Time to upgrade my front brakes.

[Flyinfool]

I definitely need better front brakes.

I did the delink and had better braking power before the delink.

I have SS lines.

Very fresh Dot 4 fluid.

HH pads.

Stock calipers and Master.

 

I did rebuild the master as best I could but there was some very deep pitting at the bottom of the stroke that I could not hone completely out. I did not rebuild the calipers but they were working perfectly at the time if the delink.

 

It feels to me like there is still some air in the system, but I have bled every which way there is and and then some. I can easily pull the lever all the way to touch the grip and that only gives me moderate stopping power.

The bleeding tricks I have tried;

normal bleeding with the pump bleed tighten release.

vacuum bleeding buy pulling a vacuum at the bleeder.

pressure bleeding buy using pressure to force fluid backwards thru the system.

bleeding at each banjo bolt.

bleeding with the bike almost laying on its left side.

bleeding with the bike almost laying on the right side.

bleeding on the center stand

bleeding on the side stand

wheel turned right

wheel turned left

wheel straight

tying the lever back overnight.

Dot 3 fluid

dot 4 fluid.

AND many combinations of the above.

I have pumped 3 QUARTS of break fluid thru trying to find that last air bubble.

 

OR what did I miss.

 

I am at a point of starting over? I have tried 2 different masters and they were both just as pitted as my original one.

I am thinking of getting a NEW 16mm master and a set of R1 calipers. The new SS lines should be fine.

I will try the new 16mm master first.

 

I need to get this figured out before MD.

There is no way that these brakes are going to stop in a reasonable distance once I attach the trailer.

[Venturous Randy]

When I put SS lines on my 83, I used a speed bleeder to move the fluid much faster. Now, mine almost catches too far out and are solid as a brick. Did you bleed at the goose neck? 83's do not have that bleed point.

Randy

[Flyinfool]

I have an 88 so it did have that bleed point. But since I have delinked The high point is gone comepleely.

[BlueSky]

This may be totally irrelevant. But, on an auto, if you don't bench bleed the master cylinder before you install it, it will take forever and a day to get all the air out by bleeding at the calipers. I recently installed a new MC on my 2002 F150 and it took a looong time and a lot of stroking to get all of the air out with the MC clamped in a vise. The new MC came with tubes that hooked to the outlets and the other end was inserted into the reservoir so I wasn't using a ton of fluid. It was being recycled and since the tubes were clear, I could see when the air bubbles finally disappeared.

 

Also, I thought the idea was to go to a 14mm MC to give better control. From what i've read the stock MC has a 5/8" piston??? I don't know much about this idea.

[BlueSky]

From what I've read you will have to buy more SS brake lines to fit the R1 or R6 calipers. The hose has to be rotated 90 degrees to connect and the SS hoses can't be twisted. I don't know. But, I read it in one of the posts on this site.

[Flyinfool]

OK I had a thought last night. Yea I know, me having thoughts is usually a dangerous thing..................

 

While working on the steering bearings I may have had the Master cylinder sitting upside down while draped over the side of the bike. this could have let air into the pump chamber of the master. Tonight when I get home I will bleed the master to see if that may be the case.

 

Even if that is the case and it gets me back to where I was, that is still just ok brakes not great brakes.

The stock master on the MKIs is a 1/2 inch (12.7mm) bore, the stock master on a MKII is 14mm (9/16 inch) bore. That 14mm bore was designed to operate just the right caliper. So I am thinking that going to a 16mm (5/8 inch) bore like what is used on some bikes with dual front calipers might just work better.

[BlueSky]

I just went to the garage and looked at my 89's MC. There is a "14" stamped on the side. Your idea of going to a 16 sounds logical to me.

[Yammer Dan]

Then you will be doing Stopies all the time......

[syscrusher]

OK I had a thought last night. Yea I know, me having thoughts is usually a dangerous thing..................

 

That 14mm bore was designed to operate just the right caliper. So I am thinking that going to a 16mm (5/8 inch) bore like what is used on some bikes with dual front calipers might just work better.

 

The original 14mm does a fine job of expanding my dual front R1/R6 Blue Dot caliper pistons. Do you have one line down and a loop over the fender or two lines down? When I bled mine I had Speed Bleeders and two lines down. I bled left then right then left again and then right so that I was sure there was no cross over at all. It allowed the air to consolidate similar to tying the lever overnight maybe. I thought the speed bleeders really were useful. I had a lot more trouble getting the rear brake right after delinking and replacing lines though. It was more difficult to keep the mc filled and know when it needed fluid.

[Flyinfool]

My rear is wonderful, pads are good, I aint touching it.I can just barely get it to lock if I really make an effort at it.

 

My front has a single line down from the master, that goes to a V-Max splitter and then 2 lines down from there.

 

A 16mm master is a lot less money than the R1/R6 calipers. Even if I do go with the R1/R6 calipers I still need a new master, I think the badly pitted master is a big part of my issue.

 

It seems that I did get some air into the master while the bars were hanging upside down during the steering bearing job. I bled the system at the master banjo bolt after it sat for 24 hours so all of the air could float up to that point. I then bled the whole system normally. The front brake is at least now back to where it was, not great but rideable. I still want to get it better.

[Guest Jamsie]

the best thing i have ever used for bleeding lines i got from an auto parts store in uk ,

basicly its a short length of rubber hose with a non return valve, the end is plugged and slots in the hose between the plugged end and the non return valve.

if you go to larger dia piston master cylinder you will have very fierce brakes with no feeling , smaller piston will give a lot more feel .

when doin the r1/6 conversion you can get a master from the road star line , 2 versions , 5/8 and 14mm which fit 1" bars

[GaryZ]

I am not sure what is causing your issues. I can tell my story; I de-linked my '85 by connecting the stock front master to a Kawasaki splitter and two new braided lines to the front calibers. The hose from the master to the splitter is one of the original rubber hoses and it is too long. I disabled my anti-dives by removing the hoses and capping the ports. My front master has an adjustment for stroke and I adjusted to max (under the brake handle). No joy trying to bleed the beast until someone suggested the tying handle trick. Bleeding took two nights of pumping the system and tying the handle, then bleeding at the master's banjo bolt. My front brakes now work ok. However, my back brakes hardly work at all after gutting the proportioning valve! How did you get yours good enough to lock up the rear wheel?

[Flyinfool]

Gary

I have played the tie the handle back game a lot, to no avail.

I am also contemplating getting rid of the splitter and just get 2 new long lines made up with a double banjo at the master.

 

 

For the rear I gutted the proportioning valve and then plugged the hole where the rear line used to attach and my braided stainless line is connected to the port that used to go to the front left caliper. I do not know if the different port makes any difference once the valve is out other than it is easier to get to.

 

I also have HH pads in the rear and both fronts.

[GaryZ]

I used two lines on another project and I plan on changing my '85 sooner or later.

My rear brakes are connected to the original port on the master because it was already there.

I'm confused as to why you say it was easier to use the front port . . .

 

Part of the reason for my post was to mention that I successfully used the original front master, even though others claimed it would not work.

 

Here is a 17mm front master that I used on a Can Am Spyder project; $51

[Condor]

From your original post you did say you honed out the master, and it did have some pitting at the relaxed position.. ?? ... So what's happening is even tho you're pulling on the lever, the pressure isn't building up until the rubber cup moves a ways down the cylinder. Personally I'd replace the master/reserve with another. If the 14mm worked before, changing it to a bigger will actually help, but not for the reasons you'd think. It would replace the honed/pitted master you have now.... My 2¢