TLZone Forums banner

1 - 16 of 16 Posts

·
Registered
1998 TLS; 2001 TLR; 200X TLRSF
Joined
·
4,304 Posts
Discussion Starter #1
Greetings All,
My first time posting on TLZone. I've been away for awhile and it seems there is not much action on the TL Owners Board anymore. Maybe someone here can help me with my brake problem.

I'm bleeding the front brakes on my TLS after installing a new seal kit in the Tokico 6-pot calipers, new Nissin 5/8" master cylinder, and new Goodridge brake lines (seperate line for each caliper, not the cross-over type). I can't seem to get it to give me a firm lever feel. I've run quite a bit of fluid through the system and I'm not getting any air bubbles out of the calipers. I've also cracked open the banjo bolt at the MC to clear the air at that juction. Nothing but fluid comes out, or so it seems. Still, the lever is mushy and the brake action is weak. I have bled these same brakes before without a problem. Is there something I'm overlooking with this caliper rebuild? Could it be a defective MC? I did the rubber-band-on-the-lever-over-night trick with no results.
It feels like air in the system but I can't prove it. Any ideas or tricks I can try are appreciated.

I'm sure this topic has been discussed extensively before, but I didn't see any mention of it in the FAQ section. Thanks for your help.
 

·
Moderator,
Joined
·
5,038 Posts
Give your brake lines a tap, calpiers too sometimes air gets trapped and takes a while to work itself out, a mate of mine did mine once and we nearly laid the bike on its side and bled them, the lever was spot on after that, are you using a bleeding kit on the bleeding nipples and sucking:O
 

·
Registered
Joined
·
2,646 Posts
I eventually used a syringe to push fluid from the calipers up to the master cylinder.do this with the pistons pushed in..I had to do this several times per caliper..put the calipers back on the bike before pumping the lever or one or more pistons may pop out wasting your time. your dust seals may be sticking to the pistons partially retracting them each time you release the lever. ...does the lever firm up or does it hit the bars when pulled.It took me at least 6 hrs of messing about with mine.
 

·
Scooter hottie chauffeur
Joined
·
4,663 Posts
For get it, I just read the ENTIRE post...you already did this.




if it's the front brake... sometimes a little bubble gets caught at the top of the outlet of the MC where the banjo bolt goes in. Put a little pressure on the lever, just crack the banjo bolt with a rag or paper towl wrapped around the joing....

just give the lever a little squeeze and then tighten the banjo bolt back up...

hope this helps.
 

·
Registered
1998 TLS; 2001 TLR; 200X TLRSF
Joined
·
4,304 Posts
Discussion Starter #6
Thanks for your response Gents. Looks like I'll have to spend more time tapping lines and leaning the bike over. I've used both methods - with and without the MightyVac bleeder. It's good for getting the volume of fluid into the system, but the smaller bubbles were easier to spot using the "old fashioned" method.:confused The lever does firm up, but it is no where near what you would call a "good brake." Another thing I haven't tried yet is cracking the banjo bolts on the calipers themselves. I'll give that a go when I have time to play with it again. Again, I appreciate the help.
 

·
Registered
Joined
·
4,197 Posts
I have to ask: When you replaced the seals on the calipers, did you put the inner seals the right way in?

Greetings
Rufer
 

·
Registered
1998 TLS; 2001 TLR; 200X TLRSF
Joined
·
4,304 Posts
Discussion Starter #8
Uhhhh........Now you have me wondering. I don't know:dowhat . Could that be the issue? I don't have any fluid leaks. And there are ZERO air bubbles coming out of the bleeder valves - not even tiny bubbles. How critical is the direction of the seal? It may be something else to check - when and if I get to the point of a complete disassemble again.
Maybe if I let a "qualified" mechanic work on my bike I'd have fewer problems.:banghead But I do enjoy working on it when it cooperates.:) Thanks for the note.
 

·
Premium Member
Joined
·
7,697 Posts
Is it firm once the pads are on the disc? Is it really mushy like air in there, or just a lot of initial lever movement indicating that the pistons are retacting between uses farther back than you're used to? The pistons retract from the seals deforming before they slide, so the new seals will affect that feel. So will dry assembly. I've never had to take the TOKICO's apart...

I can't remember, is there only one bleeder on each? On the rear, I had a hell of a time trying to bleed until I realized there was another bleeder (DOH!) on the other side of the disc.

Now I haven't too much real personal experience with this next technique, oly tried it once or twice, but I've see a lot of top-notch race mechanics use it and recommend it, so here goes:
They dismount the caliper, and slide a piece of aluminum between the pads (lines connected of course). Then they beat the caliper against the heel of their shoe until any big air bubbles inside become emulsified into teensie tiny little bubbles, so the fluid looks milky. Then they bleed real quickly. They swear by this technique. I'd imagine bolting the caliper to some shaker motor would do it even better. When you get clear fluid coming out again you're done.

Personally, since my ex-wife was a useless princess bitch who would never help with anything, and I don't like the little vaccum/pressure pump I've got for doing reverse-bleeds, I really really like speed-bleeder valves. That way I can really get full lever strokes, really move a lot of fluid, no air in, and can bleed quickly and forcefully. Get some!

