DavidsAwesome 1 Posted February 22, 2020 I had the hardest time changing the rear brakes on my 400 right now. Turned out, I had to back off the emergency brake to get the pads to have enough space to fit the rotor in between them. When I was backing off the emergency brake, I broke that rubber boot that sits right there, and some brake fluid came out. Not a lot but enough that I knew it was broken. When I put everything back together, I have no pressure on that rear brake. The emergency brake works great, and I adjusted it back where it needs to be... But the foot pedal goes straight down and has no pressure. I tried pumping it, to no avail. There's no fluid visibly coming out of the cracked boot, but I suspect that's my issue. What do I need to replace? Edit: 2005 HONDA TRX400EX Share this post Link to post Share on other sites
DavidsAwesome 1 Posted February 22, 2020 Can an admin move this to the correct section since I'm an idiot? Share this post Link to post Share on other sites
shadetree 5,554 Posted February 22, 2020 2 minutes ago, DavidsAwesome said: Can an admin move this to the correct section since I'm an idiot? done !..lol. 1 Share this post Link to post Share on other sites
shadetree 5,554 Posted February 22, 2020 make sure to post in new member section, alittle about yourself please :-). help will be around soon, hang tight !. Share this post Link to post Share on other sites
SlammedRanger 1,512 Posted February 22, 2020 When you removed the old pads and used a c-clamp to move the piston back into the caliper did you remove the cap on the reservoir? Should have been mounted on the side of the frame about shin high on the right side when sitting on the quad. Has a grey cap on it. If you didnt remove it its possible the pressure could have reuined something on the master cylinder. The ebrake works because it doesnt use the hydraulic pressure. It uses a cable to push on the piston manually. I would try removing the cap and bleeding the system in hopes it gets pressure again. 1 Share this post Link to post Share on other sites
shadetree 5,554 Posted February 22, 2020 3 minutes ago, SlammedRanger said: When you removed the old pads and used a c-clamp to move the piston back into the caliper did you remove the cap on the reservoir? Should have been mounted on the side of the frame about shin high on the right side when sitting on the quad. Has a grey cap on it. If you didnt remove it its possible the pressure could have reuined something on the master cylinder. The ebrake works because it doesnt use the hydraulic pressure. It uses a cable to push on the piston manually. I would try removing the cap and bleading the system in hopes it gets pressure again. this guy will get ya fixed up david !!! 1 Share this post Link to post Share on other sites
DavidsAwesome 1 Posted February 22, 2020 45 minutes ago, SlammedRanger said: When you removed the old pads and used a c-clamp to move the piston back into the caliper did you remove the cap on the reservoir? Should have been mounted on the side of the frame about shin high on the right side when sitting on the quad. Has a grey cap on it. If you didnt remove it its possible the pressure could have reuined something on the master cylinder. The ebrake works because it doesnt use the hydraulic pressure. It uses a cable to push on the piston manually. I would try removing the cap and bleeding the system in hopes it gets pressure again. I didn't, and I knew I should have done something like that! The YouTube videos I watched showed nothing like that, so I went against my better judgment. I'll look for this reservoir. I should mention that the front brakes are working fine though... Is the master cylinder just for the rear brakes? Share this post Link to post Share on other sites
SlammedRanger 1,512 Posted February 22, 2020 Yessir. Quads have completely seperate front and rear brake systems. And the opposite of the way a car works they have no by-pass valve that will let you press in the brake piston. If you force it you can do serious damage to the master cylinder or the caliper. Depending on what seal decides to be the weakest link. There should have been zero fluid behind the e-brake plate so that is my bet as to where the blow out happened. Which could possibly mean when you remove the cap and go about pressing the piston back and then bleed the system you could be ok. It hopefully just pushed a bit of fluid around the piston to relieve the pressure. But that relief of pressure would still let some air back in and that would be why your pedal is dead. Fingers crossed. 1 Share this post Link to post Share on other sites
DavidsAwesome 1 Posted February 23, 2020 SlammedRanger, Thanks a ton. I bled the brakes, and got all of that black fluid out of there. For now it seems to be doing really well. Hopefully that's all it was. Share this post Link to post Share on other sites
SlammedRanger 1,512 Posted February 23, 2020 Your welcome bud! Glad to help! You did used dot 5 correct? Share this post Link to post Share on other sites
DavidsAwesome 1 Posted February 23, 2020 The reservoir on the handlebars says DOT 4.... Do you recommend DOT 5? Share this post Link to post Share on other sites
