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Bounty Hunter

Disk Brake Conversion Poor Performance

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Howdy ATV Honda Brothers and Sisters,

Well, we wanted better braking performance on our old Honda Foreman...two of them...a 1996 TRX400 Foreman and a 1997 one. Both had worn out drum brakes. We purchased and installed "SuperATV" disk brake conversion kits for both, the process was pretty easy and everything went together really well...but the braking performance of the new disk brakes isn't anything impressive...not much better than before. Clamp the lever hard, even at 10 mph, and it takes a bit for the machine to stop. So, I figure we must have done something wrong or messed up a step. So far, my thoughts are:

1.) Disks and pads have to break in? We only have about 10 miles of trail riding on them, maybe it takes time to have the brakes work their best?

2.) Expecting too much? I thought they would work much better. We have a 2011 Honda Rancher with OEM front disk brakes...and they work amazing! Crazy strong brakes on that machine...can lock the front wheels easily...which is nice cuz it often hauls a trailer.

3.) Didn't bleed brakes properly? We were super careful...i think...and bled the brakes very thoroughly. Made sure new clear DOT4 ran out each side, no bubbles. Levers are not spongy.

4.) Master cylinders not working correctly? We bought both machines used, and master cylinders looked like the brake fluid has never been changed. Fluid was brown-red colored. we flushed it all out and installed new fluid. 

5.) Brake lines old and worn out? Should we have replaced the old OEM brake lines as a matter of course because of their age? 

Thanks for your suggestions, much appreciated. Where we ride these machines it is all very steep terrain...steep enough hills good brakes are very important...

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Howdy!

 

As you mentioned it could be a number of things.

I have never used a drum to disk kit so my experience with those is limited but in general your thoughts are correct, they should be stronger.

 

Could be an installation issue.

I would start with cleaning all the residue off and going from there. If there is any grease from manufacturing left over on the rotor it can make the brakes really slip easily.

91% Alcohol and a towel is a good place to start and see if the "bite" of the pads gets better from that.

 

Another thing to consider that you mentioned is old brake lines.

You said that the lever is not spongy so it's almost ruled out but if your lines are "ballooning" it can take up a bit of the pressure meant to be delivered to the pads.

 

Start with cleaning though maybe.

oh400ex

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Hey oh400ex, thanks for the reply!

We were very careful about the disks and pads, knowing that grease and oil contamination can ruin their braking performance, so we were very mindful of that as we assembled the kit. After everything was together, we carefully cleaned the rotors with alcohol to make sure even oil from our paws was off the disks. 

I"m wondering if it would be worth it to rebuild the master cylinders? 

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Posted (edited)

Shade put you up to this post, didn't he! 

 

He was giving me crap last night as he doesn't like the Super ATV kit. I just ordered one for my 450 foreman.

 

I saw Fish mention clamping the hose coming out of the master cylinder wiht a pair of vice grips(while protecting the hose from damage). Then squeeze the brake lever. If its hard to squeeze, that shoud tell you that the master is bad. My knee jerk is either its not bled right or the master is bad. I think he said a rebuild kit for the master is like 40 bucks.

 

I also had a friend that was bleeding a motorcycle. He was letting the master go dry before refilling. Took him hours to bleed it. Just a thought.

Edited by 87Iroc

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Bleeding these things can be a PITA.  Try tapping on that block while bleeding (takes two people).  Air can get hung up at that junction.

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Hey guys, thanks for the input...I agree bleeding the brakes on an ATV is a PITA...we pulled out all the tricks in Felix's bag (you all old enough to remember Felix? 😉)

We used a Mighty Vac to vacuum pump the lines as well as bleed them with the master cylinder. We tapped everything with a plastic mallet to try to shake loose any bubbles. 

Pretty sure we were good once we had only clear new DOT 4 coming out of the bleeder fitting. BTW the bleeder fitting is really close to the banjo, and getting at it to open and close it is a tight fit. 

Mrs. Bounty Hunter and I make a great team, and like jeep said two people are definitely a plus for that operation.

I'm still at a loss for why the poor performance...master cylinder looking more like the culprit...Maybe...

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14 minutes ago, Bounty Hunter said:

master cylinder looking more like the culprit...Maybe...

