Rear caliper dragging.

[Pasta Burner]

First off thanx to all the wonderful help on this site! I owe you all a burger and a beer if your ever in my neighborhood! So I’ve read a few different threads concerning this and rather than try to piggyback someone else’s experience I thought it would be cleaner to start a new thread. Had an issue with a pulsating pedal and when I recently swapped tires I put the washer between the wheel and caliper and solved that issue, no more pulse. I still am having the issue of a dragging rear caliper. I bleed the brakes and that didn’t help, I removed and took apart the caliper and cleaned it’s guts. I tried to get new seals from my local dealer but they didn’t have them in stock. I put it all back together and still the same issue. With the bike on a jack or center I can spin the wheel, but it’s very difficult. I then used Pucs roadside clean the vent hole method and that seemed to work a little (Although no spurt of fluid after sticking the wire in the hole, no fluid at all came out) and I could more easily spin the rear, but not like wheel of fortune or the price is right. Had too many drinks for a test ride so I called it a night. Before test ride today the brake warning indicator is now on, owners manual says this is for the front master, which I didn’t touch. Took it for a ride around the block and the pedal was spongy, but I somewhat expected that, I had already planned to bleed again after a test ride. And the rotor was insanely hot, probably less than a mile ride.

a couple of questions as some other info in other threads is a little conflicting.

1. What are the piston seals supposed to do? Just hold the fluid back or aid in retracting the piston?

2. What do good seals look like? Mine are intact, but are in no way uniform around their circumference.

3. What tool do you recommend to remove the pistons? I used an old towel a vice and vice grips. Got them out without damage, but I wouldn’t want to do that again if I can prevent it.

4. How in the hell do you get the fluid cleanly into that hole?!? I ended up using a funnel for a flask, and she was smoking like a chimney this morning burning off all the spillage.

5. what should I do next?

 

because big bikes are new to me I paid for an experienced rider course that’s coming up next weekend, aside from just riding the venture in general, I really want of take that course with it.

[videoarizona]

1st: What bike?

 

2nd: If 1st gen Venture Royale the rear and the left front are linked. Unless previous owner unlinked them. Meaning they work together when you press on the rear brake pedal. So bleeding is a different animal depending upon model and year. SDome wills ay start at the farthest point (frontleft) and bleed there. Then at the triple tree there may be a bleed that should be next. Finally the rear.

 

More info and lets see if we can get you on your ride in time.

[luvmy40]

There are a couple tried and true methods of removing stuck or sluggish pistons. First try a rubber cone nozzle on an air blower fitting. Put a thin piece of luan or ply wood between the pistons, then jam the rubber cone into the brake line connector orifice and squeeze the blower valve. Make sure to keep your fingers clear 'cause when the pistons let loose with this method they are moving fast and furious!

 

If that doesn't work, cap off the brake line orifice and connect a grease gun to the bleeder valve. Pump the grease gun until the pistons extract. If only one piston moves, use a clamp or vice grip to hold that one in place and get the other side moving. This method is messy but it will work.

[Pasta Burner]

1st: What bike?

 

2nd: If 1st gen Venture Royale the rear and the left front are linked. Unless previous owner unlinked them. Meaning they work together when you press on the rear brake pedal. So bleeding is a different animal depending upon model and year. SDome wills ay start at the farthest point (frontleft) and bleed there. Then at the triple tree there may be a bleed that should be next. Finally the rear.

 

More info and lets see if we can get you on your ride in time.

 

 

87 VR. Brakes are still linked. I did the bleed from triple to front left to rear (as suggested in another thread) using a Mitivac. Used grease around the bleed screw threads to stop any localized air entering the system.

[Pasta Burner]

Or maybe they are not linked anymore and that’s why the warning indicator came on. I’ll have to get it up on the jack and check because I also think I noticed the hand brake was spongy too, but I chalked that up to overthinking it and I had just got back from a ride on my Duc. Gotta unbox the new Jack, just had to exchange mine at HF a few hours ago due to a broken weld joint.

[BlueSky]

The seal around the caliper piston keeps the fluid sealed so that the fluid will push the piston/brake pad into the rotor. When the brake pedal is released, a spring in the master cylinder pulls the MC cylinder back and a hole is uncovered that allows the pressure in the line to be released back to the MC. Without any pressure on the caliper piston, the caliper/brake pad will move a tiny bit back from the rotor due to irregularities in the rotor pushing it back. If the caliper is not releasing it's grip on the rotor, the caliper piston is sticking or the pressure is not being released back to the MC.

