[Budweiser]

96 300 4X4. A couple months ago I posted that the front brake lever had very little pull before the brakes would engage. At times they were slightly on. So I took all the advice I was given and cleaned all the front brake cylinders. Thought that cured my problem but it didn't.

So lately the brake lever has about 1/4 inch of pull before the brakes go on. I was gonna readjust them but hadn't got to it yet. Me and brother took ATV's on a easy ride...old railbed. Brakes were fine when we left but as we rode the front brake got so that the lever had ZERO play in it. So I thought I just won't use the front brakes and fix it when I get home. About 10 miles from my house I can really feel the front brakes grabbing so we stop and investigate. The brakes had been on and now both wheels have smoke coming from them. And its difficult to push the ATV by hand. As we are looking at the front tires, the black Honda center cap melts and fall off!!!! So I take out my screwdriver and loosen the wheel cylinder adjusting screw on ONE side. Immediately the ATV free wheels. HUH? I only did 1 cylinder. Anyway, I loosen all 4. Brake lever now feels proper. Brakes are applied about an inch from the grip. We ride 4 miles to our destination and I can feel the brake lever getting tighter again. We then ride home the 14 miles and by the time I get home the brake lever is tight again.

I have no idea what's going on. The rubber on all the wheel cylinders was good. I find it hard to believe that all 4 wheel cylinders are doing the same thing. Could it have something to do with the master? Remember, both wheels were smoking. So both sides were stuck on. Why after loosening 1 side wheel cylinder would the brakes seem to release on the other side and allow the ATV to free wheel? New wheel cylinders are $25.00. I could get 4 but would this solve my problem? I took the cap off the master cylinder thinking it was under pressure but it wasn't.

I am mystified!!!!!!!!!! Any advice on what I should be looking at? Sorry so long winded but wanted to give all you Honda guru's all the details.

 

[retro]

The adjusters might be tightening themselves up? Check that the little spring blade that detents the adjuster starwheels are wotking. Sometimes they can get bent a bit.

 

[Budweiser]

Yup. That was one of my thoughts too.

 

[GirlsRideToo]

I had a similar problem and it turned out to be the wheel cylinder assembly, not the wheel adjuster. If the piston on the cylinder is not working properly and keeping the brake pads pushed out, the brakes will drag. I had a tiny leak from the cylinder and my brakes did all kinds of crazy things.

The star wheel on the brake adjuster is only for adjusting the pads out to their proper position. It is the cylinder that makes the brake pads move outward when you pull the brake lever. I'm sure you know this. Just making sure we're on the same page.
Turning the star wheel to move the brake shoes inward will cause the brake shoe to make less contact on the drum and makes the brakes seem looser even if the cylinder is pushing the brake pads out too far. I hope that makes sense. Bottom line is, I think it's the cylinder causing your problem.

So, did you replace the brake adjuster AND the cylinder assembly on each front wheel?

 

[Budweiser]

I had a similar problem and it turned out to be the wheel cylinder assembly, not the wheel adjuster. If the piston on the cylinder is not working properly and keeping the brake pads pushed out, the brakes will drag. I had a tiny leak from the cylinder and my brakes did all kinds of crazy things.

The star wheel on the brake adjuster is only for adjusting the pads out to their proper position. It is the cylinder that makes the brake pads move outward when you pull the brake lever. I'm sure you know this. Just making sure we're on the same page.
Turning the star wheel to move the brake shoes inward will cause the brake shoe to make less contact on the drum and makes the brakes seem looser even if the cylinder is pushing the brake pads out too far. I hope that makes sense. Bottom line is, I think it's the cylinder causing your problem.

So, did you replace the brake adjuster AND the cylinder assembly on each front wheel?

Thanks for the reply. I did not replace any parts on the ATV. It had very little use. I did take all the wheel cylinders apart and cleaned them all. They were not too cruded up and pulled apart with ease. Rubber all looked good. The shoes are original to this machine and look new. What mystifies me is both sides are acting exactly the same. What are the chances of both sides doing the same thing? Smoke from burning brakes was coming from BOTH wheels. That's why I'm leaning toward something is up with the master cylinder. Maybe it works by pushing the brake fluid out but is not returning it? I actually just thought of that as I was writing it! I'm going to take the brakes apart tonight and make sure the tab on the adjusters is adjusted correctly first.

 

[GirlsRideToo]

Both wheels! Ouch! Sorry, I missed that minor part of the problem. LOL.

