83 rear brake stuck, re-built both MC and caliper, what next?

I'll jump in here for a little feedback. I also questioned the mechanical possibility of the brake pedal not returning correctly. It has been checked and there is a little play in it when at rest (like it should be). Also, pretty sure the wheel spacer is in there right. The rear wheel had not been removed from when the brakes were working correctly.

 

We are hoping the thorough cleaning of the reservoir will take care of this.

 

GR is in need of speed. The little KLR just isn't cuttin' it. Besides, spring break is coming up and I need something to ride out there. I'm tired of .

 

Keep it coming guys. You are really being very helpful. I'm not very versed on these old washing machines.

 

FYI - GR's bike is 6 years older than he is. Keeping the dream alive!

 

RR

I hope you get it sorted, it sounds like you covered damn near every base. On the flip side I bought a new KLR in 08 and farkled the shyt out of it, then rode it through several states as if it were a Venture. Down on power but it works.

I'm waiting for a break in the weather to clean out my calipers and I hope I dont end up fighting with it as you are. When you do get it sorted please post the solution. Are you using traditional DOT3 from a new container?

OK one more thing to mention, do NOT overfill the reservoir with brake fluid!!! As the fluid heats, it expands and needs more room! If there is no room in the reservoir the fluid will build up pressure in the whole system and act just like you are applying the brakes. It is a common mistake to fill the reservoir right up to the top thinking that more fluid means more stopping power, which is not the case. It should be filled about 2/3 to 3/4 up only...

OK one more thing to mention, do NOT overfill the reservoir with brake fluid!!! As the fluid heats, it expands and needs more room! If there is no room in the reservoir the fluid will build up pressure in the whole system and act just like you are applying the brakes. It is a common mistake to fill the reservoir right up to the top thinking that more fluid means more stopping power, which is not the case. It should be filled about 2/3 to 3/4 up only...

Very good advice.

Forgot to mention that to him. Thank you for the reminder.

RR

Yeppers Goldie,, maybe take a quick read here: http://www.venturerider.org/forum/showthread.php?12536-Stranded-with-brakes-sticking-and-heating-up-Read-this

Had no idea where the rear master relief vent was. How hard is it to get that L-part out?

I read somewhere the fluid level on the rear reservoir should be about 1/8" below the filler hole. That's what I aim for and have not had the rear brakes seize due to overheating.... except for once when I misadjusted the pedal play.

Well, now I'm really stumped. I have taken apart the master 4 times today trying different configurations of old parts and new, cleaned and re-cleaned it. Tried it with proportioning valve on and off. Tried two different calipers. I have a brand new brake line on. Cleaned out all the sludge in the reservoir and blew compressed air through every hole in the system. I checked that the bracket didn't have an extra spacer (i put the caliper on the rotor without being attached to the bike, it still got stuck). I've checked the return on the pedal and left the boot off the master to make sure it returned all the way. Also I made sure the system wasn't too topped off. The only part I haven't replaced is the master cylinder. I went through one big and one small bottle of dot 3. I feel like I've never spent a better $12 than on the speed bleeders I bought last summer.

Tomorrow I'm tearing both the calipers apart and building the best caliper I can out of the two. The one I rebuilt already should be fine but I'll see. I might sand down the pads some too. I have an extra set so if it doesn't do anything I won't be too bothered by it. Besides a new master, which I really don't want to buy, I'm not really sure what to do next. I'll keep posting on my progress. Thanks again for all the help. All the ideas are much appreciated.

OK lets back up a bit.

IF I understood correctly, you have;

Cracked the speed bleeder and the caliper did not release.

Cracked the banjo at the caliper and the caliper did release.

Did you try cracking the banjo at the master to see if the caliper would release?

For testing purposes take the speed bleeder out and put a standard bleeder back in. Now if you crack the bleeder will the caliper release? A speed bleeder is a check valve, that check valve has a spring. That spring will allow there to be a small amount of pressure left in the caliper and may not fully release it.

Once you go thru these steps you will have at least isolated it down to the caliper, the line or the master. Once you know which component has the issue, it is a lot easier to find the real problem with that component.

The tiny hole we all are talking about in the master is so small that it is barely visible to the naked eye. It is only around .010 inch Dia.

Hi Jeff. I believe he did find the teeny hole as he mentions using a high E guitar string to clean/clear the hole. That is what I use.

I'll mention there is an easy way to see if hole is open. With top of MC off, gently, gently squeeze lever.... You should see a ripple of fluid on the surface of the fluid. Indicating the hole is open. Squeeze to hard and a jet of fluid will fountain up in air and all over bike and you. Easy test.....

I like your thinking about tracking down the problem.

