Question about brakes

[Guest ReinyRooster]

Working on the brakes on my '87 Royale today. The rear pads were down so I replaced them. I also checked the fronts but they were O.K. I did notice on all the brakes that the calipers were partially extended and the pads were against the discs, making it a bit difficult to get them off the disc. Should they not be more or less fully retracted when the brakes are not being applied?

[Monty]

The pads ride against the discs, with no pressure on them. When you release the brakes, the pressure is relieved, but the calipers only retract a little bit...just enough to take the pressure off.

[Monty]

Also...On all vehicles, bike or car, I clamp the brake hose with a pair of needle nosed vice grips, then open the bleeder screw to relieve pressure to the caliper. Then, I retract the caliper with a screwdriver. You want it all of the way in before you add the new pads, so that it will have room for the thicker pads.

 

Some people use a c clamp to retract their calipers, which is ok too....UNLESS... the vehicle is ABS equipped. NEVER do this on an ABS vehicle, or it could possibly cost you lots of money, as the pressure going back into the ABS unit can destroy it. Those who have done it without problems have just gotten lucky.

 

Once everything is replaced, just tighten the bleeder screw, and remove the vise grips. Pump the brake a few times, until it feels good, and then top off the brake fluid. No bleeding is needed this way.

[Holly]

and when you pinch off the line with a needle nose vice grip, you damage the hose to cause failure in the future, that is not an accepted practice in the automotive repair field,

[Monty]

I didn't say to try to pinch thru it. It doesn't take much pressure to do it without damaging the hose.

 

Is there another option without letting your master cylinder drain out all over the place, or doing the c-clamp thing?

 

I am a former ASE Tech, and that's how I learned of the ABS thing. Gave that up...too much damage to hands/wrists shoulders after all those years.

[Holly]

Also old mech, NIASE certified, books I have are still saying use c-clamp or other device to push piston back. Have seen too many people lose brakes from broken hose after using vise grip, not smart enough to realize not to pinch thru, hate seeing anyone open bleeders if they don't understand air in lines also, will check with some buddies still doing repair to see what they are doing up here.

[skydoc_17]

I usually just take a screwdriver and pry the OLD pads apart before I remove the caliper and then the pistons are in the right position to accept the new pads. I have mentioned this before, there is nothing inside a caliper that retracts the pistons or pads away from the caliper. That's why it's very important to keep the pistons clean and "free floating" so you don't warp a rotor. If when you are changing the pads, if you can't move all of the pistons with your hand then they need to be removed and cleaned, and a light hone in the piston bore. The seals can be reused if they are not torn or leaking. After the light hone, lube the piston bore with brake fluid and reinstall pistons.

Earl

[bongobobny]

Reiny, how far the pads are from the rotor is a function of runout. The worse the runout, the farther from the rotors the pads will be. If you are right against the rotors then your run out should be minimal, a very good thing.

 

There are no springs or negative pressure to retract the pistons, just the rotor going round and round...

 

 

PS I use a big ole screwdriver with some hair growing on it to spread my pads. Just even and slow force does it every time. Just make sure your master wasn't topped of before spreading the pads as you will force fluid out of the master!

[MiCarl]

Now for my .

 

I would never ever deliberately pinch a brake hose. Hate to find the hose was weakened when I needed it in a hurry.

 

I open the bleed screw and push apart the old pads with a small pry bar. Then close the bleed screw and install the new pads.

 

FWIW, if your brake fluid isn't crystal clear it should be changed. Once it turns honey colored (or even darker!) it has moisture in it. It's effectiveness is reduced and that moisture is gumming up the pistons so next time you need a long pry bar to push them back.

[Guest ReinyRooster]

O.K. guys, thanks for the input. It would app[ear then that what I found was normal. I ordered some speedbleeders today, so I'll get that done as soon as they arrive.

[Marcarl]

Now if you want to make a super improvment to your braking,, add stainless steel braided lines to your system. It's day's work, but it makes a super difference. I think Russel makes up the set to fit your scoot.

[Guest ReinyRooster]

Guess I'll have to talk to Russell. Yoo hoo.......Russell.....where are you...?????