Did you repack the cylinder with grease where the piston seats?? Doubt that's the issue with BOTH wheels. Just sayin.

Yes, check the master cylinder. The rubber diaphram, in the bottom, should be pliable with no rips or tears. Also, be sure it's not upside down. LOL. Not sure if your model will let you put in it either way. Be sure the piston is clean and moving properly. Clean the MS really well and blow it out with compressed air.

My last, no so intelligent, thought is to be sure you have the correct OEM brake cable. I had trouble on my Yamaha with a All Balls cable that turned out to be about 1/4 inch too long and it was bending and binding at times. An OEM cable fixed the problem.

BTW, I have two brand new clips for the adjusters that I did not use and I'll be happy to send them your way if you like.

 

[Manny]

Just had a pristine 1994 in the shop last month with the same exact issue.

the lady was a little drunk and rode the darn thing till the drum seals caught on fire!

I replaced the wheel cylinders with OEM - new drums, drum seals, along with knew knuckle seals.


I took it out for a half days ride in the mountains and quickly found out that was not the root of the issue.

Turned out to be a bad brake master cylinder, so before you go to chasing your tail on wheel cylinders I would bet its your brake MC.

 

[Budweiser]

Haha! My drum seals were not that bad but they did seperate from the drum!

Thank you GRT for the offer of the clips but mine were all fine and making the adjusters ratchet like they should.

So its all apart and I see nothing wrong. I can pull the brake lever and see the wheel cylinders push out and then back in. So I tightened the adjusters and put one drum back on. Did the same to the other side but could not get the wheel cylinders to compress enough to get drum on. If I move 1 shoe in with my hand, the other one pushes out. When I hold both with my hand I cannot get the wheel cylinders to compress. Top is off master cylinder.

So I think its the master cylinder. I disconnected the brake line at the MC and the wheel cylinders released and drum went on easily. Then I blew air through all the lines to make sure none are plugged. None were.

So I'm going to get the MC rebuild kit. Easy to do? I haven't even tried to take this one apart yet as I like to have the parts in front of me so I immediately put back together.

Thank you for that info Manny. Very helpful. To me it seems as if the MC is not allowing the brake fluid to return.

 

[GirlsRideToo]

So I think its the master cylinder. I disconnected the brake line at the MC and the wheel cylinders released and drum went on easily. Then I blew air through all the lines to make sure none are plugged. None were.

So I'm going to get the MC rebuild kit. Easy to do? I haven't even tried to take this one apart yet as I like to have the parts in front of me so I immediately put back together

Easy to do? I did it. LOL. Very easy. My tips: Be sure to handle the rubber separator with care. Buy a new bottle of Dot3/4 brake fluid. Don't use brake fluid from a previously opened bottle. Put a little anti-seize on the screws for the cover. Those screws rust easily. I replaced mine with stainless screws.

There's a great sticky about bleeding the brakes. If you haven't already, read through it.
@retro taught me that the brake shoes need to be adjusted out so that the drum is just able to slide on. If the drum slides on too easily you've done it wrong.

Keep us posted.

 

[LedFTed]

i had a truck, think it was 76 ford, henry. any way, when i hit the brakes, the fluid would go forward, but not return. it made for awkward breaking, and turning. i had to replace the front break lines on both side's. problem solved. i doubt hondaatv has this problem, but it can happen.
maybe i'm the only one this happened to, hard to believe, though it could be so.. stranger thing's have happened. i have seen a few.

 

[Budweiser]

i had a truck, think it was 76 ford, henry. any way, when i hit the brakes, the fluid would go forward, but not return. it made for awkward breaking, and turning. i had to replace the front break lines on both side's. problem solved. i doubt hondaatv has this problem, but it can happen.
maybe i'm the only one this happened to, hard to believe, though it could be so.. stranger thing's have happened. i have seen a few.

I was able to blow air threw them so I don't think the lines are plugged. And that's not pressurized air, just air out of the nozzle. I'm thinking there must be some sort of return in the MC. Maybe its plugged. The force of my hand pulling the lever is enough to get the brake fluid to move to work the wheel cylinders but the MC is not allowing the brake fluid to flow back into the resivour when the brake is released. Which keeps the wheel cylinders pushed out and the brake lever tight. At least this is what I'm thinking the problem is! I could be way off.

