[Budweiser]

1996 300FW. I recently went through it and everything works perfect. Except the front brakes. The brake lever has very little if any pull. The brakes are "on". I rocked the machine and you can feel the fronts grabbing. Funny thing is sometimes the brake lever will move about 1/4 inch and then the brakes grab. 4-wheeler is not being used. This is all in my garage, different temps.

This 4-wheeler has not seen much work in its life. The brakes are near perfect. Shoes are original and very little if any wear. I emptied the master cylinder and then filled it again with fresh brake fluid. Then bled the brakes until clean brake fluid was coming out. The adjusters are all backed off as much as possible. With the drums off the brake lever moves as it should and pushed the shoes out. With the drums on, very little and at times no movement of brake lever and the brakes are working.

Strange to me why it does this. I'm leery of spending any money on the drum brakes as I think its more cost effective to just do the disc brake conversion. But I'd of course rather not spend any money and these brakes look perfect!

Could a brake cylinder be getting hung up? Any ideas?

 

[Goober]

If you bled the brakes it’s very easy for air to collect in the upper hose near the master cylinder reservoir.

First the brake shoes must be run out far enough to provide back pressure in the brake lines.

To get that air out, remove the little rubber puck from the bottom of the fluid reservoir—use a narrow flat screwdriver. Carefully rotate the handlebars to the left until the reservoir is over the hose—you want all those bubbles to flow up against the master cylinder assembly. Then jiggle the brake lever and you’ll see air bubbles rise in the fluid reservoir.

 

[shadetree]

wheel cylinders are sticking in their bore.

 

[Budweiser]

Goober, I don't think that is it. The brake lever is tight. They are not spongy at all.

Shadetree - that makes sense to me. Is it possible to take them apart and clean? Can't hurt to try if you think thats it. One of the wheel cylinders had the rubber boot filled with brake fluid when I took the drums off to inspect and clean. I took drum off to inspect after riding wheeler around yard and there was no brake fluid leaking out so I thought I was good.

I just checked the repair manual and they look pretty simple.

 

[shadetree]

Goober, I don't think that is it. The brake lever is tight. They are not spongy at all.

Shadetree - that makes sense to me. Is it possible to take them apart and clean? Can't hurt to try if you think thats it. One of the wheel cylinders had the rubber boot filled with brake fluid when I took the drums off to inspect and clean. I took drum off to inspect after riding wheeler around yard and there was no brake fluid leaking out so I thought I was good.

I just checked the repair manual and they look pretty simple.

yes, they can be taken apart, and cleaned. you need a grease gun, correct size zerk ( grease fitting to press stuck piston out ). a Dremel with a small wire brush attachment helps to polish the bores out. also would be a good idea to pull the star wheels apart, and clean them up, and grease the threads. careful : one side has left hand threads on the star wheels !! ( these are the brake shoe adjusters ). when you get all that done, and back together, there is a sticky in this section by me on how to bleed brakes.

 

[Goober]

Ok i see now i was cornfused by the real issue.

Let us know what the problem was as you find it—the boot filling with fluid sounds like a bad seal too? Might have to get a rebuild kit to replace that seal?

 

[Budweiser]

What does the grease fitting do? I’ll probably be able to answer my own question when I get it taken apart!

And Goober, yeah it’s hard to explain!! Partzilla have rebuild kits for the wheel cylinders?
Thanks for the help! I’ll get it taken apart next week and let ya know.

 

[rustynut2]

Does the lever have an adjustment on it to take up slack on the plunger. It needs a bit of play so the piston can release the pressure in the system.

 

[_Wilson_]

I gather your talking about something like this vehicle master cylinder adjustable push rod ? No there is no adjustment built into any of them, @ least not that I'm aware of .... And i don't know of anyway to easily cheat it.

 

[shadetree]

What does the grease fitting do? I’ll probably be able to answer my own question when I get it taken apart!

And Goober, yeah it’s hard to explain!! Partzilla have rebuild kits for the wheel cylinders?
Thanks for the help! I’ll get it taken apart next week and let ya know.

once apart, you put a bolt in one hole where the cross over line was, use the grease fitting in the smaller hole on the cylinder, then use the grease gun to use pressure to pop the piston out of the bore.

 

[wmgeorge]

What does the grease fitting do? I’ll probably be able to answer my own question when I get it taken apart!

And Goober, yeah it’s hard to explain!! Partzilla have rebuild kits for the wheel cylinders?
Thanks for the help! I’ll get it taken apart next week and let ya know.

once apart, you put a bolt in one hole where the cross over line was, use the grease fitting in the smaller hole on the cylinder, then use the grease gun to use pressure to pop the piston out of the bore.

