuit at the junction that is bolted to the firewall. You don’t really need a booster. Upgrading to discs will give you plenty of stopping power vs. the original drums.

 

Get a master cylinder for a late 70’s Datsun 620.

Thanks Mainer!!! I also have another question about where the carbs vacuum goes to.I lookEd at my carb and it looks like it had a spot where it would go but it seems like it has the nipple broken. I can post pictures later. I am not and expert on this Datsun I just bought it a week ago I know a little more than he basic mechanics but I’m not familiar with datsuns.

[mainer311]

Post a pic. The only thing that uses vacuum from the carb on a 71 521 is the vacuum advance on the distributor.

[Zonargx]

Sorry I found a picture of a carb for sale on eBay that’s the same as mine and I I did see the vacuum nipple that for the distributors and the one I have is missing it. It actually looks like it’s broken off at the bottom

[DanielC]

There is also a port on the top of number 3 and 4 intake manifold runner, tapped 1/4 British Pipe threads.  This port on a stock 521 was used to signal the glup valve that diverted a quick burst of air into the intake manifold from the exhaust air injection pump.

Some 620 trucks eliminated the air injection into the exhaust, and also got power brakes.  This same port on the 3-4 intake manifold runner then was used for vacuum to the power brake booster.

[Zonargx]

On 6/20/2020 at 7:21 PM, mainer311 said:

Your best bet is to run a dual-reservoir master that has residual valves already setup for a truck with discs in the front and drums in the rear. Then split the front brake circuit from the rear brake circuit at the junction that is bolted to the firewall. You don’t really need a booster. Upgrading to discs will give you plenty of stopping power vs. the original drums.

 

Get a master cylinder for a late 70’s Datsun 620.

Yo Mainer I’m waiting on beebanis kit to arrive I’m also ordering the needed parts as well as the d21 brake lines do you know what fitting I need to get to run those hoses to the 521 brake lines and also could I just remove the rear from that junction block it and make a hose and run it to the dual master instead? Or just the fronts be removed, block those ports in the junction. Join those two hoses and run them to the master. Or remove all have the rears have a proportion valve , join the front lines and run them to the master ? I want to do the most basic set up for now that does not requires to much work.

[Zonargx]

can I just use the original front brake hoses From the 521 and run a banjo set up?

[Zonargx]

@Charlie69 you have any ideas on a easy cheap set up to run the front disk brakes with the beebanie d21 kit? I know I was just asking Mainer but maybe some of you who have been here longer also know

 

thanks

[Charlie69]

I use the Mike Klotz disc brake kits.  I am familiar with Beebanis' kits in only helping other people modify them to fit.  Not sure what parts his kits take.

[mainer311]

13 hours ago, Zonargx said:

Yo Mainer I’m waiting on beebanis kit to arrive I’m also ordering the needed parts as well as the d21 brake lines do you know what fitting I need to get to run those hoses to the 521 brake lines and also could I just remove the rear from that junction block it and make a hose and run it to the dual master instead? Or just the fronts be removed, block those ports in the junction. Join those two hoses and run them to the master. Or remove all have the rears have a proportion valve , join the front lines and run them to the master ? I want to do the most basic set up for now that does not requires to much work.

 

The easiest thing to do is to remove the rear line from the junction block, then make a hard line that runs from the removed rear line to the rear output on the MC. (You'll need a female-female coupler.)  Then use a plug to plug up the hole in the junction block. Leave the entire front circuit as-is. The junction block is tapped 3/8-24, so get a plug that is that size. You can use a really short bolt with a copper washer on it. 

 

To use the D21 front hoses, you'll need to cut the 3/8-24 tube nuts off of the ends of the front hard lines, and then re-flare the tubes after switching to M10x1.0 tube nuts. I found it easier to just remake the entire front lines.

 

Here's a picture of how I have it setup:

[Zonargx]

1 hour ago, mainer311 said:

 

The easiest thing to do is to remove the rear line from the junction block, then make a hard line that runs from the removed rear line to the rear output on the MC. (You'll need a female-female coupler.)  Then use a plug to plug up the hole in the junction block. Leave the entire front circuit as-is. The junction block is tapped 3/8-24, so get a plug that is that size. You can use a really short bolt with a copper washer on it. 

 

To use the D21 front hoses, you'll need to cut the 3/8-24 tube nuts off of the ends of the front hard lines, and then re-flare the tubes after switching to M10x1.0 tube nuts. I found it easier to just remake the entire front lines.

 

Here's a picture of how I have it setup:

Perfect that’s exactly what I had in mind to do but wasn't sure if it was gonna be a problem or not but I guess that junction is just to split the hose to the front and rear not like and actually valve right?.. anyways thanks a lot I guess that has answer all my questions. I’ll have to post my i imagines on photobucket to have them posted right? So I can show my install later on once I get it done

[mainer311]

Don’t use photobucket. Use Imgur or something. That’s what I use. It’s easy and free, and you don’t have to make any of your pictures public.

[Zonargx]

Does anyone know if there’s a topic about the evap canister on the 521s that’s located on the bed of the truck left side of the wheel well?

[bilzbobaggins]

10 minutes ago, Zonargx said:

Does anyone know if there’s a topic about the evap canister on the 521s that’s located on the bed of the truck left side of the wheel well?

 

There are a few.

 

Easiest way to search this site is as follows.  Go to google.  In the search box type  "ratsun" followed by what you want to search

 

"ratsun" 521 evap canister  I just ran that one and got lots of hits.

[thisismatt]

site:ratsun.net <search terms> is the most direct way

 

[DanielC]

The tank in the bed of 521 trucks is not a charcoal cannister.  It is just a vapor and liquid separator.

There is a valve on the left inner fender, close to the carburetor, with three ports.  One port goes to the air cleaner, one port goes to the bed separator tank, and the third port goes to a small pipe on the PCV pipe from the crankcase.  "A" on the valve goes to the Air cleaner.  "F" on the valve goes to the bed separator tank, "C" on the valve goes to the Crankcase.

Clean air can flow from the air cleaner into the gas tank, through the vapor separator.  this allows air into the gas tank as gas is used up.  Gas vapors cannot flow from the fuel tank or the vapor separator tank into the air cleaner, they are allowed by the valve to go to the crankcase, where they are stored.  When the engine is running, the crankcase is purged by the PCV system.