Author Topic: Brake Fluid (Read 16220 times)

Loudpipe · « **on:** September 19, 2006, 01:50:11 PM »

What type of brake fluid should I be using in a CB750? DOT 3, right? Is mineral based brake fluid compatible with this, or will it eat the seals in the master/slave cylinders and caliper?

nickjtc · « **Reply #1 on:** September 19, 2006, 01:52:58 PM »

Isn't DOT 3 mineral based? As long as you use the type (DOT 3/4) that the OEM recommends you shouldn't have any problems.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #2 on:** September 19, 2006, 04:32:48 PM »

DOT3 is whats called for. I think DOT4 is basically DOT3 with a higher boiling point therefore it should be fine or even better. This will probably start a debate again. I am currently running DOT5 silicone in my freshly rebuilt front caliper since I had the caliper & rotor center and both fork lowers powder coated. Working fine. My rear (75 750F) has DOT3 in it and is also working fine. DOT5 won't eat paint. DOT5 can/might absorb moisture from the air more than DOT3. DOT5 apparently doesn't change color like DOT3 does when it absorbs moisture. Sticky calipers suck. Caliper rebuilds suck. Honda doesn't have new caliper pistons any longer. After market pistons are available but not cheap. Pistons corrode due to moisture. ETC, ETC, ETC. So with all this in mind, either seems to work fine.

Moral of the story, install Speed Bleeders and flush your brake systems every year no matter what type fluid you use. Only takes a few minutes with Speed Bleeders. Pain in the ass without! Worth the small investment. I started doing this after 30 years. Perhaps you can teach old dogs new tricks

Jerry

jaknight · « **Reply #3 on:** September 19, 2006, 04:58:54 PM »

A Strong Second vote for SpeedBleeders!!

One week ago I installed a SpeedBleeder. Man, what the he** took me so long?!!!

They are great. The time and headaches they save are easily worth their price right off the bat!! In no time they are going to pay for themselves in saved aggravation.

My Disclaimer ---------> I do not work for or have any connections to Speed Bleeder......... except that I bought their product and am very happy with it........

P.S. Don't necessarily go by Speed Bleeders size charts. My '74 cb750 K4 took a 10mm size; their charts said 7 or 8mm ..............

~ ~ ~ jaknight ~ ~ ~

Loudpipe · « **Reply #4 on:** September 19, 2006, 06:05:12 PM »

I keep thinking that the Castrol brake fluid I have might not be compatible with all systems though. I know that some people try to add a certain type of brake fluid to their Triumphs (cars) and it ends up eating up the seals, because they are not compatible, but I can't remember which ones it was.

I can always go out an get some DOT 3, I was just wondering if the Castrol mineral based brake fluid (which is NOT labeled as a DOT fluid, but exceeds DOT3 regulations) would work or not.

Loudpipe · « **Reply #5 on:** September 19, 2006, 06:09:51 PM »

I found the SpeedBleeder website and I'm sold. Can't really beat $7.00 to save you a ton of trouble. What size would my '78 750F take? I would assume that the lines are the same size as your K4, but I don't know for sure. Also, are all the lines the same size (front & rear brake)? I assume that's all the hyrdrolic lines you would need a SpeedBleeder for. These Hondas have cable clutches, right?

gar · « **Reply #6 on:** September 19, 2006, 07:17:08 PM »

Ok, I'm sold... will buy a Speed bleeder and add this to my growing list of winter MC maintenance activities. I have a question: who says the fluid has to be changed every year?

Regarding DOT3 v. DOT5...I googled it, read a few articles, and have concluded I will just keep using the recommended DOT3. It is so cheap, and why invite some heretorfore unknown problem that silicone based DOT5 might cause?

OldSchool_IsCool · « **Reply #7 on:** September 19, 2006, 07:19:15 PM »

I read up on SpeedBleaders too and am prolly going to get some. Is their web site the only outlet?

jaknight · « **Reply #8 on:** September 19, 2006, 08:09:57 PM »

Hi OldSchool,

I have been told that some auto shops, and especially performance/speed shops, carry the Speed Bleeders.......

~ ~ ~ jaknight ~ ~ ~

nickjtc · « **Reply #9 on:** September 19, 2006, 08:14:02 PM »

Quote from: Loudpipe on September 19, 2006, 06:05:12 PM

I keep thinking that the Castrol brake fluid I have might not be compatible with all systems though. I know that some people try to add a certain type of brake fluid to their Triumphs (cars) and it ends up eating up the seals, because they are not compatible, but I can't remember which ones it was.

I can always go out an get some DOT 3, I was just wondering if the Castrol mineral based brake fluid (which is NOT labeled as a DOT fluid, but exceeds DOT3 regulations) would work or not.

Doesn't look like anyone can answer your question! I would go out and get some DOT 3 just to be on the safe side.