Why not use some low pressure air?

 

[shadetree]

What does the grease fitting do? I’ll probably be able to answer my own question when I get it taken apart!

And Goober, yeah it’s hard to explain!! Partzilla have rebuild kits for the wheel cylinders?
Thanks for the help! I’ll get it taken apart next week and let ya know.

once apart, you put a bolt in one hole where the cross over line was, use the grease fitting in the smaller hole on the cylinder, then use the grease gun to use pressure to pop the piston out of the bore.

Why not use some low pressure air?

because it wont budge that seized piston inside the wheel cylinder !!!. if they are stuck in there good ?, no amount of air is going to move them !..lol. and iffffffffff it did ?, you run two things, one: it go flying into lala land, and you may never see it again ?, two : you run the risk of blowing the seal out when you do that with air !!. trust me on what I am saying here !!!..do it with grease, and it will ease out very slowly, and you will be fine. DO NOT USE AIR..OF ANY SORT !!!!!!.

 

[KoolBreeze]

The grease trick worked great on my ‘88 350D. Never would have believed if I had not done it. One of them was seized pretty bad and I didn’t think it was going to work but after a few pumps with the grease gun it popped right out. Took a 10mm zerk (aka alimite) on mine.

 

[Budweiser]

Well, I took 1 apart. Used the grease gun method, worked great. Smoothly pushed it out. I did not see any sign of corrosion in there. Put it all back together and I can use pliers to pull the piston in and out. I did not try pliers before. The rubber seals all look good, no tears, no dryrot.

Sound about right? I'm going to do all the rest and see what happens. A rebuild kit for 1 cylinder is $30.00. I'm leery of spending money on the drum brakes when I can spend $230 and convert them to disc and then they will basically last forever. This 4-wheeler will see very light use.

 

[shadetree]

Well, I took 1 apart. Used the grease gun method, worked great. Smoothly pushed it out. I did not see any sign of corrosion in there. Put it all back together and I can use pliers to pull the piston in and out. I did not try pliers before. The rubber seals all look good, no tears, no dryrot.

Sound about right? I'm going to do all the rest and see what happens. A rebuild kit for 1 cylinder is $30.00. I'm leery of spending money on the drum brakes when I can spend $230 and convert them to disc and then they will basically last forever. This 4-wheeler will see very light use.

if you put disk brakes on the front ?, you have to use 12 inch rims, as 11 inch rims won't clear the brake calipers.

 

[rustynut2]

I gather your talking about something like this vehicle master cylinder adjustable push rod ? No there is no adjustment built into any of them, @ least not that I'm aware of .... And i don't know of anyway to easily cheat it.

Was thinking of the brake lever on my motorcycles
like
https://www.google.com/search?biw=1......0i8i7i30.IASvCRU1WX8#imgrc=Ths5Mdx11HR-KM:

I guess your bike doesn't have them.

 

[Budweiser]

Well thank you for that info Shadetree! My rims are original. I’ll assume they are too small? I’m not home to check. If that’s the case I don’t have a problem having to fix my drum brakes. My only option!!!

 

[shadetree]

Well thank you for that info Shadetree! My rims are original. I’ll assume they are too small? I’m not home to check. If that’s the case I don’t have a problem having to fix my drum brakes. My only option!!!

your welcome . if your rims are oem factory ?, then yeah..they are 11 inch rims, you will need 12 inch rims to put disk brake kit on it .

 

[_Wilson_]

Yep @rustynut2 that's exactly what i was talking about! ..... Now i don't know why guys do do this mod to an ome master cylinder.... Instead .... I'd OP for fixing it correctly ... Here's a pic gives an idea of they drill and tap this area (where the ink pen tip is) add an adjust screw with a jam nut .... I've seen this mod ONLY twice.... The only reason I've ever gotten for this mod is.. The master cylinder bleeds off pressure, when fully released , i guess some people are cheep... Rather than fixing it correctly.

Edit: yes all three of mine have oem masters cylinders

 

[shadetree]

Yep @rustynut2 that's exactly what i was talking about! ..... Now i don't know why guys do do this mod to an ome master cylinder.... Instead .... I'd OP for fixing it correctly ... Here's a pic gives an idea of they drill and tap this area (where the ink pen tip is) add an adjust screw with a jam nut .... I've seen this mod ONLY twice.... The only reason I've ever gotten for this mod is.. The master cylinder bleeds off pressure, when fully released , i guess some people are cheep... Rather than fixing it correctly.

Edit: yes all three of mine have oem masters cylinders

why would folks do this ?. i've always fixed them the correct way, rebuild them ?, or clean them ?. i've yet to this day..not had one single oem master cylinder not work for me.