Join Date: Nov 2003
Location: Fulltiming in an RV
Brake Fluid Maintenance
After two years and over 3300 miles, I figured it was time for fresh brake fluid. The front brakes felt mushy after the last ride, which is a good indication of fluid in need of a good bleeding.
ATV brake systems use insanely small amounts of brake fluid, so this job is minimal compared to that of a car. I spent many hours bleeding the brakes on my '86 Corvette race car, so this was a welcome change.
The fronts are super easy... remove the cap on the reservoir, and put a clear hose over the bleeder valve on one of the front calipers and loosen it 1/4 turn with an 8mm wrench.
Then pump the brake lever a number of times to pump the old fluid out. Be very careful to NOT run the reservoir dry. Leave about 1/4" or so in there, even if it's dark brown like mine was. Fill it carefully with fresh fluid (keep in mind it holds about 1.5 oz at most) and repeat the process. Continue doing this until all the fluid in the reservoir is clean, and nothing but clean, bubble-free fluid is coming through the clear hose into your container that catches the old fluid.
When this is done, tighten the bleeder valve on the caliper, remove the hose, and replace the dust cap over the bleeder. Repeat the process on the other caliper. It will only take maybe one reservoir-full of fluid this time since we're just flushing out the old fluid in the line between the reservoir and the caliper. Again, be sure there are no air bubbles in the fluid coming out. If there is, keep pumping and keep adding fluid until it's 100% bubble free. Failure to do this will result in a mushy feeling from the brake lever when braking.
The rear is a little more work. The bleeder valve is acessed from the left side of the quad behind the right tire. If you have an ATV lift, put the quad on it because it will give you more room to stick your head in between the tire and fender to reach the valve.
The rear brake has its own reservoir. This is accessed by removing the seat and the right side panel. It's a little round thing. You will need a small container or funnel to fill it. This thing holds maybe 1 oz of fluid, so be careful not to spill brake fluid all over everything.
Repeat the process with the rear brake lever as you did with the front. It only takes about two full reservoir flushes to get everything out. Then top off the reservoir up to the Full line, and put the cap back on and close the bleeder valve on the rear caliper. You're now done!
I noticed a big difference in how the front brake lever felt after changing the fluid. The fluid in the front was very dark and definitely in need of changing. The rear was only barely starting to turn, but I wanted to do both since I was at it. I think I will have to tighten the cable on the rear brake lever a little to get the optimum feel from it. I'll work on that this weekend.
So that pretty much concludes my maintenance on this thing for a while. The oil has been changed, both differentials have been changed, the coolant has been flushed, and the primary clutch has been cleaned. I will check the spark plug soon and replace or regap as needed. I still want to put a new belt on, but my budget prevents me from spending $90 on one. When I measured the belt thickness before, it was 55% worn, and that was with 1200 miles of use on it. I'm kinda thinking I can get by for the rest of the year on this belt, and then change it next year when I clean the primary clutch again. We'll see.
The wheel bearings appear to be okay, but I do think it may be time to change the tie rod ends and balljoints. The downside is these parts together will cost $300-400, which I definitely don't have to spend since a $90 belt is a problem. It will have to wait until next year.