 

I agree.

 

Or maybe Shade is right again and you should have skipped this particular kit 🤣

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ya know...some times...i really hate being right !..lol. i installed the high lifter kit, and i can pull my front brake lever on my '03 trx450fm, and it will lock up the front brakes real quick !.

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On 8/19/2020 at 9:19 AM, 87Iroc said:

Shade put you up to this post, didn't he! 

 

He was giving me crap last night as he doesn't like the Super ATV kit. I just ordered one for my 450 foreman.

 

I saw Fish mention clamping the hose coming out of the master cylinder wiht a pair of vice grips(while protecting the hose from damage). Then squeeze the brake lever. If its hard to squeeze, that shoud tell you that the master is bad. My knee jerk is either its not bled right or the master is bad. I think he said a rebuild kit for the master is like 40 bucks.

 

I also had a friend that was bleeding a motorcycle. He was letting the master go dry before refilling. Took him hours to bleed it. Just a thought.

i had nothing to do with this thread ?!!..lol. do you folks think i just enjoy telling you noobs what, and what not to use just to waste my time ?..lol. i tell you what to use...BECAUSE I HAVE BEEN THERE, DONE THAT, SEEN IT, AND KNOW WHAT I AM TALKING ABOUT !..LOL.

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On 8/19/2020 at 10:36 AM, Bounty Hunter said:

Hey guys, thanks for the input...I agree bleeding the brakes on an ATV is a PITA...we pulled out all the tricks in Felix's bag (you all old enough to remember Felix? 😉)

We used a Mighty Vac to vacuum pump the lines as well as bleed them with the master cylinder. We tapped everything with a plastic mallet to try to shake loose any bubbles. 

Pretty sure we were good once we had only clear new DOT 4 coming out of the bleeder fitting. BTW the bleeder fitting is really close to the banjo, and getting at it to open and close it is a tight fit. 

Mrs. Bounty Hunter and I make a great team, and like jeep said two people are definitely a plus for that operation.

I'm still at a loss for why the poor performance...master cylinder looking more like the culprit...Maybe...

Did you use the Mighty Vac to draw fluid through the lines? I have had this kit for a number of years now and it works great for me.

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Bounty Hunter , sorry your thread has turned into a " what is the best brand disc kit to buy " , LOL  I figure you want to get that SuperATV kit  you have already installing working satisfactory  and not change the kit at this point , so here is a shot at it ,  I have quite a few SuperATV kits in use , rode my blue 300  yesterday , lever is hard as a rock with a half pull and it will drop the front end when you brake  on hard ground 

 

Try this  pinch the rubber brake  hose right next to the crimp sleeve of the banjo fitting where it attaches at the master cylinder , the best tool to do this with would be a pair of pinch pliers , if you don't have pinch pliers , a small pair of vise grips will suffice with a piece of rubber wrapped around the hose to protect the hose , even leather or cardboard will work , you don't have to squeeze the crap out of it , for it to block the flow of fluid , so don't go crazy tight ,  pull the brake lever and if the master cylinder is good , then lever  should get hard  and not touch the handle bars and hold steady and not bleed down , by doing that step above , you can prove if the master cylinder is good or needs replacing or rebuilding before going farther and eliminate it from possible problems ---- At this point since you are having troubles , I would use a second pair of pinch pliers and pinch one hose right on side of the brake hose tee/ splitter , so you are blocking off one side and only bleeding one side at a time , now pump the lever against the pinch pliers at the master cylinder , hold the lever down , release the pliers and let the pressure go while continuing to hold the lever , just like bleeding the brakes , a shot of fluid will be forced down the hose  , then  pump again to build pressure , release while holding the lever in , repeat that process  a few times to force fluid down to the caliper , then continue doing  that procedure and start opening the bleeder valve on the caliper ---- I call it my force bleed ---- move the pinch pliers at the splitter tee to the side you just bleed , and do the same procedure again to the other side ---------- it has never happened to me but I have heard people say they had to replace the brake hoses on their bikes as they would  swell when pressure is applied , the swelling lessen the pressure on the calipers in one stroke , that is why people will say the brakes  work good if I pump them once , but the lever goes all the way to the handle bar on one pump  ----something that has happened to me is the banjo fitting hose barb that is inside the brake hose at  the caliper got  rusted inside and blocked the fluid off from ever making it to the caliper , just a dribble of fluid  ---- one of my bikes has been converted to back and front disc and hydraulics on the rear using both foot and hand masters , bleeding that one was really hard , I used a vacuum bleeder and the method above on it ----

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1 hour ago, Majorpayne said:

I have had this kit for a number of years now and it works great for me.