shadetree 5,554 Posted February 23, 2020 6 minutes ago, DavidsAwesome said: The reservoir on the handlebars says DOT 4.... Do you recommend DOT 5? now this i can answer !. both are the same..except !!!!, one has a higher boiling point than the other, maybe that's why he asked ?. Share this post Link to post Share on other sites
SlammedRanger 1,512 Posted February 23, 2020 I run dot 5. You want a minimum of dot 4. But i use my brakes hard when racing so i go for the higher boiling point fluid. I always forget not everyone get brakes so hot you could cook an egg on the rotor lol. 1 Share this post Link to post Share on other sites
shadetree 5,554 Posted February 23, 2020 Just now, SlammedRanger said: I run dot 5. You want a minimum of dot 4. But i use my brakes hard when racing so i go for the higher boiling point fluid. I always forgot not everyone get brakes so hot you could cook an egg on the rotor lol. sooo..i was right ??..lol 1 Share this post Link to post Share on other sites
SlammedRanger 1,512 Posted February 23, 2020 Just now, shadetree said: sooo..i was right ??..lol Yeah spot on. Like always! LoL 2 1 Share this post Link to post Share on other sites
shadetree 5,554 Posted February 23, 2020 i may not know sport atvs very well ?, but i do know my brakes !..lol. Share this post Link to post Share on other sites
DavidsAwesome 1 Posted February 23, 2020 Okay cool. I did DOT 4, but I'll keep in mind that maybe I should run DOT 5. I didn't know about the heat rating. I've learned a lot today. lol 1 Share this post Link to post Share on other sites
shadetree 5,554 Posted February 23, 2020 Just now, DavidsAwesome said: Okay cool. I did DOT 4, but I'll keep in mind that maybe I should run DOT 5. I didn't know about the heat rating. I've learned a lot today. lol lol, like i told ya on the old site, lots of great ppl here, smart, and will help ya !. 1 Share this post Link to post Share on other sites
TRX2FiveO 42 Posted April 5, 2020 Welcome to the forums. For a great front brake upgrade on the 400ex. You can install YFZ450 front calipers any year. They are dual piston and require a lot less effort to slow down or stop your bike. Share this post Link to post Share on other sites
SlammedRanger 1,512 Posted April 5, 2020 13 minutes ago, TRX2FiveO said: Welcome to the forums. For a great front brake upgrade on the 400ex. You can install YFZ450 front calipers any year. They are dual piston and require a lot less effort to slow down or stop your bike. I couldnt bring myself to do it. Its bad enough i used a yamaha carb lol. I went with 05 trx450r spindles, hubs, and calipers. The difference in stopping power was insane. I just feather them with 1 finger and it stops way better than stock ever could! Share this post Link to post Share on other sites
TRX2FiveO 42 Posted April 6, 2020 On 4/4/2020 at 9:22 PM, SlammedRanger said: I couldnt bring myself to do it. Its bad enough i used a yamaha carb lol. I went with 05 trx450r spindles, hubs, and calipers. The difference in stopping power was insane. I just feather them with 1 finger and it stops way better than stock ever could! 🤦🏻♂️🤦🏻♂️🤦🏻♂️ you do realize there is absolutely NOTHING on the calipers that say YAMAHA! They are the exact same name as the ones on HONDA, SUZUKI,KAWASAKI.... dont be so naive and quick to deter others from buying something just because it "didn't " come off of a Honda. You dont have to spend a boat load either like you do to use 450r parts. 1 1 Share this post Link to post Share on other sites
SlammedRanger 1,512 Posted April 6, 2020 4 hours ago, TRX2FiveO said: 🤦🏻♂️🤦🏻♂️🤦🏻♂️ you do realize there is absolutely NOTHING on the calipers that say YAMAHA! They are the exact same name as the ones on HONDA, SUZUKI,KAWASAKI.... dont be so naive and quick to deter others from buying something just because it "didn't " come off of a Honda. You dont have to spend a boat load either like you do to use 450r parts. Actually i had a 05 trx450 parts quad i got mine off. And i know they dont say yamaha on them. I was just giving them another option is all bud. Did the yfz calipers require the hubs and spindles like the trx ones did? 1 Share this post Link to post Share on other sites
TRX2FiveO 42 Posted April 6, 2020 2 hours ago, SlammedRanger said: Actually i had a 05 trx450 parts quad i got mine off. And i know they dont say yamaha on them. I was just giving them another option is all bud. Did the yfz calipers require the hubs and spindles like the trx ones did? Nah the YFZ Calipers are a direct fit. nothing required to make them fit. 1 Share this post Link to post Share on other sites
SlammedRanger 1,512 Posted April 6, 2020 Wow thats crazy! The trx caliper holes werent even close to matching. It was way off! LoL. Share this post Link to post Share on other sites
TRX2FiveO 42 Posted April 7, 2020 1 hour ago, SlammedRanger said: Wow thats crazy! The trx caliper holes werent even close to matching. It was way off! LoL. Your calipers are the same as 700xx... but yeah the YFZ are much less expensive 1 Share this post Link to post Share on other sites
