Trike rear master cylinder problem ??

[Pre-1898]

Hi everyone, I have converted my 2000 yamaha VStar 1100 to a trike and the rear master cylinder does not seem to move enough brake fluid to make the rear drum brakes work properly. I have adjested my brake , I bled the system bu still not enough stopping power.

Can anyone help me ? will I need to swith the master cylinder ? If so what will I need to buy ?

thanks for your help !

[Dennis Elliott]

To start you need to puit a 10# residual valve in the line.one on each side, that should do the trick. it holds presure in the line takes less to engage the drum.
You can find them on ebay or a hotrod shop

[Pre-1898]

Ok thanks for the tip ! My rear brake line makes a " y " do I still need to put two residual valve or one between the master cylinder and the " Y " splitter would do ? the way my brake lines are made between the wheel cylinders and the " Y " splitter it can be a bit difficult to put the residual valve. so I am wondering if one just behind the master cylinder would work ?

[pcombe]

I finally got past that problem with a power bleeder, Took some time and was frustrating but it worked.

[Pre-1898]

My brake line ' Y ' splitter is at the highest point of my rear swing arm, therefore much higher than my master cylinder. Shall I relocate it in order to keep it the lower possible ?

[pcombe]

I would sure be a lot more comfortable with y splitter being below the level of my master cylinder.
If you develop a leak on the master cylinder seal i would think gravity would take over and drain the fluid out of the lines?
I really don't know your set up.
When you say there is still not enough stopping power, am i to assume your pedal travel dosent feel like you have any brakes?
Or is it a matter of using the brake enough to wear the glaze from the brake pads?
I sure wouldnt discount the use of the residual valve, the man sounds like he knows what he is talking about.
I really can't answer your question about one or two valves My trike has dual disc brakes.

[Pre-1898]

You are right ! when pushing the rear brake pedal it goes all the way down and it barely slow down the trike.

[pcombe]

Did you try the power bleeder?
They can be had from harbor freight fairly cheaply.
How are your slave cylinders?

[Leathel]

Is your master cylinder piston big enough to drive both slave cylinders?

[Pre-1898]

the master cylinder is the original one from Yamaha and the wheel cylinder are originally made for a 1991 Ford mustang Lx. I honestly dont know how to rate the compatibility between them.

[Leathel]

the master cylinder is the original one from Yamaha and the wheel cylinder are originally made for a 1991 Ford mustang Lx. I honestly dont know how to rate the compatibility between them.

So you have a master cylinder from a single brake setup trying to drive 2? The piston will not be able to shift enough fluid to engage the brake fully..... A trip to a brake and clutch specialist will be in order to get a mater cylinder with a larger piston, they generally don't cost much and a bigger clutch one may work well

[pcombe]

[Pre-1898]

Is there anyone here who could tell me what type of rear master cylinder I shall use for my 2000 V Star 1100 trike with rear drum brakes ?

[RSeiler]

Hi everyone, I have converted my 2000 yamaha VStar 1100 to a trike and the rear master cylinder does not seem to move enough brake fluid to make the rear drum brakes work properly. I have adjested my brake , I bled the system bu still not enough stopping power.

Can anyone help me ? will I need to swith the master cylinder ? If so what will I need to buy ?

thanks for your help !

I have the same issue, what did you end up doing?

[Pre-1898]

Ok I was told to install residual valves and to keep my master cylinder higher than my wheel cylinders. In order to have the wheel cylinders at a lower level, Shall I flip my backplates upside down so my wheel cylinder go lower ? Would that affect breaking performance ?

any help would be appreciated !

[stacebg]

if you flip em the bleeders will be on the bottom making it most impossible to bleed them
the residual valves may help
does the pedal feel spongy or bottom out or feel good just not enuff pressure

i had the same problem w a v65 honda w a subaru rear an drum brakes had several problems the drums were small diametr an had tall tires,,, mc was a little small tried several mc an different leverage... change to disks end of problem

[cavie]

What kit did you use? The manufacturer should be able to answer all your questions. My 1300 vtx Champion stops on a dime. I seldom use the front brake.

[Pre-1898]

So you have a master cylinder from a single brake setup trying to drive 2? The piston will not be able to shift enough fluid to engage the brake fully..... A trip to a brake and clutch specialist will be in order to get a mater cylinder with a larger piston, they generally don't cost much and a bigger clutch one may work well

I checked with a company who make trike kits with the same differential I used ( Ford 7.5) using the same drum brake system and they told me they are using the VStar stock rear brake master cylinder so basically It shall be OK. I wil try lowering my brake lines as they are higher than my master cylinder and will add some residual valves. was told this shall fix the problem ! hope it does !

[Sinical]

Please forgive the intrusion, but just wanted to offer some possible confirmation about what you've been discussing and also want to thank you for confirming something I had a question about as well.

I've got a 2002 Suzuki-Lehman trike and am renewing the brake system. In matching brake parts, near as I can tell, Lehman used a Ford 6 3/4" rear differential from a Mustang II (model years 1975-78) This trike is powered by a Suzuki VS800cc engine, but Lehman used a rear brake master cylinder (motorcycle) from a VS1400cc, so I believe you're probably good to go with your 1100cc trike.

On the residual pressure valves, Lehman used only one (not two) and it's probably rated at 10 psi, that goes into the "Y" fitting which is located near the top of the axle tube and then the brake lines from the "Y" fitting run along the top of the axle tubes to connect to the wheel cylinders. This is where I want to thank Y'all. I'd suspected that the residual pressure valve was a valve and not simply a brake line fitting, but wasn't able to confirm that until reading Y'all's thread here just now. Thanx very much and all the BEST with your build

[Sinical]

Just a quik-correct here.....I was wrong about my trike having a residual pressure valve. It doesn't have one. What threw me was that the end of the brake line that comes from the master cylinder and threads into the "Y" fitting has a short adapter, hex shaped, that transitions the brake line to the larger fitting that threads into the "Y". I mistakenly thought the hex shaped piece was an RPV, but it isn't.

I want to thank Lee H. Mann for giving me the right lowdown on this and also wanted to offer Y'all the courtesy of this correction.

Keep on choppin' and build on!