Also, on my old TL I had the really teenise dash-whatever line...the really small cross-section line didn't expand at all, and REALLY gave super-good feel! Stoppies became really easy! But the smaller-diameter line also moves the fluid faster, so it bleeds better and bleeds with less fluid; one or two strokes of the lever flushed the lines, after that it's just dealing with what's in the caliper.
 

·
Registered
1998 TLS; 2001 TLR; 200X TLRSF
Joined
·
4,304 Posts
Discussion Starter #10
Good point Cyclecamper. The elasticity of the new seals is probably responsible for part of my new found lever travel. However, even after the pads contact the disc and the lever firms up it is still mushy and the brake action is poor.

The 6-pot Tokico calipers only have one bleeder.

I was thinking of doing something similar to the "race mechanic" procedure you described. Right now I'm looking for a whole in my schedule so I can get back to the TL and try these tweaks.

Those speed-bleeders seem like a good idea, and I've heard other good reports about them. Do you have to use teflon tape or heavy grease on the bleeder threads?

Thanks for you input.
 

·
Premium Member
Joined
·
7,697 Posts
They come with some kind of permanent red rubbery thread sealant. Indeed, you hit upon the weak point in the speedbleeder system, if air bypasses the one-way valve and gets into the caliper. In real use, its not a problem.

They also make really trick stainless ones with an o-ring seal, but you have to have a specially-shaped hole in the caliper.
 

·
Registered
Joined
·
200 Posts
I did the same basic mod to my front brakes with the six pots, 5/8, dual steel lines. It really feels like there is air in the system even after bleeding many, many times. Mity vac, push/pull fluid, even motion pro's bleeder that pushes fluid "up" the system. Experts say it is common to get 2 bubbles, one at the top of each of the line's bajo fitting at the master cylinder. I even took my master off of the bar and proped her up sideways trying to get the bubbles to flow up through the master cyclinder let her set over night, this really helped, but there is still room for improvement. Keep at it...
 

·
Premium Member
Joined
·
4,829 Posts
Keep after it would be my opinion. I had to put a Liter of brake fluid through my system after replacing the m/c, SS lines, and 6 pots. I had the best luck with a compressed air powered vacuum bleeder that I got at Harbor Freight for $28.

Remember to bleed the caliper furthest from the m/c first. Most SS line kits for the TLR & TLS are the same length I believe, but I've always started with the left caliper, then done the right. I use a rubber hammer on the calipers to release any air bubbles, then shake the lines, then use the rubber hammer to lightly hit the m/c as well. Any bubbles stuck to the sides usually come loose. Then bleed, bleed, bleed and obviously don't EVER let your fluid reservoir go empty or you get to start all over.

If you can't get the lever to be completely solid on bottom out, go ride the TL around and let things warm up, hit a few bumps, jostle things around. A lot of times this will get air bubbles to travel to the highest point so you can get them out.

:ytiller

--Sk
 

·
Registered
Joined
·
602 Posts
One problem with upgrading calipers is you get a brake that has a larger surface area, so more fluid/pressure is required to effectively engage the brakes. If you upgrade the brakes/calipers and not the lever and piston in the master cylinder, you will often get a less responsive feel in the lever. The only GUARANTEED way to eliminate this and aquire the tight feel you're looking for is to replace the piston at the master cylinder with a larger displacement piston that will push more fluid creating more pressure per square inch... This may not apply to your scenerio if you haven't done anything like increased pistons or brake pad surface area, or added another caliper, but still good to keep in mind.
 

·
Registered
Joined
·
602 Posts
Also, I've used the mityvac vacuum system, and the Actron bleeder kit, and the Actron has worked better for me. It maintains a better seal, and creates more suction per squeeze than the mity vac did. It also comes with a little extra hose length, which is helpful if you're doing the job alone. You can get the Actron Bleeder kit at most Advance Auto Parts stores in the US
speedking said:
Keep after it would be my opinion. I had to put a Liter of brake fluid through my system after replacing the m/c, SS lines, and 6 pots. I had the best luck with a compressed air powered vacuum bleeder that I got at Harbor Freight for $28.

Remember to bleed the caliper furthest from the m/c first. Most SS line kits for the TLR & TLS are the same length I believe, but I've always started with the left caliper, then done the right. I use a rubber hammer on the calipers to release any air bubbles, then shake the lines, then use the rubber hammer to lightly hit the m/c as well. Any bubbles stuck to the sides usually come loose. Then bleed, bleed, bleed and obviously don't EVER let your fluid reservoir go empty or you get to start all over.

If you can't get the lever to be completely solid on bottom out, go ride the TL around and let things warm up, hit a few bumps, jostle things around. A lot of times this will get air bubbles to travel to the highest point so you can get them out.

:ytiller

--Sk
 

·
Registered
Joined
·
8,965 Posts
He has the right sized M/C. The problem is still probably air (could be hte seals, but air is most likely). Clamp the lever down and let it sit overnight, tap it a lot and check it tomorrow.
 
1 - 16 of 16 Posts
Top