SPROCKETS: DoT 5 Brake Fluid Rocks!

Doing some maintenance on my bike, a 1986 Harley-Davidson FLHT. Today's equivalent would be a "Something"-Glide They have so many names for them today, I can't keep up with them. Anyway, I've owned this bike since new. I opened the box at the dealer, actually, 8/13/1986, about 6PM.

I added a trailer hitch, trailer light connections, replaced the fender tip light bulbs with superbrightleds.com bulbs, and took a look at my rear brake system. It's been acting up a little lately and I want it back in top condition. The first couple of pumps after it has sat a while (like weeks or months) would be real soft to nothing there, then after it pumped up, it would be fine. I figured there was a small leak somewhere. So, I bought a MC and caliper rebuild kit from a internet friendly dealer. Now, I haven't been real good about changing the brake fluid on the bike. Actually, total maintenance on the rear brake system has been new pads put on at a dealer in about 1995 when I had a tire put on and they pointed out my pads were shot. I assume that they may have cracked the fluid resivoir at that point, but I'm not sure. You don't have to to change the pads. I think I might have checked the fluid level once about 1988. It is entirely possible that the fluid is original 1986 DOT 5, not 5.x as is sold today. I have about 77K miles on the bike.

I was expecting a full mess when I pulled it all apart. The resivoir is over on the left side of the bike under a cover and hard to get to, thus "out of sight, out of mind." There was a little bit of cloudyness in the resivoir fluid. Like a couple of whispy clouds just hanging there, not the whole thing cloudy. The color was still kinda golden. The master cylinder exterior had about 1/4" of aluminum worn away from one of my stainless braided oil lines (gotta tie that off and/or wrap it better), and inside, the seals looked a little bit worn but the bore was absolutely perfect. Amazing. This is the low point of the system, and I expected it to be like every other 20+ year old brake/clutch system I've had to pull apart: Rusted and/or corroded to junk. I put the new kit pieces in it with the supplied lube and went on to the caliper. The pin bolts were a bit hard to get out, so I put the whole assembly in the vice, added a little PB Blaster and carefully got them out without damaging them. On the bike I probably would have stripped out the allen heads. I popped out the piston and the bore had a couple places that were slightly polished from rubbing, there was a few tiny pieces of rubber floating in there and that was it. Looked really clean. I got that back together with the new pieces (two seals, a retaining wire ring and a piston: $40) and called it a night.

Anyway, I'm really impressed with DOT 5 fluid. The drawback is that (they say) at high altitudes, it gets mushy on you. I have noticed this effect when we go over 10-13K feet passes in Colorado. It isn't really bad, but it is noticeable. I think that's why the 5.x fluids came out. I don't know if they have the same chacteristics as the old DOT 5 fluid I had in there. I looked on my shelf and I have a whole (small) bottle of DOT 5 fluid that I bought 20 years ago and never opened. I think I'll go with that. The whole system probably takes 4 ounces. I also have about a half gallon of mil-spec brake fluid that my friend said was DOT 5, as used on M1 Abrams. I'm tempted to use that, but I think I'll stick with the store bought.

Dr. Hess said: "Something"-Glide

The term you're looking for is "Geezer" Glide.

In '04 or '05, they went back to DOT4.

My god man, I nag and nag to get you a forum to post in and you still post here?

That alzheimers is kicking your GeezerGliding ass!

There's a Sprockets forum? Who knew?

Tank fluid? Neat-o.

The DOT 5.1 is not a silicone fluid. It's a glycol based fluid, just like 3 or 4.

It would have been a LOT better if DOT would have designated it 6, not 5.1.

So, 5.1 doesn't mix then with 5.nothing? I'd use that tank fluid, but where to get more when I run out? I used to have the Mil Spec number of it, but I seem to have lost it and without looking it up, I'm a bit leary of trying to mix it with 5.

Anyway, I am very impressed with the DOT 5 stuff.

I got everything assembled back on the bike last night and the rear wheel put back on. My new hitch made getting the wheel in a bit more adventuresome, but it still went on. I didn't bleed the system or adjust the belt. Got tired and quit when I got the axle stabbed. I use a manual lift thing for most of my work, made from welded pipe. I have a hydraulic HF bike lift, but it is more stable to use the manual one. The hydraulic one will lift higher and get both wheels off the ground at the same time, or raise just enough to level the bike, which is handy for adding primary or transmission oil. When my 800 lb bike is up balanced on the HF jack, it is OK for some things, but not real stable for serious wrenching.

Race shops and good motorcycle shops should both stock DOT 5 fluid.

I know folk claim you can't mix silicone fluid with non-silicone fluid, but I rather doubt the brake system will fail as a result. At the worse, they should simply seperate and have one sitting below the other.

You can still find silicone DOT 5.0 fluid. I don't go shopping for it, but I do see it around. Worse comes to worse, e-bay. I bought a gallon there for something like $30, shipped.

foxtrapper wrote: The DOT 5.1 is not a silicone fluid. It's a glycol based fluid, just like 3 or 4. It would have been a LOT better if DOT would have designated it 6, not 5.1.

I think they share the same temperature ranges - but yeah. The silicone stuff should have a completely different rating so nobody decides to throw some 5 in with their 4.