 

i have the mity vac too.... never let me down once ... i made a mason jar recovery tank to go with mine ... i reckon my set is over 15+ years old .. 

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2 minutes ago, _Wilson_™ said:

 

i have the mity vac too.... never let me down once ... i made a mason jar recovery tank to go with mine ... i reckon my set is over 15+ years old .. 

I couldn’t get my brakes bled after installation of this kit until I used the mity vac on it.

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 used mine when in stalled a brake banjo switch ... at the t junction.... .. while i was at that point i just went ahead and change the brake ... I'm not using disk brakes YET... I'm still gathering opinions, but the mity vac did a great job! 

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Update: We rebuilt the master cylinder, put it all back together, and successfully bled the brakes...this time we got good braking. The old Foreman stops quite quickly now, the front end dives under hard braking. Its way better than the drum brakes the Super ATV kit replaced, and might continue to improve as the pads and disks break in. This is really gonna help, some of our mountain rides have 2000 feet of elevation gain...and 2000 feet down where good brakes are really important! Our tires are only slightly taller than stock (25" instead of 24") but they are fairly heavy...12.5 wide Kenda BearClaws in the back, 10 inch BearClaws in the front. These tires are tough as nails on the sharp granite rocks these local mountains are made outta. 

Here's an interesting side note...Mrs. Bounty Hunters 1996 Foreman has been creaking and popping loudly from the chassis somewhere for weeks...we thought of many causes, checked and lubricated all the normal suspension and driveline components, but could not find the cause...until now. Turns out it was the heavy duty "Ricochet" skidplate on the ATV's chin, creaking in it's clamps. We wrapped the clamps in rubber gasket and presto...no more noise. 

Learn sumthing everyday...

Ride Safe and have a Blessed and Peaceful day!

Bounty Hunter

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maybe i'm still on the short yellow bus ?, but !!, i've done brakes on just about all honda's ( old school ) there is out there, and to this day, i've yet had to use a mighty vac tool to bleed brakes ?!!!. all you need is a pair of vise grips, bottle of brake fluid, good shoes/pads that are pre-adjusted, and its home free !.

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Bounty Hunter , did you pinch the hose to determine the master was putting out  or just took a pot luck  guess 

 

 

Shade , always more than one way to skin a cat , they didn't teach that on the little bus , LOL 

 

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I've never used the Super Atv kit, but wouldn't think it's much different than the HL one??..... I've always run HL with no issues. Pump/Pump bleed... Pump/Pump bleed... refill & good to go...

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3 minutes ago, Wheeler said:

I've never used the Super Atv kit, but wouldn't think it's much different than the HL one??..... I've always run HL with no issues. Pump/Pump bleed... Pump/Pump bleed... refill & good to go...

high lifter uses wilwood calipers , unlike the china junk super atv uses.

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Posted (edited)
6 minutes ago, shadetree said:

high lifter uses wilwood calipers , unlike the china junk super atv uses.

 

 

You know shade, I knew that! I forgot though. Yes Wilwood callipers are brand name!! Thanks for the reminder!

Edited by Wheeler
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1 minute ago, Wheeler said:

 

 

You know shade, I knew that! I forgot though. Yes Wildwood callipers are brand name!! Thanks for the reminder!

yeah..wilwood is about the best calipers on the market, well used in nascar, world wide.

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On 8/24/2020 at 12:13 PM, shadetree said:

maybe i'm still on the short yellow bus ?, but !!, i've done brakes on just about all honda's ( old school ) there is out there, and to this day, i've yet had to use a mighty vac tool to bleed brakes ?!!!. all you need is a pair of vise grips, bottle of brake fluid, good shoes/pads that are pre-adjusted, and its home free !.

Fine.

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