RK Front Master Cylinder
#1
RK Front Master Cylinder
I have now had my bike at the local Indy I use twice trying to get the front brake to be more responsive. The brake works fine, but has quite a bit of take up. They rebuilt the front master, and it is now a little better. When we were talking about it he said that it is an after market chrome kit, and it just may never be able to built the pressure that the stock cylinder will. This was all installed by the previous owners shop he used.
I guess I am just going to take the cheaper route for now and put a stock black one back on. Then I will just get the chrome cover for it. Just wondering if any of you all know where a good place to find a take off would be? If now I will just browse Ebay.
Also, do you all happen to know what fluid would be used in an 05 Road King Custom braking system? I have been told by a few people that they were still using DOT 5 that year. My rear master cover says DOT 4 so it leaves me a little confused. I know I need to get the service manual, but I have just not been able to get by a dealer lately.
Thanks for your time,
Adam
I guess I am just going to take the cheaper route for now and put a stock black one back on. Then I will just get the chrome cover for it. Just wondering if any of you all know where a good place to find a take off would be? If now I will just browse Ebay.
Also, do you all happen to know what fluid would be used in an 05 Road King Custom braking system? I have been told by a few people that they were still using DOT 5 that year. My rear master cover says DOT 4 so it leaves me a little confused. I know I need to get the service manual, but I have just not been able to get by a dealer lately.
Thanks for your time,
Adam
#3
#4
Clean the caliper pistons per the attached link:
http://www.lyndallracingbrakes.com/service_tech.htm
Typical of an older bike with some miles, the pistons accumulate brake dust on their surfaces and in the piston bores so they don't move smoothly and require more hydraulic pressure (increased lever movement) to move, even with an OEM or aftermarket m/c in perfect operating condition.
Also, HD's OEM rubber brake lines tend to swell with the increase line pressure rather than directing the pressure to the caliper pistons, so installing stainless braided lines helps prevent swelling and direct the hydraulic pressure to the pistons.
But start by cleaning the pistons. An HD tech at my dealership told me about this a couple of years ago and, after doing it, the hard lever was like a miracle compared to the long pull the lever previously required.
Carl
http://www.lyndallracingbrakes.com/service_tech.htm
Typical of an older bike with some miles, the pistons accumulate brake dust on their surfaces and in the piston bores so they don't move smoothly and require more hydraulic pressure (increased lever movement) to move, even with an OEM or aftermarket m/c in perfect operating condition.
Also, HD's OEM rubber brake lines tend to swell with the increase line pressure rather than directing the pressure to the caliper pistons, so installing stainless braided lines helps prevent swelling and direct the hydraulic pressure to the pistons.
But start by cleaning the pistons. An HD tech at my dealership told me about this a couple of years ago and, after doing it, the hard lever was like a miracle compared to the long pull the lever previously required.
Carl
#5
Thanks for the information so far. Here is the problem that I am facing at this point. When I took the bike in to the local Indy that I and most everyone I know uses, he said that it looked like the two fluids may have been mixed. He flushed out the whole front system using denatured alcohol. He told me that the 05 models used DOT 5 and used it to refill it.
The front brakes work well, I just have to squeeze a little farther as I previously mentioned. I guess I will need to flush it again and get it back to DOT 4, unless it is not a problem to just leave the DOT 5 in there and keep filling it with that when it needs it.
Thanks for the input.
Adam
The front brakes work well, I just have to squeeze a little farther as I previously mentioned. I guess I will need to flush it again and get it back to DOT 4, unless it is not a problem to just leave the DOT 5 in there and keep filling it with that when it needs it.
Thanks for the input.
Adam
#6
Thanks for the information so far. Here is the problem that I am facing at this point. When I took the bike in to the local Indy that I and most everyone I know uses, he said that it looked like the two fluids may have been mixed. He flushed out the whole front system using denatured alcohol. He told me that the 05 models used DOT 5 and used it to refill it.
The front brakes work well, I just have to squeeze a little farther as I previously mentioned. I guess I will need to flush it again and get it back to DOT 4, unless it is not a problem to just leave the DOT 5 in there and keep filling it with that when it needs it.
Thanks for the input.
Adam
The front brakes work well, I just have to squeeze a little farther as I previously mentioned. I guess I will need to flush it again and get it back to DOT 4, unless it is not a problem to just leave the DOT 5 in there and keep filling it with that when it needs it.
Thanks for the input.
Adam
#7
I had a similar problem. The piston-cleaning made a huge difference - Found out that I had one piston stuck on the left and two stuck on the right. It's a cheap and 1-2 hour "fix." Even if it doesn't solve all problems, it definitely won't hurt to clean the brake calipers/pistons really well!
Thread
Thread Starter
Forum
Replies
Last Post