Are these interchangeable?

[Zak's Z]

I pulled off the front and rear suspension this weekend so I can clean it up, send it in to get the bushings changed out, and replace anything that needs it. I have a set of brand new rear wheel cylinders in a box. The ones I have look ALMOST the same as the ones on there. The ones I have have a 'pointed' rubber surround and the line goes into the top. The ones that are on the car the rubber surround is 'rounded' and the lines go in the side.

I included some pics. My question is, are these interchangeable? I need to replace one of mine, its all seized up and rusty. If they aren't can I make them work or change some parts from the good one?

[geezer]

Who is the manufacturer of the new set in the box? You may have to cross reference the part numbers to see if they are compatible. I don't see a problem if the bore size is the same, brake cable fits up and you can fasten the brake lines.

Edited May 25, 2009 by geezer

[Carl Beck]

If the part numbers on the box - end with N3001 then they are for a 1973 Model Year car {10/72 forward}. To use them you would need to get the hard brake line for the 73 Model Year for the back of the drum...

FWIW,

Carl B.

[Zak's Z]

Thanks Carl and Ron. I dont have a box with part number, they were in a bigger box of stuff. Heres a pic. All they say on them is 7/8 and Tockico (theres an 'E2' stamped on one and a "01J" on the other)

The red arrow is where the brake line goes in this new cylinder. The black arrow is where it goes on my old one on the car.

I cut the hard line and the rubber line as I plan on replacing them both, the hard line that was on there was just kind of made to fit, it does not look like a pre-formed hard line as it was kinda wrapped around everywhere. What does a '73 hard line look like? does it go around the mount for the control arm or up thru that mount?

Edited May 25, 2009 by Zak's Z

[Walter Moore]

I originally used some "scrounged" wheel cylinders on my car when I first got it running, but with very little luck. The primary difference between the various years is that the early wheel cylinders slide back an forth in the backing plate during operation, and the angle of the threaded hole for the flair fitting is different. I believe that the correct wheel cylinder for a 71 has the hole at an angle, but I am not sure about the 73.

Because the wheel cylinder slides during operation, the hard steel line that connects it to the brake hose is formed in a long arc that basically follows the outline of the backing plate around. It needs that long path to allow the tubing to flex during braking. It doesn't move much at any one time, but it shifts as the shoes wear I think. The wheel cylinder is single sided, and to move the opposite shoe the whole cylinder has to slide in the backing plate.

I messed around with my scavenged parts for a year, never really got them to work, then gave up and replaced EVERYTHING on both sides, Drums, shoes, wheel cylinders, etc with Nissan parts from a dealer. After I did that the rear brakes work reasonably well.

I have done brake work on a lot of cars with rear drums, and the Z has the strangest drum brake setup I have ever seen. It works well when everything is perfect, but it does not tolerate improvisation well...

My advice: Get the right parts to start with and save your self a lot of trouble.

[Zak's Z]

Thanks Walter, I'm trying to see if the parts are interchangeable. Various sites list the cylinders I have (the new ones) as 70-78. One or two places have 71-72 then 73-78. The 71-72 does have the hole at an angle, the other differences I cant see.

The extra parts I have aren't scavenged, they are new cylinders. and at about $200CAD for new ones, I'd really like to use these if they will work.

[Nigel1943]

Thanks Carl and Ron. I dont have a box with part number' date=' they were in a bigger box of stuff. Heres a pic. All they say on them is 7/8 and Tockico (theres an 'E2' stamped on one and a "01J" on the other)

The red arrow is where the brake line goes in this new cylinder. The black arrow is where it goes on my old one on the car.

I cut the hard line and the rubber line as I plan on replacing them both, the hard line that was on there was just kind of made to fit, it does not look like a pre-formed hard line as it was kinda wrapped around everywhere. What does a '73 hard line look like? does it go around the mount for the control arm or up thru that mount?[/quote']

Only problem I can see is that you have 2 right hand cylinders. They are handed L & R.

[Carl Beck]

What does a '73 hard line look like? does it go around the mount for the control arm or up thru that mount?

Hi Zak:

The hard line for the 73 is pre-formed, and it is made to fit the inlet on the 73 wheel cylinder. Off hand, I can't remember the routing of the hard line... I do know that some time ago the 70/72 rear wheel cylinders were NLA - and the only way to get replacements was to use the 73 wheel cylinders with the 73 hard lines.

Seems to me that the last time I tried to order the hard lines one or the other side for 73 was NLA also...

FWIW,

Carl B.

[Zak's Z]

Thanks again guys, I took these in to the local Datsun mechanic today and he said at first I had 2 right hand cylinders due to the R stamped on them. But the are mirror images of each other and after some debate between mechanics it seems they are L and R, but one has an inverted R lever. Worst case I re-use the L lever from my old ones.

They said they can bend me some hard lines for them also.

Now I need to get ball joints, tie rod ends, half shaft u-joints and wheel bearings while the bushings are being changed. This car will be ready any month now....

[hogie]

I just replaced my right cylinder with an Oreilly/brakeware part that looks exactly like yours last night. Everything fit fine and slides just the way it should.

My brake lines were crap in the first place so I used a 20" japanese line from Autozone. It is a bit longer than factory, but still fits just behind the backing plate without any sort of interference.

For some odd reason the left cylinder isnt available from my local parts houses...so I just rebuilt it. The kit looked exactly like it was made for teh new replacement cylinder. However it had the same bore and seemed to fit fine.