 

[Goober]

Did you replace the MC seals?
When I replaced my seals the first time i put one in backward—they are directional. I slso had to scrape off a waxy looking build up on the piston. I also had to unplug the two orifice in bottom of the mc.
If you didn’t get into the mc last time then yes, I would get into it.

 

[Budweiser]

Did you replace the MC seals?
When I replaced my seals the first time i put one in backward–they are directional. I slso had to scrape off a waxy looking build up on the piston. I also had to unplug the two orifice in bottom of the mc.
If you didn’t get into the mc last time then yes, I would get into it.

AHHHHHHAAAAA!!!! So there are 2 orifice in the bottom? Maybe 1 is for outgoing brake fluid and 1 is for return? That makes sense to me and is good to know. Thanks!

I haven't touched the MC. I ordered the rebuild kit and it should be here soon.

 

[LedFTed]

i had a truck, think it was 76 ford, henry. any way, when i hit the brakes, the fluid would go forward, but not return. it made for awkward breaking, and turning. i had to replace the front break lines on both side's. problem solved. i doubt hondaatv has this problem, but it can happen.
maybe i'm the only one this happened to, hard to believe, though it could be so.. stranger thing's have happened. i have seen a few.

I was able to blow air threw them so I don't think the lines are plugged. And that's not pressurized air, just air out of the nozzle. I'm thinking there must be some sort of return in the MC. Maybe its plugged. The force of my hand pulling the lever is enough to get the brake fluid to move to work the wheel cylinders but the MC is not allowing the brake fluid to flow back into the resivour when the brake is released. Which keeps the wheel cylinders pushed out and the brake lever tight. At least this is what I'm thinking the problem is! I could be way off.

Henry, was an older truck, so it probably dont apply. i might have been able to blow air both way's through the brake lines or not. fluid though, only one way. i never seen this before, never seen it since. i just happened to be the lucky one, this happened to.. strange thing's happen. it's just a given. :wink
i clicked in on the KY Derby once.

 

[Budweiser]

So I got the rebuild kit. After I got it apart, I see the 2 orifaces. 1 is very very small. Is that correct? As is so small a I used a piece of wire from a wire brush to unplug it. Sound right?

Everything went back together as it should but now the brakes don't seem to be bleeding. The entire system was emptied of brake fluid so I'm sure it will take a bit to get brake fluid down to the bleeders but the brake fluid in the MC doesn't seem to emptying like I would expect.

Is the metal plunger supposed to go in a certain way? I just slide it in. I think its also leaking brake fluid from the plunger seal. Did not do that before.

Now I'm frustrated! Not much to screw up!

20 minutes later....I clamped the rubber brake line with vise grips. I can hear brake fluid coming out the plunger and its leaking. So I'll have to take it apart tomorrow to see what I did wrong!

 

[retro]

Was there a piston in the kit already assembled with a new cup seal on it? If so just slide it in... but note that the cup seal lip must face towards the bottom of the bore so it holds fluid pressure while applied, but can collapse to allow fluid to flow back past the seal when the piston is withdrawn by the return spring. The cup seal shape makes the master cylinder into a positive displacement pump only while the piston is being pushed into the bore, in other words.

If you have the master cylinder assembled correctly but it leaks, the bore might be pitted or burred, or its possible the new kit parts do not fit that master cylinder.

 

[Budweiser]

The kit was a Honda rebuild kit. The cup seal was not on the piston, I had to slide it on. Don't think I did it wrong, I copied the original. But I may have!

I'll take it apart tomorrow.

 

[LedFTed]

i might be wrong, but clamping brake line's, just dont seem right. ya might have to have help with bleeding, the brakes. i have..
no matter, atv's or truck's. {i left out cars, farm tractors, anything with a hydrolic brake line}, it just is...
manual brake lines, should ya run across them, a different matter. like emergency, brakes.

 

[shadetree]

my money was on the small hole in the bottom of the master cylinder. this is your return line. if your brakes are sticking like you said ^^^ ?, this tells me your return line hole in the master cylinder is clogged.

 

[shadetree]

i might be wrong, but clamping brake line's, just dont seem right. ya might have to have help with bleeding, the brakes. i have..
no matter, atv's or truck's. {i left out cars, farm tractors, anything with a hydrolic brake line}, it just is...
manual brake lines, should ya run across them, a different matter. like emergency, brakes.

and your wrong..lol. been doing it this way for over 20 years, not once have I had any issues bleeding brakes on atvs.