Rsnip988 · « **Reply #10 on:** September 19, 2006, 09:48:15 PM »

Good call

Jerry Rxman Griffin aka MuthaF'er · « **Reply #11 on:** September 20, 2006, 12:38:54 AM »

Quote from: Loudpipe on September 19, 2006, 06:09:51 PM

I found the SpeedBleeder website and I'm sold. Can't really beat $7.00 to save you a ton of trouble. What size would my '78 750F take? I would assume that the lines are the same size as your K4, but I don't know for sure. Also, are all the lines the same size (front & rear brake)? I assume that's all the hyrdrolic lines you would need a SpeedBleeder for. These Hondas have cable clutches, right?

Not sure about the 78 750F. It has different brakes than my 75 750F but I can tell you mine uses 2 different sizes. Don't go by the wrench size you use as some may have you do. Both of my bleeders use a 8mm wrench but the back is a 8125 (8mm threads with 125 thread pitch) and the front is 7100 I believe (7mm threads with 100 thread pitch). I corrected this post 9/22/06. I had the front and rear part numbers reversed

eldar · « **Reply #12 on:** September 20, 2006, 06:28:33 AM »

I gotta get some speed bleeders too. As for fluid, I use synthetic. It does not absorb moisture like dot3 does. I know some people like to spout horror stories about using anything other than dot3 but me and several others here use synthetic based fluids with NO trouble.

Either way, flushing your system at least every couple of years is a good thing. You will clean out the crud that somehow finds its way in and you will remove any water in the system. Both of these things cut down on braking power. I dont care what fluid you use. Both work fine.

dusterdude · « **Reply #13 on:** September 20, 2006, 10:25:02 AM »

just for ya`lls edification,i put dot 5 in my bike a little over a year ago and everything is working just fine.

Dave Wyatt · « **Reply #14 on:** September 20, 2006, 10:27:52 AM »

I use silicone brake fluid in the Honda without any problems. I have also used it in my 1970 4-4-2 since 1984, when I rebuilt the brake system. 30,000 miles in 22 years without a problem. I have had to top it off a couple of times. The car sits more than it gets driven and the brakes are always ready. Horror stories are just that, stories. Try it and make up your own mind.

cmorgan47 · « **Reply #15 on:** September 20, 2006, 10:56:20 AM »

Quote from: OldSchool_IsCool on September 19, 2006, 07:19:15 PM

I read up on SpeedBleaders too and am prolly going to get some. Is their web site the only outlet?

just order it from them. under $20, the guy is quick and replies to email immediately.....
although, he includes a link to his new 400/4 site that has way too much tempting pricey stuff.

[edit]
if you go to the new site included above, he said the shopping cart isn't working yet so you have to email him with request

dusterdude · « **Reply #16 on:** September 20, 2006, 01:28:56 PM »

oh,forgot to say ive had dot 5 in the panhead longer than eldar had hair.

eldar · « **Reply #17 on:** September 20, 2006, 02:59:59 PM »

Dont you mean longer than you HAD hair!

techy5025 · « **Reply #18 on:** September 20, 2006, 08:45:07 PM »

...and Dot 5 does NOT absorb water.

Jim

Loudpipe · « **Reply #19 on:** September 21, 2006, 08:17:24 AM »

Is it possible to completely bleed the DOT 3 fluid out of the system and then fill them back up with DOT5, and have the effects off DOT5 without having to rebuild everything with new seals and all?

Jerry Rxman Griffin aka MuthaF'er · « **Reply #20 on:** September 21, 2006, 08:50:48 AM »

Quote from: Loudpipe on September 21, 2006, 08:17:24 AM

Is it possible to completely bleed the DOT 3 fluid out of the system and then fill them back up with DOT5, and have the effects off DOT5 without having to rebuild everything with new seals and all?

I think so. I did not rebuild my master cylinder but I rebuilt my caliper due to a leak (cleaned, new seal, Speed Bleeder, lubed with silicone grease) I went with DOT5. I filled and bled the system with DOT5, opened the bleeder and flushed all DOT5 out then refilled and bled again with a fresh fill of DOT5. Guess I couldn't say for sure since the caliper has a new seal rather than an old one. Works fine.

dusterdude · « **Reply #21 on:** September 21, 2006, 08:54:24 AM »

yes,but you must clean the system real well.

Loudpipe · « **Reply #22 on:** September 21, 2006, 02:26:39 PM »

Clean the system as in flush new DOT5 through it a few times?

nickjtc · « **Reply #23 on:** September 21, 2006, 02:30:36 PM »

Don't quote me, but I seem to remember reading that anything non-metallic that has come into contact with non-DOT 5 fluid has to be replaced before you can use DOT5.............

Loudpipe · « **Reply #24 on:** September 21, 2006, 02:39:11 PM »

See, that's what I thought too, but I'm not sure.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #25 on:** September 21, 2006, 05:21:28 PM »

My master cylinder still works fine and I flushed 1 filling of DOT5 through it before refilling and capping it off this spring. So far so good. The front brake is THE most important part of my bike and I keep a very close eye on how it functions. This comes from a guy that has survived a head on crash with a 1985 Ford Econoline van pulling a pop up camper.

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Author Topic: Brake Fluid (Read 16220 times)

eldar

eldar