[Evan]

Just starting to maintain and ride an 88VR that I recently bought here in Ontario. This forum has been extremely helpful. In fact, I have learned more about the VR from the forum than I think I knew about any other bike I have owned over the past 40 years.

 

I haven't yet bled the breark lines and changed the brake fluiud (I did do the clutch). The rear brakes work great, the fronts are just ok. The previous owner told me that he changed both the front and rear pads. He also said the the back rotor had to be repalced because it was warped. However, I notice a brief rear pad friction noise every wheel revolution when I drive slowly in an indoor parking area. Also, I checked the rotors after a ride and the fronts were cool, while the back was warm to hot. What is the chance of eliminating this problem without changing the rotor, and what do you all suggest I try to do this.

 

Evan

[bongobobny]

Check the free play of the rear brake pedal. There should be some, if not the master is not completely releasing causing the brakes to drag a little bit...

[timgray]

Anyone know if the new synthetic DOT3 brake fluid is safe to use in the 1st gen venture?

[skydoc_17]

Hey Evan,

The condition you are describing is not uncommon for a new owner of a bike as old as the one you have. Here is a little info about the First Gen. Braking system on your bike. The left front and rear brake are "linked" in other words when you push the brake pedal with your right foot, it activates the left front and the rear brake. When you squeeze the right hand lever it only activates the right front brake. So, If when you squeeze the right front hand lever, you have no brake then you need to address the right front caliper. If you are pushing the right side brake pedal and the rear is working but you don't feel the bike "dive" slightly then the left front caliper is not working. If you brought your bike to my shop this is what I would do.

Remove all the brake fluid from both masters.

Remove all three calipers.

With an air hose, blow thru the brake lines to check for obstructions and remove all of the old fluid.

Clean out ALL fluid from masters and check the small holes for debree.

Now for the fun part!

Remove the pads from all three calipers.

Place wooden shims where the pads were. (paint stir sticks, plywood shims etc.)

With the air hose blow into the hole where the brake line attaches, when ALL of the pistons come in contact with the wooden shims, remove one shim and repeat.

You will get to a point where you should be able to pull the pistons out, if you can't keep using smaller shims until you can.

With the pistons out, separate the two piece caliper by removing the cap screws.

The caliper should separate into pieces.

Using a pick or very small flat blade screw driver, lightly ease the pick under the seal in the caliper and remove. (SPECIAL NOTE! THE RIGHT FRONT CALIPER AND THE REAR CALIPER BOTH HAVE 8MM PISTONS! THE LEFT FRONT HAS 7MM PISTONS! ALSO INSIDE THE CALIPER THERE IS A SEAL AND A WIPER. ALL OF THESE PARTS MUST BE KEPT SEPARATE AND BE RETURNED TO THE PROPER CALIPER AND IN THE RIGHT ORDER, IF NOT THE CALIPER WILL LEAK!)

If you did a good job removing the seal and wiper it can be reused if it is not damaged.

Lightly hone all piston bores with a brake cylinder hone and oil.

Clean the caliper halves with brake cleaner.

Check the pistons for damage and corrosion, scotchbrite the outside diameters.

Clean the seals and wipers with brake cleaner and then lube with brake fluid.

NOW IT'S TIME TO PUT THEM ALL BACK TOGETHER!

Lightly lube the piston bores with brake fluid.

Install the seal first, then the wiper, making sure they are seated in their groove.

Install the pistons, cup side towards the pads.

Bolt the caliper halves back together.

Install pins, pads, pin clip and dust cover on each caliper.

Install calipers.

Install brake lines.

Fill Masters and bleed, and bleed, and bleed, and bleed!

If at this point, a single caliper doesn't function properly you will have to decide weather to do a complete rebuild with new seals or replace the caliper.

http://www.venturerider.org/forum/album.php?albumid=129

Hope this helps,

Earl

[Evan]

 

I checked the brake pedal free play and there is about a 1/4 inch. Shouldn't this be enough? I also put the bike on its centre stand and spun the back wheel. It went around for about one full turn before it stopped turning, with a minor and constant sound of pad friction. Dosen't this suggest that the rotor is not seriously warped and instead, the problem is caliper release? If so, any suggstions on likely fix? Should I start with fresh brake fluid?