Clutch Damper Options

[DIY 1985]

Is it possible to get a new clutch damper?  If not, is the fitting 10mm?  Where do I get the delete / bypass fitting?

Can I still get OEM master cylinder, slave cylinder, and soft line for the clutch on a 2wd '85?  What are the part #s?  If not what are the better ones to buy? 

What should I use, a particular pressure or vacuum bleeder, or an old beer bottle?  I am doing this one solo.

[datzenmike]

You can by-pass it probably with a junction fitting?

 

Auto supply or parts stores still have the master and slave for the 720 ... around $20 CDN. But these days they are cheaply made. My last slave I took apart and made sure there was no debris left inside and the rubber seal was seated properly and intact. I also wet it with hydraulic fluid so it wouldn't start off dry. Just insurance.

 

I find a couple of pumps and the weight of the fluid will siphon down hill and push the air out of the bleeder on the slave. Way easier than doing the brakes.r

[Stoffregen Motorsports]

Gravity bleed usually does the trick for a clutch. Open the bleeder and walk away for a few minutes. Just make sure the master reservoir doesn't run dry, or you'll have to start over.

[banzai510(hainz)]

I just fill the resivor put tube in plastic bottle  it it drip abit. Do 2 or 3 pumps and fill res again and usually its good.

The bottle should have fluid in there already and if it suck it back up it will be ok as long as all the bubbles are gone.

 

make sure the slave is pushed in all the way. There is usually a spring to help it back but not needed as musch on a non adjust slave.

 

 

Nabco or Tokico is made in japan if found.  Slave Cylinders

Edited November 21, 2018 by banzai510(hainz)

[DIY 1985]

I just learned about reverse bleeding.  Pushing air down doesn't seem as good of a strategy as pushing it up.

https://www.brakebleeder.com/home/best-brake-bleeders-in-the-world/

[datzenmike]

Well you could throw money at it but the old way is faster and works. This might work better on complex anti lock brakes but the Datsun hydraulic clutch is about as simple and easy as it gets. Fluid is heavier than air and siphons down hill.  All that's needed is a 10 mm wrench for the bleeder and you can do it on the side of the road. 

[Stoffregen Motorsports]

I try not to re-invent the wheel whenever possible.

[DIY 1985]

Sure, but I'm already doing it a bit unorthodox, the FSM describes clutch bleeding as a two-person operation.  Obviously the clutch is way more simple, but if you have ever been doing brakes with two people, and the brakes are just not firming up, it is a bit of a pinch.  You kinda want more tools to try, plus I'll be needing to replace wheel cylinders before I get my second rig running.

[Crashtd420]

One of the biggest overlooked steps is bench bleeding the brake and clutch masters..... 

I had 2 people a vacuum bleeder and still had problems..... 

Once I bench bled the master (which can be done in the vehicle) I was able to get good pedals.... 

 

[Stoffregen Motorsports]

Vacuum bleeders and pressure bleeders both have their uses. I have and use both when, but nothing beats the two person pump and bleed system when doing brakes. We are talking about a clutch system though, which is about as simple as a peanut butter sandwich. Gravity bleeding works just fine 99% of the time on a clutch hydraulic system.

 

As Crash mentioned, it is important to have fluid cycled throughout the master first, but once you get that established, no special processes are required.

[Spiff]

Don't even need two people nowadays with those check valve brake bleeder kits, admittedly, it is kinda hard to see when your offside brakes are free of air though ?

Edited December 6, 2018 by Spiff
typo

[DIY 1985]

Got the master and slave in.  I was about to totally strip the flare nut, then it occurred to me that I could piggyback a vise-grip on the 10mm flare nut wrench to keep it from expanding open when torqued.  Couldn't quite yet get a tubing bender to cleanly make a damper bypass/delete.  Any suggestions on tools?  Not enough sunlight during the day to do gravity.  Just pump it like brakes, and bleed from the damper and master.  I paid like $8 from Autozone for a bleeder kit that had the right 1/8"-ish tube, and $2 from Ace for 1/4" clear vinyl tube.  Had the reservoir above the nipple with a hoop on the hose to catch bubbles.  Didn't use the reverse bleeder.  I put some teflon on the slave bolts going into the bellhousing because I get the feeling that the front seal on the transmission is leaking and sweating gear oil all over the slave via its mounting points.  I should have got the shift fork dust boot because I knew that it was toast.

 

Edited December 19, 2018 by DIY 1985
forgot the tip

[datzenmike]

Oil dripping out between engine and transmission? Probably the oil pan or rear seal leaking, so for the short term just keep the engine oil topped up. A leaking rear seal is not likely to get on your clutch.  Its much easier for oil from a leaking seal on the transmission to migrate to the front and get on the clutch diaphragm fingers.

 

If you suspect the transmission is leaking then it's imperative to check the oil level. There's no dip stick like the engine and if it gets low or dry, good-bye transmission. Figure out which one is leaking. There will be a fill bung (with square hole) about half way up the driver's side that takes a 1/2  ratchet or breaker bar. If you reach inside with your little finger you should be able to dip it into the oil. If low fill it with GL-4 80w90, NOT GL-5. Keep track of how much you add.  It holds two liters or 2 US qts. If just a cup, check it much later. If more it might be leaking so check more often. If you find you are always topping it up then it probably is leaking.

 

Petroleum (oil, gas or greases) will soften and dissolve rubber so keep it off the slave and clutch arm boots. Brake fluid is not petroleum based.

[DIY 1985]

I might have been a bit low on transmission fluid.  However, unless I had some already in the catch-basin, then I measured 2 liters collected.  The gear oil was changed early last year GL4 80w90, and was still kinda amber after 2,500 miles, not much synchronizer in the pan either, but the shifting seems to have become a bit easier after it was driven for a couple miles or so.

[datzenmike]

Two liters is recommended for filling the 71B by Nissan. So it would seem the oil pan or the rear seal is leaking.