320 clutch slave

[Crusty320]

So I recently caved and brought my truck in to a local shop and there’s a couple a big things that need fixing before I drive it 1, the wheel bearings need a repack and 2,the clutch master cylinder and slave are leaking and that’s what I need help with I’ve read in some older posts that a 521 master should work just have to switch out the rods which is what I did with my brake master clylinder. The thing I can’t figure out is where to get a slave for it. I haven’t been able to find anything expect places that could “repair” it while that is always a option I’m on a big time crunch and need this done by early June. Keep in mind I don’t have the biggest budget and would love some help sourcing a slave cylinder. 
thanks

[datzenmike]

The places that 'repair it' probably have access to a seal kit, hell you can replace then yourself with a kit. I've done slaves and masters.

[Crashtd420]

I thought the later slave can also be used.... I remember hearing or reading it... I belive the mounting holes need to be opened up by slotting them or something...  

 

 

[datzenmike]

My fu only goes back to the mid '60s Patrol and the 520/521 and Roadster. The further back the less info there is.

[Crusty320]

21 hours ago, datzenmike said:

The places that 'repair it' probably have access to a seal kit, hell you can replace then yourself with a kit. I've done slaves and masters.

So I can probably just buy a seal kit form Napa or something and do it my self? Appreciate the help.

[Stoffregen Motorsports]

I'm pretty sure the clutch slave is of the BMC variety. Yet another holdover from the MG/Austin era. If so, any Austin Healey Sprite clutch slave ought to work.

https://bpnorthwest.com/austin-healey/clutch-slave-cylinder-1275-sprite-and-midget/?gad_source=1&gclid=CjwKCAjwupGyBhBBEiwA0UcqaGMNwXTt-HGKSsYiHjRQzrZkc6qqiSyVNDDbZg-89YUZ5LEPhuHXMBoCwmwQAvD_BwE

 

 

That said, I use this aluminum slave from Speedway on my Sprite. It's the same dimensions as the OEM BMC unit, if you can get past the color - https://www.speedwaymotors.com/Speedway-Push-Type-Clutch-Release-Slave-Cylinder,1944.html?utm_medium=CSEGoogle&utm_source=CSE&utm_campaign=CSEGOOGLE&gad_source=1&gclid=CjwKCAjwupGyBhBBEiwA0UcqaMfRyzkLreUqV4InG8k2AMteZxjvvbsLj-TIYFI5yriDd9nz-st3FhoCq5wQAvD_BwE

 

 

Edited May 15 by Stoffregen Motorsports

[datsunerik]

I have found that datsun-roadster-parts.com has some early hydraulic stuff in inventory.

I've had fast shipping and good prices.

And if yoy get new stuff and want to get rid of the old stuff please let me know.

I'm also looking for a fuse box for a 320 if anyone knows of a good used one!

Erik

[datzenmike]

Welcome to classic car ownership. There are those that will only keep their Datsuns a matching numbers car and only original Japanese parts. Next down the scale are those that cannot find original parts and replace with used parts or rebuild them. Then there's substitution of a similar Datsun part, perhaps modify it, then a part from another car maker. Last is making the part yourself. Over all of these there is often a part that's available that offers extra safety such as changing from single to dual brake master cylinders or reliability such as an EI distributor.

[wayno]

If I needed to get the truck moving and you have already replaced the clutch master with one from a 521 then I would buy a 720 clutch master likely available locally and slot the mount holes. actually I would likely cut from the outside on both sides opening the hole completely, I would do it with a cutting disc on my Dewalt angle grinder, but a hacksaw could be used to do this, then I would center the slave to the clutch arm and tighten the mount bolts down, make a rod for it, bleed it and call it good.

 

There possibly might be an issue though, how is the rod connected to clutch arm, if it has a pin holding it on the clutch arm then I would likely make a new arm the right length from scratch, this is something I can do, not sure about you maybe the stock arm will work.

[datsunerik]

Thats a lot of work when you could buy the correct one for about $100.00 and be done with it. White Post and Apple Hydraulics can rebuild it for a little more and have a long warranty.

I've seen the slot version make the clutch arm bind and need more foot pressure to push in the clutch. 

I totally understand wanting to get it on the road fast but safety needs to be factored in as well.

Just my 2 cents.

[datzenmike]

I rebuilt the one in my '78 620, the kit was $12 Canadian. Took maybe 20 min.

 

I can't figure out the difference between the ones with or without the external return spring. Both have a spring inside pushing outward behind the piston. The 521 is quite large so it needs the larger external spring to keep it compressed inside. The later ones have a tiny spring. The seals are virtually the same.

[Stoffregen Motorsports]

1 hour ago, datzenmike said:

I rebuilt the one in my '78 620, the kit was $12 Canadian. Took maybe 20 min.

 

I can't figure out the difference between the ones with or without the external return spring. Both have a spring inside pushing outward behind the piston. The 521 is quite large so it needs the larger external spring to keep it compressed inside. The later ones have a tiny spring. The seals are virtually the same.

It must have something to do with the placement of the fluid feed hole, right? What else could be different?

 

I prefer using a slave with a spring. It keeps the throwout bearing from resting on the pressure plate all the time.

[datzenmike]

The arms are the same but for the hole. The arms clip onto the ball pivot using a spring? That sort of pulls the arm back and centers it in the transmission hole.

 

I also slip into neutral coming up to stops and let the clutch out. Saves the strain on the release bearing waiting for the light to turn and the thrust bearing on the crank when oil pressure is lowest at idle.

[difrangia]

If your cylinder is not too pitted, you might check into this:

 

https://www.ebay.com/itm/271528010535

 

I rebuilt mine with a kit like this and it's been hammering-down perfectly for eight years. BTW, the cylinder for the floor-shift and column-shift slave is the same except for the op-rod.

 

Edited May 17 by difrangia

[Crusty320]

On 5/17/2024 at 5:08 AM, difrangia said:

If your cylinder is not too pitted, you might check into this:

 

https://www.ebay.com/itm/271528010535

 

I rebuilt mine with a kit like this and it's been hammering-down perfectly for eight years. BTW, the cylinder for the floor-shift and column-shift slave is the same except for the op-rod.

 

Picked this up a few weeks ago and worked perfectly appreciate it.