Clutch/Brake fluid

[bazwell]

With speed bleeders you wouldn't even need the wife

You could just trade her in! :rofl_200:

 

[naughtyG]

It was the clutch line that I bled....seemed to work fine. I don't know why you would need to reverse bleed if no air entered the system. I have clean fluid in my system now and the bike shifts fine. I would understand the reverse bleeding if you emptied the system..new lines..rebuilt MC..but if you're just pushing fluid through it and don't let it run dry it works...at least it did for me.

yes it makes sense if no air entered the system. However your slave cylinder will still have the old fluid in it. Just leave it though it won't make much of a difference :clapping:

 

[Fire-medic]

He said the fluid he was getting thru the bleeder hose was fresh. There should be very little original dirty oil in the entire system, including the slave cyl once the fluid starts running 'clear.' I don't believe there is any reason you can't use the Mityvac or a traditional purge the way he did it to the clutch. Sure, you can reverse-flush if you want to. The main advantage there is that theoretically, if you have points in the system where bubbles may 'sit' then the reverse-flush should help them to 'migrate' to the highest point, the master cyl. In principle, the clutch and brake both work the same, pushing fluid from A (master cyl) to B (brake caliper(s) or C (clutch slave cyl). The only real difference is in the perceived 'feel' at the lever as the movement required by the fluid for brakes is only-enough to have the pad(s) contact the disc(s), which hopefully is about 1/2 of the lever'r travel to the handlebar. For the clutch, the travel to the bar is enough to make the slave cyl push the clutch pushrod against the diaphragm clutch in the (stock) clutch friction/steel disc pack so as to unload the friction discs from contact w/the metal discs, and thereby 'uncoupling' the engine from the transmission just after the primary drive. You aren't coming-up against a rotor, you're creating enough space in the clutch pack so the friction discs and clutch plates can be bathed in oil and 'break' their grip on ea. other.

Incidentally, I just checked the torque value for the slave cyl machine screws, it's 8.7 ft/lb. for the bolts to secure the slave cyl housing to the engine case. Sounds like someone must have way-overtorqued the bolts on TX SS's slave cyl. if one wrung-off while he was trying to remove it.

 

[naughtyG]

When I changed my clutch line to a new SS one, I tried conventional bleeding and got nowhere - could not build pressure in the line at all. As I have no mightyvac I was stumped and couldn't ride. Then someone suggested the reverse bleeding with a syringe (which I did have) and it worked a treat!
I'd never come across this problem before in bleeding car and bike brakes, but on the Max clutch there was just no way conventional bleeding would work once air was in the line.
Glad he didn't run into the same problem!

 

[tonyg-5386]

Well, if I ever decide to replace the clutch line or rebuild the MC I will certainly make sure I have a mityvac and/or a syringe to make sure I don't have a hard time. I would always rather be prepared for a "worst case scenario" than be stuck with a 600lb paper weight in my garage.

 

[Fire-medic]

Did you fill the slave cyl 1st before installing it? Whether calipers or a slave cyl, filling the receptacle 1st will greatly-reduce your bleed time. From the piston dia & travel, you are displacing only ~3 ml. of fluid w/ea. full compression of the lever. If you have a totally-empty system w/fluid only in the master, it is going to take you a long time to fill the system. I have used my mityvac on bikes, cars & trucks over close to 30 years and have never 'not been able' to bleed a system, including slaves of four-wheel vehicles' clutches. But 'whatever works,' that's what is best for you.

 

[gamorg02]

thats the exact stuff i use. seems to work great. its readily available too which is nice. also that way u don't have to decide between 3 and 4

 

[Fire-medic]

I had a bad clutch master cyl on my FZR1000 so I tried rebuilding it & it still leaked, & the plunger hung-up, not returning, so it's a bad cyl or a bad kit, I dunno. I bought a new master cyl, bled it w/my Mityvac, and took it for a ride, but after about 5 mi. the friction disengagement point came closer to the handlebar, so, back-home. I removed the slave & saw it was weeping at the bottom, or at-least the cyl piston was wet there. So, I disassembled it, used my Demel moto-tool to grind the crud out of it, cleaned-up the piston on the wire-wheel/bench grinder, used brake cleaner to get everything clean and reassembled it keeping my fingers crossed.

I also decided to try 'NaughtyG's' backflush method. I got a 50 ml syringe w/a tapered hub, just-right for slipping-on a length of clear plastic tubing.

First, I used a hose clamp to tighten a 6" piece of clear-plastic tubing to the slave bleeder nipple after I slipped-on an 8 mm box end wrench. Having already filled the slave cyl w/new brake fluid DOT 4, I filled the syringe, removed the master cyl reservoir cap, and began purging the syringe of its DOT 4, carefully pushing on the plunger. It's probably a good idea to leave the master cyl cap in-place while backflushing the system, as the small weep hole in the master cyl floor will shoot a jet of fluid more-than a couple of inches into the air... just remove it & see what the level of fluid is like, use the syringe to remove some if it's getting close to the top. It helps if the bike is on its center stand or a swingarm stand if you gotta kerker 4/1.

So after seeing nothing but DOT 4 coming into the master cyl, I shut the slave cyl bleeder. Then I pumped repeatedly the clutch lever, and the pressure-point began moving further from the bar. The first few squeezes were 'no-resistance,' but then it started to show an engagement point where it was moving the clutch diaphragm. After it got where I would consider it 'normal,' I backflushed it w/the syringe one more time, not too-much, just enough to demonstrate no tiny fizzy-bubbles came-out of either master cyl holes, and with the slave bleeder closed, a gentle clutch lever squeeze about 1/3 of the way to the handlebar resulted in a nice little geyser of DOT 4 erupting from the small master cyl piston hole. Throw the reservoir top on, clean-up any spills and you are ready to go!