$30/gal, sounds like I could go for that. Got a link to a seller or a pet search? When I get back on the Locost (after my bike maintenance is done), it is almost time to start filling the hydraulics. I'm kinda leaning towards DOT 5. It's all dry now, or dry with some residual 3/4 in it as a film and I can blow the system out.

I think this might be the guy I bought from. Looks like the same cans. If the link doesn't work, search ebay on "silicone brake fluid" and it's the dow corning cans, brown, one gallon.

http://cgi.ebay.com/ebaymotors/NEW-1-GALLON-Dow-Corning-Silicone-Brake-Fluid-DOT-5_W0QQcmdZViewItemQQ_trkparmsZ66Q3a4Q7c65Q3a1Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c293Q3a1Q7c294Q3a200QQ_trksidZp3286Q2ec0Q2em14QQhashZitem2c4f47f190QQitemZ190308675984QQptZOtherQ5fVehicleQ5fParts

Thanks. I put a bid on that one. He has a thousand gallons, so no shortage for a while. That's gotta be the same stuff I've been carrying around for decades from the tank. I think I'll go with that on all new brake/clutch systems now that I can't get the 3/4 synthetic Valvoline anymore.

Oh, and I'm real proud of that 'coon skin. It turned out real nice. It doesn't smell like 'coon any more either. I still need to work it to get it soft, but the fur is great and it looks fantastic. Can you use Lexol or Neat's Foot oil or something to soften it, or just work it on a sharp edge? Still not sure what to do with it. If I had about 10 more, I could upholster something, but given the amount of work that one was, I don't see that happening. And I'm all out of 'coon, so I'd have to wait another couple years for them to move back in. We just watched Mongol. Maybe a hat like Genghis Khan's.

I know you're a die hard GRMer, but HD dealers carry DOT 5 as it was specced for XLs until 2006 or so.

That's OK for the couple of ounces a bike takes, but what about the quart it takes to flush and bleed a car's system? Plus probably another quart to flush out the old stuff. At the two or three bucks an ounce a stealer wants, that could get expensive.

Cool, I'm glad that coonskin worked, cause that's a tough one to start with.

To soften the hide you use both, some sort of oil, and work it over a sharpish edge. Lots of folk use a shovel held in a vice as an edge to work the hide over. Go with caution, because it's real easy to rip a hide while working it over an edge, especially if you use a genuinely sharp edge.

I think I told you this once, but it bears rementioning, especially for others reading this thread who are fascinated by soft hides. Down in Tennessee I was admiring a gents hides because they were so soft. Right down to soft ears and even a soft nose. He told me his high-tech secret was an old clothes drier and square chunks of wood. He'd put the damp pelts and chunks of wood into the drier and just let it spin for days. No heat, and I don't remember if he said he had air flow going or not. Obviously the timer was bypassed. But having the hides being flexed and lightly pounded on by the wood chunks got them super soft. Never have tried it myself, but someday, I should.

Didn't get that email. I bet a HF cement mixer for a bill or so and a few cut up 2x4's would do just as well, and you don't have to hack anything, just turn it on. I try not to keep dead appliances around. I haven't gone completely native.

No, you just haven't built a front porch yet.

I have porches, I just keep the dead appliances off them. And the dead 'coons. And the occasional dead 'possum. And the dead mice, squirrels, moles and birds that the cat brings home. She's a killer.

Well, I got my rear brake bled last night. What a PITA. That was the worst brake bleeding I've ever run across. There was a very, very small leak where the banjo fitting bolted to the caliper. I had re-used the crush washers and this time, that didn't work. So, I could pump up the brake and it would hold fine, but when I let off the pedal, it sucked air in at the leak and I never could get the air out. I finally found just a slight amount of (silicone DoT 5) fluid at the fitting and bought some new Brake Best copper crush washers at O'Reilley's. After 2 days (evenings) of dinking with it, I put those on and 5 minutes later, it was bled.

foxtrapper wrote: I think I told you this once, but it bears rementioning, especially for others reading this thread who are fascinated by soft hides. Down in Tennessee I was admiring a gents hides because they were so soft.

Is this one of those "biker" things? Like a jeep thing but with a guys hide? Sounds fishy...

foxtrapper wrote: I know folk claim you can't mix silicone fluid with non-silicone fluid, but I rather doubt the brake system will fail as a result. At the worse, they should simply seperate and have one sitting below the other. You can still find silicone DOT 5.0 fluid. I don't go shopping for it, but I do see it around. Worse comes to worse, e-bay. I bought a gallon there for something like $30, shipped.

Well, this might not be an apples to apples comparison, but, I have seen DOT 5 mixed with DOT 3 more than once, and the results were ugly and included brake failure due to ruined seals. This happens not on cars or bikes, but on forklifts; crown forklifts use only DOT 5, (for reasons that I am not quite sure of, possibly use in freezers?), any way generally speaking, only crown techs know this, and despite the fact that there is a label on the reservoir that says silicone brake fluid only, every non crown tech unfailingly refills them with DOT 3. I have replaced many a master cyl, wheel cyl, slave cyl and swivel fitting due to mixed brake fluids.