I'm wondering... Could the spring on the pedal be weak enough to let the pedal put continuous pressure on system?

I wouldn't think it could do that but.....

OK yet another possibility, a clogged banjo bolt!! Wouldn't be the first time...

OK yet another possibility, a clogged banjo bolt!! Wouldn't be the first time...

Especially if someone used pipe tape to help seal the bango bolt - found that on one of mine - not a good plan

Hi Jeff. I believe he did find the teeny hole as he mentions using a high E guitar string to clean/clear the hole. That is what I use.

 

I'll mention there is an easy way to see if hole is open. With top of MC off, gently, gently squeeze lever.... You should see a ripple of fluid on the surface of the fluid. Indicating the hole is open. Squeeze to hard and a jet of fluid will fountain up in air and all over bike and you. Easy test.....

 

I like your thinking about tracking down the problem.

 

I'm wondering... Could the spring on the pedal be weak enough to let the pedal put continuous pressure on system?

I wouldn't think it could do that but.....

Not sure here if we are talking about a rear master on a 1st Gen? If so, the bleed off hole is located way down under the res (the res has a section of hose leader from the res to master cylinder - unlike the resevoir up on the handle bar master for the front brake or clutch.. I think The bleed back hole is to far away from the res and the opening in the res is to small to be able to actually see the fluid movement down there,, possibly.. ,, or am I totally and completely lost again -

Yeppers Goldie,, maybe take a quick read here: http://www.venturerider.org/forum/showthread.php?12536-Stranded-with-brakes-sticking-and-heating-up-Read-this

 

That Marcarl might be on to something!!

Very useful post Puck.

Had no idea where the rear master relief vent was. How hard is it to get that L-part out?

 

 

I read somewhere the fluid level on the rear reservoir should be about 1/8" below the filler hole. That's what I aim for and have not had the rear brakes seize due to overheating.... except for once when I misadjusted the pedal play.

Your welcome on the link Cammy - glad you were able to find something useful therein brother!! I havent went back and reread the link but back when I did that post I included pictures of the bleed back vent in the rear master therein. Are you referring to the plastic "L" piece that opens up the area in the master where that tiny bleed back orvice is located? I am assuming you are.. If so, here is what I do = I pinch off the hose running between the res and the master so I dont lose all my fluid. Then I remove the single philips head screw on the plastic "L" cover - now pinch the cover with my fingers and rotate it back and forth while pulling outward (may have to use pliers if hasnt been done before - be careful if you do not to damage the cover). The cover is "o-ringed" if I recall - in a side of the road repair I have just slid the cover back in after clean up and applying a touch of brake fluid for lube on the oring - snapped right back together!!

While you have the cover off be careful not to move the rear brake pedal and activate the master piston - this WILL pull air into the system. What you do is take a wire from a wire brush or something similar (I carry a couple of those cheapy little freebie (with coupon at HF) wire brushes in the Maintentance Department on Tweeks and have used the wires from them for this process a couple times) - poke the hole at the bottom of the master (this will be the bleed back) - if this is where the problem is it WILL squirt when ya pull the wire out.. If it does - the caliper will release, put the cover back on, screw back in it, release the vice grips or hemostat from the brake hose leading to the res - carefully unscrew the plug bolt in the res (careful there - that res is easily broken!!) - add correct fluid to res BUT - like Bongo Bob mentioned - DO NOT FILL TO FULL!! Pump the brake pedal and she will be good to go = NO bleeding necessary!!

,,, hope I was talking about the right "L"

Especially if someone used pipe tape to help seal the bango bolt - found that on one of mine - not a good plan

,,, hope I was talking about the right "L"

That's an old post so kudos to the boss for keeping track of these small but important items.

Especially if someone used pipe tape to help seal the bango bolt - found that on one of mine - not a good plan

Any time Teflon tape or any other joint compound is used, anywhere, the last thread on the inside should be left bare. Another point that is sometimes missed is when wrapping threads, apply the wrap in the direction that will tighten it up when snugging down the bolt or nut. One more thing when using Teflon, don't over tighten. It's easy to split things due to the reduced friction.

Who knew something so simple could be made so complicated.

Not sure here if we are talking about a rear master on a 1st Gen? If so, the bleed off hole is located way down under the res (the res has a section of hose leader from the res to master cylinder - unlike the resevoir up on the handle bar master for the front brake or clutch.. I think The bleed back hole is to far away from the res and the opening in the res is to small to be able to actually see the fluid movement down there,, possibly.. ,, or am I totally and completely lost again -

Oopsies. You are right. I was confusing the second gen clutch and front brakes systems. Bad boy!!!

Banjo bolts had been cleaned and blown out with compressed air.

Keep it coming. GR is still working on this.