And that's where I am going, out for a nocturnal test-run to try-out 'naughtyG's' method for its results, thanks for the suggestion. No Mityvac was used in this bleeding event.

 

[naughtyG]

No Mityvac was used in this bleeding event.

Haha. I didn't have one so no choice! To be fair I think it was Spursmech's suggestion, that whole reverse-bleeding plava.

Got me out of trouble though! :clapping:

 

[sdt354]

I used it no prob. I try to change all the fluids once a season, anal for sure but that's how I am. I replace it the way you did. I just bleed till fresh fluid comes out. My masters and clutch slave are all new since I bought the bike 6 years ago, they were a victom of low milage, but little use. I try to use a new can of fluid though. Not stuff from my cellar a couple of years old. Mineral oils are very hydroscopic (absorb moisture from the air). I'm not sure about the new synthetics though. I tend to think synthetics are not so hydroscopic from my refrigeration work days.
It doesn't take long for the brake fluid to get crappy looking.
Steve-o

 

[Fire-medic]

So after working on the slave cyl on the clutch of my FZR1000, I went out for a ride, and again after not very far I got the clutch friction point come creeping back towards the bar. Back home! Removing the slave cyl and checking the master cyl & the line, I could find no leaks!

I assumed that maybe the interior of the clutch hose was porous, although there was no exterior indicator of it. Because the rubber line runs thru the aluminum beam frame member, I tied a ductile steel wire, the kind steelworkers use for tying rebar, to the end of the hose before I pulled it out, you could use some solid copper wire in maybe 12 ga. alternately. That is to make it easy to replace the new hose. So off the my friend Steve, at Under Pressure, in Dania Beach FL, the bike shop where my engine is undergoing rebuilding after its Bad Day at the Dyno. The dyno run that lunched my engine was not at his shop.

Anyway, he fabbed a new clutch line from bulk s.s. flex tubing. It was $65 o.t.d while-I-waited, and because I like to get that kinda service, a 'fin' for the beer kitty.

Back-home, when I got a chance to replace the line (today) I at-first thought I had it bled sufficiently, and was getting ready to take a test ride. But-the friction point for the clutch lever started to come-back towards the bar w/successive squeezes, and I could have sworn I had it fully-bled! I had used the backflush-syringe method instead of my Mityvac. Again I checked everywhere for leaks-none. I removed the slave cyl. & turned it upside-down, still hooked to the line, to help any possible trapped air 'migrate' into the hose so it could 'work-upwards' to the master cyl. Hook-up the syringe for another reverse-bleed, do that, and I left the slave bleeder nipple open while I squeezed the clutch lever. I was rewarded w/a good amount of fluid moving into the syringe, and since I had light pressure on the syringe plunger, I could feel the fluid promptly moving as the master cyl piston moved from the lever movement. No air bubbles into the syringe, so I put a bit of pressure on the syringe piston as I closed the slave bleeder.

The next squeeze of the lever was immediate 'far-from-the-bar' resistance, and it felt like it should for lever resistance against the clutch springs (individual as-opposed to the VMax diaphragm). Now I squeezed the &*^&%@## out of it repeatedly and so-far, it hasn't changed. I am in the middle of a ride to check on the function, and this time, it appears as though the clutch repair may finally have taken-hold. So, it was multiple things that needed to be done for maintenance and repair. And, the reverse-flush did OK. :biglaugh:

The place I stopped-in to check on things is my other friend Steve's shop, which is a big seller of bike tires, batteries, chain/sprockets, helmets, clothing, etc., Competition Cycle Center also in Dania Beach FL. compcyclecenter.com

And, while talking with my friend Enrique, who works there, I saw some Hap Jones std bore piston rings for a Yamaha RT-2 on the table where the computer terminal on which I am writing this is located. So, I scooped them-up and am soon to leave with my aftermarket n.o.s. piston rings for my dirtbike I bought new in 1972 and still have, and some delicious smoked fish dip Steve has delivered from a local small businessman. And my clutch adjustment hasn't changed! Sounds like a good day for these reasons.

Enrique also showed me a bike he bought for export, it was in Pensacola, a 1983 Venture Royale he bought wholesale for export to So. America. It's in perfect condition, fully-loaded and w/many accessories. With shipping to FL it cost <$1700. He sends an ISO container every ~8 weeks to So. America filled w/bikes, cars, trucks, whatever his contacts there want. He also just bought from MI an Arlen Ness Victory Vision, a 2009, it's #32 in the production run. It was dropped on the right side but $1K should buy the parts to fix it, he paid $7K.

Enrique does the internet sales for Competition Cycle on ebay Motors, under competitioncycle123. They post thousands of n.o.s. o.e.m. parts annually. Right now I have sitting in-front of me a box of rebuild kits for Red Wing shocks, the top eye & piston & shaft ***'y. complete. There are all-kinds of things like that in stock, they are continually acquiring failed businesses' inventories and posting this stuff.

OK, time to ride! :biglaugh:

 

[Samy]

DOT 3 for hydraulic clutch and for front brake too?

 

[Fire-medic]

DOT 3 for hydraulic clutch and for front brake too?

Same answer I gave in the other thread: DOT 3, DOT 4, DOT 5.1 but NOT DOT 5. Both front & rear master cylinders, both brakes.

 

[Samy]

Thanks a lot

 

[65Corvair]

After rebuilding, I used DOT5. I've used it in my antique car as well. It doesn't absorb water so it doesn't allow any rust or corrosion. It cannot be mixed with any other DOT fluids, it must be DOT 5.