[videoarizona]

87 VR. Brakes are still linked. I did the bleed from triple to front left to rear (as suggested in another thread) using a Mitivac. Used grease around the bleed screw threads to stop any localized air entering the system.

 

Not sure I understood you correctly. You need to bleed left front. Then center. Then rear. All using the rear brake pedal or a tool as you did.

 

Check alignment of rear calliper. Loosen 2 bolts holding caliper arm and make double sure washer is in right spot. I'm not going to guess where as I'll problem get it wrong!

 

Check torque on caliper holding bolts to arm.

 

Take rear master reservoir off of master cylinder. Check connection between both.

Spray brake clean in master cylinder. Make double sure the bleed hole is open. I use a high "E" guiter string.

 

Make sure pistons move freely. They should retract just a teeny bit when pedal released.

 

If none of this works...

 

Take off rear wheel. Put axle back in and see if it slides in/out easily. If yes put wheel back in.

If no... Continue...

 

With rear wheel off....loosen 4 nuts holding rear end to swing arm. Put axle back in to use as an alignment tool. With those 4 nuts loose... You should be able to move the rear end shaft so the axle moves freely. Tighten nuts and put rear end back together.

 

I'm hoping someone else will jump in at some point with ideas I've forgotten!

[suds]

FYI... I've used https://www.brakecrafters.com/ for rebuild kits for the calipers. They're high quality seals, fairly priced and include seals for in between the caliper halves.

 

Sent from my SM-G955W using Tapatalk

[Pasta Burner]

Brakes are still linked.

[Pasta Burner]

Thanks all, I will bleed again this time Front left, then center, then rear and see where that gets me. What’s the easiest way to remove the reservoir? Removing the seat?

[luvmy40]

I don't think you have to take the seat off to remove the rear brake reservoir. I could be wrong, it's been a while since I had mine off.

[cimmer]

You should be able to access the rear master cylinder and reservoir by removing the right side panel and shouldnt have to remove the seat.

The proper bleeding steps are listed in the service manual on page 6-21.

First bleed the Right Front caliper with the front brake lever.

Second is to bleed the Left Front Caliper with the rear brake pedal or bleeding device.

Third is to bleed the Rear Brake Caliper with the rear brake pedal or bleeding device.

Forth is to bleed the Metering Valve with is located up by the top of the triple tree. You do this one last as it is the highest point on the braking system and should be where the air in the lines if there is any would be located at.

While doing all this bleeding make sure the reservoir is always full so you arent pumping air back into the system. I have found that using a mustard or catsup dispenser bottle with the brake fluid in there makes it easier to fill the reservoirs.

 

On thing to note is that the hose are getting soft and not letting getting the full pressure get to the calipers. I replaced mine with steel braided hoses and the brakes worked 100% better. I could put my hand around the hoses and apply the brakes and feel the hose swell in my hands before replacing them. So just something else to think about as these are 30+ year old bikes also the caliper rebuild kits from BrakeCrafters includes the small o-ring between the caliper halves so you can spilt them to aid in the cleaning and have a fresh o-ring to replace them with.

 

Hope this helps.

 

Good luck

 

Rick F.

[videoarizona]

Interesting, Rick...I thought the center was 2nd in bleeding. Somewhere I actually wrote that down from info on this site. Reasoning was something to the effect of not wanting any air bubbles on top to move around...causing a new re-bleed.

 

Manual has been wrong before??

Anyone else confirm?

[Pasta Burner]

Gonna hopefully get to this tonight. Great tip on the squirt bottle, gonna check wallyworld on the way home.

[cimmer]

Interesting, Rick...I thought the center was 2nd in bleeding. Somewhere I actually wrote that down from info on this site. Reasoning was something to the effect of not wanting any air bubbles on top to move around...causing a new re-bleed.

 

Manual has been wrong before??

Anyone else confirm?

 

You could be correct as we know the manual isnt always correct.. I looked in the library and didnt see anything mentioned about it. Might be do the lower bleeders and wait a day to bleed the high one.. give the air a chance to rise to the top..

 

Rick F.

[Prairiehammer]

Interesting, Rick...I thought the center was 2nd in bleeding. Somewhere I actually wrote that down from info on this site. Reasoning was something to the effect of not wanting any air bubbles on top to move around...causing a new re-bleed.