Current plan is to take apart the calipers (he now has more than 1) again and make sure everything is clean and installed correctly.

RR

Ok Red,, seems how you continue to be open for more brain strain - here's a couple more items accumlated from my short time of torturing the 83's..

I have found new pads dont always fit the calipers as they should. Bottom line - once installed, pads should hang freely on the pins and move effortlessly between the edges of the caliper where they ride. I usually take a file and clean edges of the pad backing (even have to remove paint from new pad edges at times to get good results) and clean the caliper housing where the pads ride. Bottom line - sticky pad contact can cause brake hangup enough to get the system into an overheat and result in a total lockup..

Another thing to look at is that little springy thingy cover that slips under the pins and rides on top of the pads. Make sure that is in good shape and back together correctly - if memory serves me correctly - the long end of that keeper goes forward.

Here is an interesting bit of info,, maybe,, maybe not.. If your pads were wearing at an angle or having sticking problems all along (just being sensitive) - its possible that your bike's rear pig was not aligned properly from the factory. Back in the day, Mom Yam offered an angular shim to adjust this alignment. basically the shim was placed at the end of the swingarm/drive shaft housing to bring the pig into alignment..

Also remember,, there is no return spring pulling the caliper pistons away from the pads - all your have there is a backing off of hydraulic pressure. Just like automotive disc brake's - there will remain a slight amount of contact between pads and rotor even in the best of situations. To help gain a "feel" for what I am talking about - you could raise the bikes front end, spin the front wheel and stop it with the front brake and then spin it lightly to feel the pad drag - now take a rubber mallet and smack the caliper(s) to fully release the piston contact on the pads and spin it again - check it out,, you may be surprised at the "normal" amount of drag present.. Couple that with the resistance to "free spinning" that the drive shaft components produce at the rear wheel and you will easily get a fair amount of drag back there.. Just a heads up for you guys so your not fighting something that is "normal"..

,,, any of that make any sense?

Oopsies. You are right. I was confusing the second gen clutch and front brakes systems. Bad boy!!!

shoot - that aint nothin brother,, I recently tried to convince Yammer Dan that his shaft drive Maxim was chain driven:yikes:

Swear to great gods of the brotherhood of the wrench my friend - someone switched the final drive's on all those Maxims during the years cause in my mind - they came from the factory chain driven

Bottom line brother - good thing we live so far apart cause if us confused wrench spinners lived closer together in bunch,,,,, well,,, your a Vet,, you know all about that "one granade" philosophy

Pucster is on to something with those pins, I have always cleaned and polished them, and have seen some in poor shape with grooves on them, etc...

I'll check with GR later today on the pins and the spring clip. I did ask him about the physical mounting of the pads, but not with the details Puc described.

Thank you all.

RR

My '83 had a bad rear brake gremlin that would lock up due to heat expanded DOT3, and a plugged expansion relief hole. Since the bleeder valve was cracked and nothing came out there was no pressure. Did fluid come out after stepping on the pedal?? The only way that could happen is the fluid was cool. What happens after running around the block a few times?? Hot DOT3 and a plugged hole will lock the rear brake up tighter than a frog's a$$. I have an extra right saddle bag that is actually burnt due to heat coming off a rear caliper. Another problem I ran into, which was self inflicted, was I reassembled the master using a silicon to lube the plunger when putting it back together. Silly Cone and DOT3 don't like each other. The rubber cone stuck to the wall of the master. Had to rebuild it again using DOT3 as the assembly lube. I don't know if anybody answered your question, but the plastic 'L' fluid supply fitting on the side of the master is held in with an 'O' ring. Take out the screw and massage it back and forth. It should come out.

Problem solved. It was the caliper. I had two of them, one of which was rebuilt. I didn't imagine they'd both be bad in the same way (or that the rebuilt caliper would be bad at all) but when I took them apart most of the seals had ripped again on the rebuilt caliper (probably ripped when I put the pistons back in on the first rebuild), and the one I bought off e bay wasn't too good inside either. Between the two of them I could salvage enough acceptable seals to make one full caliper. I did all the sanding and compressed air cleaning I needed and then took one half of one caliper and one of the other and put them back together, very conscious of the fragility of the seals this time. Put it, on bled the brakes, and pumped it about 100 times. It didn't stick. Now it's on to the next project: vacuum leaks. Thanks everyone for all the suggestions and help.

.

Glad you got it figured out AND fixed.

Vacuum leaks? With the age of the bike start by replacing ALL of the hoses. Another biggie is the seal around the center of the YCIS chamber, it develops leaks. Do a bead of sealant around the seam or do like some have done and eliminate it, as it works in theory but in actuality not so much...

YCIS? What is that? Is that the mythical Twinkie?

RR