Basic Maintenance: Brake Fluid

[rdprdp01]

Very comprehensive rdprdp01. I would add the brake fluid testers are extremely cheap now and it is a simple task to test the amount of water content in the brake fluid resovoir. Up to 4% is considered the limit but you might make a choice to replace earlier. It is hard for the brake fluid to ingest water as the resovoir does has a flexible rubber cap, the pinhole is above that to allow for expansion and contraction of that cap without fully exposing the resovoir fluid to any more air than it currently is. Not impossible of course, I have a classic car sitting here with 5% plus contamination and it is only 3 years since its fluid replacement.

While you were there you might of done the clutch fluid, it's an easy change too.

Thanks for the suggestion. To be candid, I was not even aware that a brake fluid tester existed! I have noticed that there are are several price points for various testers. Please advise if you think this unit would make a reasonable addition to my tool collection:

QRPKIng AS501

As for the clutch fluid, sadly work is getting in the way of my quality time with my CB1100EX. The clutch fluid change is on the list of things to do after I take care of a few more maintenance items. Thanks again for the suggestion. I really enjoy your Threads and Posts. David

[Tev62]

Very comprehensive rdprdp01. I would add the brake fluid testers are extremely cheap now and it is a simple task to test the amount of water content in the brake fluid resovoir. Up to 4% is considered the limit but you might make a choice to replace earlier. It is hard for the brake fluid to ingest water as the resovoir does has a flexible rubber cap, the pinhole is above that to allow for expansion and contraction of that cap without fully exposing the resovoir fluid to any more air than it currently is. Not impossible of course, I have a classic car sitting here with 5% plus contamination and it is only 3 years since its fluid replacement.

While you were there you might of done the clutch fluid, it's an easy change too.

Thanks for the suggestion. To be candid, I was not even aware that a brake fluid tester existed! I have noticed that there are are several price points for various testers. Please advise if you think this unit would make a reasonable addition to my tool collection:

QRPKIng AS501

As for the clutch fluid, sadly work is getting in the way of my quality time with my CB1100EX. The clutch fluid change is on the list of things to do after I take care of a few more maintenance items. Thanks again for the suggestion. I really enjoy your Threads and Posts. David

Yes, that looks OK. There are so many on the market. I got two from Ali-Express, less than $5 each I think. I got two just to check they read the same. And as you are stuck for time it would take you 2-3 minutes to check the fluid in the resovoir.

[rdprdp01]

True that, Tev62. I knew it would take some time to touch up the photos and create the "How To," so I did both after I changed the brake fluid. Sadly, the clutch fluid is still aging like fine wine.

My time management and work/life balance needs some work, too. David

[rdprdp01]

My biggest reservations are the length of this procedure and the fact that brake fluid is pumped in the opposite direction of normal flow, meaning that any sludge that has accumulated in the calipers must be flown through the ABS, brake master, compensation port, and back to the reservoir, as well as air bubbles in the brake system when this procedure is completed.

I ultimately came to the same conclusion, which is why I followed the traditional method. And I feel particularly proud of my decision after reading your post. You remain my mechanic role model! David

[Lunchbag]

This may be a dumb question.  I'm trying to replace the rear brake fluid but no fluid is moving through the tube connected to the loosened nipple as I depress the rear brake pedal repeatedly.  There is plenty of fluid in the reservoir.

I had no problem with the front brake fluid.  It flushed through just fine by pumping the brake lever.  Maybe the rear doesn't work the same way?

[Lord Popgun]

On my ‘13 non-abs model, that is how mine works. Loosen the nipple and pump the brake-fluid comes out. I think it is the same for ABS bikes. Have to look in the manual though.

[Cormanus]

That's how mine works too (2011 non-ABS).

[peterbaron]

..... I'm trying to replace the rear brake fluid but no fluid is moving through the tube connected to the loosened nipple as I depress the rear brake pedal repeatedly.  There is plenty of fluid in the reservoir.

....

but is the brake pedal hard, soft, sinking and going down when the nipple is loosened or..???
Was the robber cap missing from the bleeder??

[Gone in 60]

One thing the Royal Enfield 650 is famous for is frequently having to bleed the rear brake. There was a recall on rear calipers for people who live in wet environments with calipers that tend to corrode, but living in a dry area and never really getting my bike wet, I haven't thought about that much. But, when mine sat for four months, I found that the rear brake was totally shot the first time I rode it. Air had entered the system and the pedal sank all the way with no pad movement. Only took a few minutes to bleed it and a lot of air came out. Since it's been such a widespread problem, the pundits on the RE forums have been talking about it. One of the current thoughts is that overtightening of the bleed screw when snugging it down after a bleed procedure might be allowing air to enter. Very interesting thought, one I had never considered.

On the BMWs, I have a GS-911 tool that connects to the bike's diagnostic port and can mimic all of the regular dealer service functions. When bleeding brakes, one part of the job is an "ABS bleed-down", which cycles the ABS pump a few times to release any trapped air, then you bleed a second time to release anything that came out of the pump. I've never heard of this procedure being specified in either Honda or Enfield service manuals for brake bleeding. It might just be BMW's overly-German maintenance process.

As for flushing and bleeding the clutch fluid on the CB1100, I do it every time I flush and bleed the brakes (every two years). I've already got the fluid, rags, tools and floor cardboard out, so it's a good time to get it done. Plus, if I've already opened a bottle of brake fluid, I want to do everything I need to do with it, as I'll probably toss what little is left in the bottle.

[Lunchbag]

but is the brake pedal hard, soft, sinking and going down when the nipple is loosened or..???
Was the robber cap missing from the bleeder??

It was soft.  Since I was pressing with my hand I probably didn't notice how soft.

This morning with everything put back together I rode the bike slowly up and down the driveway.  I had already test-ridden after changing the front brake fluid and I knew it was good.  Wanted to check the clutch since I just changed that fluid also, and it worked fine.  The rear brake was soft and did not actuate the brake.  After very many presses it finally firmed up and worked normally.

So I went back to the garage and repeated the fluid replacement on the rear brake and it worked.  I'm not exactly sure why I had trouble with it before.

However I did notice one thing.  After a few pumps of the rear brake lever, the fluid stopped flowing through the tube.  I couldn't figure out why until I noticed that my 5/16 wrench that was on the bleeder valve had swung and closed the valve, due to gravity.  So I held it open with one hand while pumping with the other.  Then I switched to the open-and-close routine on the valve for each pump of the brake lever and this made the fluid move along better.

Another short test with everything together showed all good.  I'll do a longer ride later.  Thanks to all!