 

Manual has been wrong before??

Anyone else confirm?

 

Yamaha has had three different procedures/sequences over the years for bleeding the brakes.

In the first service manual for the XVZ12, there was no mention of which caliper to bleed first and no mention at all about "high side" bleeding.

In a Tech Bulletin, dated August 1985 (XVZ12), there is a recommendation to bleed the high side FIRST, (by cracking the banjo bolt at the metering valve).

Finally, in the XVZ13 Service Manual and Assembly Manual, the sequence stated by cimmer, is recommended.

[videoarizona]

Thanks, Kevin...guess that's why I was confused...

[Pasta Burner]

Well SF had the exit gates jacked up all week at my base causing at least an hour delay getting home, took my class yesterday on my other bike and still learned a lot and learned I have more to learn. Finally got a chance to look at the venture today and looks like the caliper and spacers and everything is aligned correctly. Took off the reservoir and cleaned it, not really dirty just a little dark brown skim of scum on the bottom. Happened to have recently changed a high E on one of the guitars and had a decent amount of leftover to cut off and stick in the master hole. Still nothing major came out, but I don’t think that’s the issue. Bled the system using the front right/rear/top method and that made more sense to me. Front caliper is letting go as it should so that makes me believe the master is doing what it should and the culprit is the rear caliper. I’ve read about swapping front calipers for R1 /R6 is there a rear full upgrade before I order new seals for stock one?

Also I noticed only the outside pistons on the rear really seem to be moving they are at least three times more exposed than the inside pistons, and when I pushed on the pedal I could see them move out and back in when released.

[BlueSky]

Seems like I remember that skydoc has an option for a different rear caliper? I think I've read that the R1 caliper will work on the rear but the bleed valve is in the wrong place and you have to remove the caliper to bleed it. Going on a foggy memory here!

[Pasta Burner]

Trying to upload photos. I took the rear tire off, axel seemed to move smoothly but went ahead and loosened the rear drive and wiggled it around (don’t think it did much) and tightened it all back up. Bled the system again, put the tire and everything back together and my suspicion from before today is confirmed. Something is out of alignment. The inside pads with all the pistons retracted are dragging on the rotor. It’s like the caliper needs to move inboard 1/8 inch or so to be centered over the rotor. I thought maybe I needed to tighten the axel a little more but there is a clear “that’s tight enough” point using my calibrated elbow. The rotor has an offset in the favorable direction (outboard) but not enough. I thought maybe I had the caliper bracket on wrong but it only fits one way. I’m stumped. Maybe it’s not an original rotor or caliper? The only thing I can think to bandaid this is add a spacer on the caliper bolts between the caliper and bracket to center it.

[Pasta Burner]

Pics

[Prairiehammer]

It appears that you have the rear axle "stack" incorrect with a washer against the wheel, whereas the washer should be outboard between the bracket and shoulder on the axle.

 

Edited July 24, 2020 by Prairiehammer

[Pasta Burner]

That makes sense to me but is in direct contrast to my previous thread about a pulsating pedal.

 

https://www.venturerider.org/forum/showthread.php?145222-Pulsating-rear-87-VR

[Prairiehammer]

I don't know what to tell you. But your complaint about the misalignment of the caliper is because of the incorrect washer placement.

 

The pulsing brake pedal is likely caused by a warped rotor (either rear or left front). Dragging pads will overheat the rotor, causing a distortion of the rotor. The rear rotor is a "floating" rotor, whereas the front rotors are rigidly mounted to the wheel. Perhaps the left front rotor is warped?

[Pasta Burner]

I don't know what to tell you. But your complaint about the misalignment of the caliper is because of the incorrect washer placement.

 

The pulsing brake pedal is likely caused by a warped rotor (either rear or left front). Dragging pads will overheat the rotor, causing a distortion of the rotor. The rear rotor is a "floating" rotor, whereas the front rotors are rigidly mounted to the wheel. Perhaps the left front rotor is warped?

 

Thanx! As soon as I get hot enough to get outta the pool I’ll swap that washer right back to where it originally was, on the outside. Before I do that I’ll use the current setup to spin the wheels to see if there is any obvious warp.

 

is there supposed to be anything special about the washer? Shape, thickness, etc...? When you get somebody else’s project, you never know what’s been messed with.